Pandas cookbook

71 rules as pandas functions: the reference twin of the SQL cookbook, for notebooks, CSV studies and the parity tests (parity). The function behind each rule is in open_fdd/rules/cookbook_catalog.py. The 6 rules without a twin are marked SQL only.

Conventions

Input is a DataFrame with a UTC DatetimeIndex and one Haystack-role column per signal, all in SI (table below). The rules never convert units or guess a scale.
run_rule(rule_id, df, params=..., poll_seconds=300) returns status (PASS, FAULT, SKIPPED_MISSING_ROLES, …), fault_hours (h), and the raw_fault and confirmed_fault boolean masks. Set df.attrs["equipment_id"] and df.attrs["equipment_type"].
The runner applies the operational gate and the confirm delay (confirm_min, minutes). Parameter keys match the SQL catalog.

import pandas as pd
from open_fdd.rules import run_rule

# one day on a 5-minute grid, UTC timestamps, every value SI (°C, Pa, L/s, kW; commands 0-1)
idx = pd.date_range("2026-01-05", periods=288, freq="5min", tz="UTC", name="timestamp_utc")
df = pd.DataFrame({"duct-static-pressure": 150.0, "duct-static-pressure-sp": 250.0, "fan-cmd": 1.0}, index=idx)
df.attrs.update(equipment_id="equip-1", equipment_type="AHU")

result = run_rule("FC1", df, params={"confirm_min": 5})
print(result.status, result.fault_hours)

Duct static (Pa) sits 100 Pa under its setpoint while the fan runs: low static at full fan.

Units convention

Rules compute in SI only. The engineer declares each point’s unit in NF; ingest converts it to SI (open_fdd/data/units.json). Unknown or incompatible units are skipped, never guessed from the value.
Imperial is display-only. Differences (Δ°C) convert with a factor of 1.8 and no +32.
Fractions are 0-1, relative humidity is 0-100 %RH, statuses are 0/1.

Quantity	SI unit (rules compute in this)	Imperial display	Also accepted (converted at ingest)
Temperature	°C	°F	°F, K
Temperature difference	Δ°C	Δ°F	Δ°F
Temperature rate	Δ°C/h	Δ°F/h	Δ°F/h
Air pressure	Pa	inH₂O	kPa, inH2O, psi, bar
Water pressure	Pa	psi	kPa, inH2O, psi, bar
Air flow	L/s	cfm	m³/s, m³/h, cfm, gpm
Water flow	L/s	gpm	m³/s, m³/h, cfm, gpm
Power	kW	kW	W, MW, Btu/h, ton, hp
Energy	kWh	kWh	Wh, MWh, kBtu, MMBtu, therm
Relative humidity	%	%	% (the SI unit only)
Concentration	ppm	ppm	none
Command or position	fraction, 0-1	%	`%`, ratio
Status	0/1	0/1	`bool`

Rules by equipment

Air handling units (34): AHU-DUCTHI · AHU-SATDEV · AHU-SIMUL · CMD-1 · DMP-1 · ECON-1 · ECON-2 · ECON-3 · ECON-4 · ECON-5 · ECON-6 · ECON-7 · FC1 · FC10 · FC11 · FC12 · FC13-SAT-HIGH · FC14 · FC15 · FC2 · FC3 · FC4 · FC5 · FC6 · FC7 · FC8 · FC9 · MECH-OAT-1 · OA-1 · RESET-1 · SCHED-1 · SCHED-247 · TRIM-1 · VLV-1

VAV terminals (9): VAV-1 · VAV-2 · VAV-3 · VAV-4 · VAV-5 · VAV-6 · VAV-7 · VAV-AHU-LEAVE · VAV-REHEAT

Fan coil and zone equipment (9): FCU-CLG-COIL · FCU-CO2-DAMPER · FCU-DAMPER-POS · FCU-DEADBAND · FCU-HTG-COIL · FCU-MODE-CYCLE · FCU-SENSOR-NULL · FCU-VALVE-PASS-CLG · FCU-VALVE-PASS-HTG

Chillers and plants (9): CHW-1 · CHW-2 · CHW-3 · CHW-4 · CHW-NOLOAD-1 · CW-APR-1 · CW-FAN-1 · CW-OPT-1 · TRIM-4

Boilers (1): TRIM-3

Heat pumps (1): HP-1

Meters and utilities (2): UTIL-INTERVAL · UTIL-MONTHLY

Sensor validation and control loops (6): PID-HUNT-1 · SV-FLATLINE · SV-RANGE · SV-RATE · SV-SPIKE · SV-STALE

Weather (2): OAT-METEO · WX-1

General (4): AVG-ZONE-TEMP · FAN-RUNTIME-HOURS · FAULT-ELAPSED-HOURS · ZONE-COMFORT-PCT

Air handling units

AHU / RTU / MAU / DOAS: duct static, supply air, economizer, mixing and mode faults.

AHU-DUCTHI

Duct static > static SP + margin.

Duct static pressure high · Family ahu · Equipment ahu · Confirm 5 min · function ahu_duct_high · SQL entry

Equation: Duct static > static SP + margin. Evaluates when fan is proven on OR duct static itself exceeds pressure_on_min (catches high static with fan-status off).

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`duct_static`	`duct-static-pressure`	Pressure	Pa	kPa, inH2O, psi, bar	-248.84 to 1990.72	required
`duct_static_sp`	`duct-static-pressure-sp`	Pressure	Pa	kPa, inH2O, psi, bar	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`duct_high_margin`	High margin	62.21	12.442	248.84	Pa
`pressure_on_min`	Pressure-on evidence	49.768	12.442	248.84	Pa

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

AHU-SATDEV

SAT − SAT SP

> 2.8 Δ°C.

SAT deviation from setpoint · Family ahu · Equipment ahu · Confirm 10 min · function ahu_sat_dev · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`sat_sp`	`discharge-air-temp-sp`	Temperature	°C	°F, K	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`sat_dev_err`	SAT deviation	2.77778	0.555556	8.33333	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL and pandas gate ‘equipment on’ with different fan/pump proof order and thresholds

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

AHU-SIMUL

Heating valve > 10% AND cooling valve > 10% at once.

Heating and cooling simultaneous · Family ahu · Equipment ahu · Confirm 5 min · function ahu_simul_heat_cool · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`valve_open_pct`	Valve open threshold	0.1	0.05	0.5	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

CMD-1

Fan command and proven status disagree.

Fan cmd/status mismatch · Family ahu · Equipment ahu · Confirm 10 min · function cmd1 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

DMP-1

Damper ≤ 5% but MAT tracks OAT within 1.1 Δ°C — leaking OA damper.

OA damper leakage · Family ahu · Equipment ahu · Confirm 15 min · function dmp1 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`leak_delta`	Leak ΔT	1.11111	0.277778	3.33333	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

ECON-1

Fan on, OA damper < 5%, OAT > 12.8 °C (should be economizing).

Economizer stuck closed · Family ahu · Equipment ahu · Confirm 10 min · function econ1 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`econ1_oat_min`	Favorable OAT	12.7778	7.22222	21.1111	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

ECON-2

OAT > 17.2 °C AND OA damper > 42% (should be at minimum).

Economizing when outdoor unfavorable · Family ahu · Equipment ahu · Confirm 5 min · function econ2 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`econ2_damper`	Damper open frac	0.42	0.2	0.9	fraction (0-1)
`econ2_oat_hi`	OAT high cutoff	17.2222	12.7778	26.6667	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

ECON-3

Flags mechanical cooling during web free-cool weather when the OA damper is not fully integrated.

Mech cooling without integrated economizer · Family ahu · Equipment ahu · Confirm 5 min · function econ2 · SQL entry

Equation: Web free-cooling opportunity: 15.6 °C ≤ dry-bulb < 22.2 °C AND dewpoint < 15.6 °C (dewpoint from web sensor or calculated from web DB+RH). Fault when cooling valve is open while OA damper is below the integrated-economizer threshold (default 90%). No BAS OAT fallback. Screenable engineering defaults — not code limits.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required
`web_oa_t`	`web-outside-air-temp`	Temperature	°C	°F, K	-	optional
`web_oa_dp`	`web-outside-air-dewpoint`	Temperature	°C	°F, K	-	optional
`web_oa_h`	`web-outside-air-humidity`	Relative humidity	%RH (0-100)	none	0 to 100	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`econ3_damper_hi`	Integrated economizer damper	0.9	0.5	1	fraction (0-1)
`econ3_db_max`	Free-cool OA dry-bulb max	22.2222	18.3333	26.6667	°C
`econ3_db_min`	Free-cool OA dry-bulb min	15.5556	10	20	°C
`econ3_dp_max`	Free-cool OA dew point max	15.5556	7.22222	20	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: weather source: SQL prefers equipment web_oa_* then as-of weather rows; pandas resolves its own web columns

ECON-4

Fan on,

RAT−OAT

> 1.2 Δ°C, estimated OA fraction < 21%.

Low estimated OA fraction · Family ahu · Equipment ahu · Confirm 10 min · function econ4 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`rat`	`return-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`oa_min_pct`	Min OA fraction	21	5	40	%

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL holds the fan-restart / mode-delay window over rolling rows, pandas GL36 suppresses after a mode change: differs by a few samples at fault edges

ECON-5

Preheat leaving air > 1.2°C above target while preheat active.

Preheat over-conditioning · Family ahu · Equipment ahu · Confirm 10 min · function econ5 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`preheat_leave_t`	`preheat-leaving-temp`	Temperature	°C	°F, K	-	required
`sat_sp`	`discharge-air-temp-sp`	Temperature	°C	°F, K	-	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`preheat_over`	Preheat over ΔT	1.22222	0.277778	4.44444	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

ECON-6

Flags an AHU economizing above min-OA when web outdoor air is below freezing (−3.9 °C).

Economizing in freezing weather · Family ahu · Equipment ahu · Confirm 10 min · function econ6_compute · SQL entry

Equation: Web dry-bulb < −3.9°C AND OA damper above winter min-OA ceiling (default 25%). AHU should be at minimum OA in cold weather.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`web_oa_t`	`web-outside-air-temp`	Temperature	°C	°F, K	-	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`econ6_damper_max`	Winter min-OA damper	0.25	0.05	0.5	fraction (0-1)
`econ6_oat_max`	Winter OAT ceiling	-3.88889	-9.44444	4.44444	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

ECON-7

Flags cooling demand during economizer-OK web weather (dew point < 15.6 °C, dry-bulb < 22.2 °C) while the OA damper is not economizing.

Economizer OK but not economizing · Family ahu · Equipment ahu · Confirm 10 min · function econ7_compute · SQL entry

Equation: Economizer-OK web weather: dew point < 15.6°C AND dry-bulb < 22.2°C (above a 1.7°C freeze-guard floor; dewpoint from web sensor or calculated from web DB+RH). Fault when there is cooling demand (cooling valve open or proven DX/chiller cooling) but the OA damper stays below the economizing threshold (default 50%). Expected: economizer-only below 15.6°C DB (MECH-OAT-1) and mech + integrated economizer in the 15.6–22.2°C band (ECON-3). All temperature thresholds are SI.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`web_oa_t`	`web-outside-air-temp`	Temperature	°C	°F, K	-	optional
`web_oa_dp`	`web-outside-air-dewpoint`	Temperature	°C	°F, K	-	optional
`web_oa_h`	`web-outside-air-humidity`	Relative humidity	%RH (0-100)	none	0 to 100	optional
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	optional
`compressor_status`	`compressor-status`	Status	0/1	bool	0 or 1	optional
-	`dx-cool-cmd`	Command or position	0-1	%, ratio	0 to 1	optional (pandas only)

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`econ7_damper_min`	Economizing damper threshold	0.5	0.2	0.9	fraction (0-1)
`econ7_db_max`	Econ-OK dry-bulb max	22.2222	18.3333	26.6667	°C
`econ7_db_min`	Econ-OK dry-bulb floor (freeze guard)	1.66667	-6.66667	10	°C
`econ7_dp_max`	Econ-OK dew point max	15.5556	7.22222	20	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: weather source: SQL prefers equipment web_oa_* then as-of weather rows; pandas resolves its own web columns

FC1

Flags duct static too low while the supply fan is near full speed.

Duct static below SP at full fan (GL36 A) · Family ahu · Equipment ahu · Confirm 5 min · function fc1 · SQL entry

Equation: DSP < DSPSP − εDSP AND VFDSPD ≥ 100% − εVFDSPD.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`duct_static`	`duct-static-pressure`	Pressure	Pa	kPa, inH2O, psi, bar	-248.84 to 1990.72	required
`duct_static_sp`	`duct-static-pressure-sp`	Pressure	Pa	kPa, inH2O, psi, bar	-	required
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`duct_static_err`	Legacy duct-static error (sets εDSP)	29.8608	0	124.42	Pa
`eps_dsp`	Duct-static error εDSP	29.8608	0	124.42	Pa
`eps_vfd_spd`	VFD speed error εVFDSPD (GL36 default 5%)	0.13	0	0.5	fraction (0-1)
`fan_hi`	Legacy fan-high threshold (sets εVFDSPD)	0.87	0.5	1	fraction (0-1)
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

FC10

MATavg − OATavg

> √(εMAT² + εOAT²) in OS#3.

OAT/MAT mismatch + mech cooling (GL36 H) · Family ahu · Equipment ahu · Confirm 10 min · function fc10 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`clg_on_min`	Cooling-command ON threshold	0.01	0	0.25	fraction (0-1)
`confirm_min`	Fault confirm delay	10	0	60	min
`econ_full_open`	Economizer full-open threshold	0.9	0.5	1	fraction (0-1)
`eps_mat`	MAT sensor error εMAT	0.638889	0	5.55556	Δ°C
`eps_oat`	OAT sensor error εOAT	0.638889	0	5.55556	Δ°C
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	0	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC11

OATavg + εOAT < SATSP − ΔTSF − εSAT in OS#3.

OAT/MAT mismatch economizer-only (GL36 I) · Family ahu · Equipment ahu · Confirm 10 min · function fc11 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`sat_sp`	`discharge-air-temp-sp`	Temperature	°C	°F, K	-	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`clg_on_min`	Cooling-command ON threshold	0.01	0	0.25	fraction (0-1)
`confirm_min`	Fault confirm delay	10	0	60	min
`delta_supply_fan`	Supply-fan heat rise ΔTSF	0.305556	0	2.77778	Δ°C
`econ_full_open`	Economizer full-open threshold	0.9	0.5	1	fraction (0-1)
`eps_oat`	OAT sensor error εOAT	0.638889	0	5.55556	Δ°C
`eps_sat`	SAT sensor error εSAT	0.638889	0	5.55556	Δ°C
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	0	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC12

SATavg − εSAT − ΔTSF ≥ MATavg + εMAT in OS#3/OS#4.

SAT above blend in cooling (GL36 J) · Family ahu · Equipment ahu · Confirm 10 min · function fc12 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`clg_on_min`	Cooling-command ON threshold	0.01	0	0.25	fraction (0-1)
`confirm_min`	Fault confirm delay	10	0	60	min
`delta_supply_fan`	Supply-fan heat rise ΔTSF	0.305556	0	2.77778	Δ°C
`econ_full_open`	Economizer full-open threshold	0.9	0.5	1	fraction (0-1)
`econ_min_pos`	Economizer minimum-position threshold	0.05	0	0.5	fraction (0-1)
`eps_mat`	MAT sensor error εMAT	0.638889	0	5.55556	Δ°C
`eps_sat`	SAT sensor error εSAT	0.638889	0	5.55556	Δ°C
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	0	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min
`supply_tol`	Legacy SAT tolerance master (sets εSAT)	0.638889	0	5.55556	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC13-SAT-HIGH

SATavg > SATSP + εSAT AND CC ≥ full-cooling threshold in OS#3/OS#4.

SAT above SP at full cooling (GL36 K) · Family ahu · Equipment ahu · Confirm 10 min · function fc13 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`sat_sp`	`discharge-air-temp-sp`	Temperature	°C	°F, K	-	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`clg_full_min`	Full-cooling threshold (GL36 99%)	0.01	0.5	1	fraction (0-1)
`confirm_min`	Fault confirm delay	10	0	60	min
`econ_full_open`	Economizer full-open threshold	0.9	0.5	1	fraction (0-1)
`econ_min_pos`	Economizer minimum-position threshold	0.05	0	0.5	fraction (0-1)
`eps_sat`	SAT sensor error εSAT	0.638889	0	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min
`sat_err`	Legacy SAT error (sets εSAT)	0.555556	0	5.55556	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL and pandas gate ‘equipment on’ with different fan/pump proof order and thresholds

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC14

Cooling-coil ΔT ≥ √(εCCET² + εCCLT²) + ΔTSF while coil should be inactive.

CHW coil ΔT when inactive (GL36 L) · Family ahu · Equipment ahu · Confirm 10 min · function fc14 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`cooling_coil_entering_temp`	`cooling-coil-entering-temp`	Temperature	°C	°F, K	-	required
`cooling_coil_leaving_temp`	`cooling-coil-leaving-temp`	Temperature	°C	°F, K	-	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Max	SI unit
`clg_inactive_max`	Cooling-command inactive ceiling	0.1	0.5	fraction (0-1)
`confirm_min`	Fault confirm delay	10	60	min
`delta_supply_fan`	Supply-fan heat rise ΔTSF	0.305556	2.77778	Δ°C
`econ_min_pos`	Economizer minimum-position threshold	0.05	0.5	fraction (0-1)
`eps_ccet`	Cooling-coil entering sensor error εCCET	0.638889	5.55556	Δ°C
`eps_cclt`	Cooling-coil leaving sensor error εCCLT	0.638889	5.55556	Δ°C
`htg_on_min`	Heating-command ON threshold	0.01	0.25	fraction (0-1)
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL and pandas gate ‘equipment on’ with different fan/pump proof order and thresholds

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC15

Heating-coil ΔT ≥ √(εHCET² + εHCLT²) + ΔTSF while coil should be inactive.

HW coil ΔT when inactive (GL36 M) · Family ahu · Equipment ahu · Confirm 10 min · function fc15 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`heating_coil_entering_temp`	`heating-coil-entering-temp`	Temperature	°C	°F, K	-	required
`heating_coil_leaving_temp`	`heating-coil-leaving-temp`	Temperature	°C	°F, K	-	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`clg_inactive_max`	Cooling-command inactive ceiling	0.1	0	0.5	fraction (0-1)
`clg_on_min`	Cooling-command ON threshold	0.01	0	0.25	fraction (0-1)
`confirm_min`	Fault confirm delay	10	0	60	min
`delta_supply_fan`	Supply-fan heat rise ΔTSF	0.305556	0	2.77778	Δ°C
`econ_full_open`	Economizer full-open threshold	0.9	0.5	1	fraction (0-1)
`econ_min_pos`	Economizer minimum-position threshold	0.05	0	0.5	fraction (0-1)
`eps_hcet`	Heating-coil entering sensor error εHCET	0.638889	0	5.55556	Δ°C
`eps_hclt`	Heating-coil leaving sensor error εHCLT	0.638889	0	5.55556	Δ°C
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	0	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC2

Flags mixed-air temperature colder than the OAT/RAT mixing envelope allows.

MAT below OAT/RAT envelope (GL36 B) · Family ahu · Equipment ahu · Confirm 10 min · function fc2 · SQL entry

Equation: MATavg + εMAT < min(RATavg − εRAT, OATavg − εOAT).

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`rat`	`return-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Max	SI unit
`confirm_min`	Fault confirm delay	10	60	min
`eps_mat`	MAT sensor error εMAT	0.638889	5.55556	Δ°C
`eps_oat`	OAT sensor error εOAT	0.638889	5.55556	Δ°C
`eps_rat`	RAT sensor error εRAT	0.638889	5.55556	Δ°C
`fan_on_min`	Fan-on command threshold	0.01	0.25	fraction (0-1)
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC3

Flags mixed-air temperature warmer than the OAT/RAT mixing envelope allows.

MAT above OAT/RAT envelope (GL36 C) · Family ahu · Equipment ahu · Confirm 10 min · function fc3 · SQL entry

Equation: MATavg − εMAT > max(RATavg + εRAT, OATavg + εOAT).

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`rat`	`return-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Max	SI unit
`confirm_min`	Fault confirm delay	10	60	min
`eps_mat`	MAT sensor error εMAT	0.638889	5.55556	Δ°C
`eps_oat`	OAT sensor error εOAT	0.638889	5.55556	Δ°C
`eps_rat`	RAT sensor error εRAT	0.638889	5.55556	Δ°C
`fan_on_min`	Fan-on command threshold	0.01	0.25	fraction (0-1)
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on edge data: Same cause as FC8: the series begins with the fan already running (edge DST-week start is 18:00 local); pandas applies its 600 s operational startup holdoff at the first sample, SQL does not (verified by trimming the first 6 h of rows).

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC4

ΔOS > ΔOSmax during the prior 60-minute moving window.

PID hunting (operating-state oscillation) · Family ahu · Equipment ahu · Confirm 60 min · function fc4 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	60	0	60	min
`delta_os_max`	Max mode changes/hr ΔOSmax (GL36 default 7)	5	1	30	count
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

FC5

SATavg + εSAT ≤ MATavg − εMAT + ΔTSF while heating is commanded.

SAT cold when heating commanded (GL36 D) · Family ahu · Equipment ahu · Confirm 10 min · function fc5 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Max	SI unit
`confirm_min`	Fault confirm delay	10	60	min
`delta_supply_fan`	Supply-fan heat rise ΔTSF	0.305556	2.77778	Δ°C
`eps_mat`	MAT sensor error εMAT	0.638889	5.55556	Δ°C
`eps_sat`	SAT sensor error εSAT	0.638889	5.55556	Δ°C
`fan_on_min`	Fan-on command threshold	0.01	0.25	fraction (0-1)
`htg_on_min`	Heating-command ON threshold	0.01	0.25	fraction (0-1)
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL holds the fan-restart / mode-delay window over rolling rows, pandas GL36 suppresses after a mode change: differs by a few samples at fault edges

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC6

RATavg−OATavg

≥ ΔTmin AND

estimated OA% − design min OA%

> εF.

Estimated OA fraction mismatch · Family ahu · Equipment ahu · Confirm 10 min · function fc6 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`rat`	`return-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`vav_total_flow`	`vav-total-airflow`	Flow	L/s	m³/s, m³/h, cfm, gpm	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`airflow_err`	Legacy OA-fraction error (sets εF)	0.15	0.05	1	fraction (0-1)
`confirm_min`	Fault confirm delay	10	0	60	min
`delta_t_min`	Minimum \|OAT−RAT\| ΔTmin	2.77778	0	16.6667	Δ°C
`eps_airflow`	Airflow error εF (GL36 default 30%)	0.15	0.05	1	fraction (0-1)
`fan_on_min`	Fan-on command threshold	0.01	0	0.25	fraction (0-1)
`min_flow_design`	Design minimum outdoor airflow	2359.74	0	94389.4	L/s
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min
`oat_rat_delta_min`	Legacy OAT/RAT guard (sets ΔTmin)	2.77778	0	16.6667	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL and pandas gate ‘equipment on’ with different fan/pump proof order and thresholds

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC7

SATavg < SATSP − εSAT AND HC ≥ full-heating threshold.

SAT low with full heating (GL36 E) · Family ahu · Equipment ahu · Confirm 10 min · function fc7 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`sat_sp`	`discharge-air-temp-sp`	Temperature	°C	°F, K	-	required
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`eps_sat`	SAT sensor error εSAT	0.638889	0	5.55556	Δ°C
`fan_on_min`	Fan-on command threshold	0.01	0	0.25	fraction (0-1)
`htg_full_min`	Full-heating threshold (GL36 99%)	0.9	0.5	1	fraction (0-1)
`mode_delay_min`	Mode-change suspension (product default)	10	0	60	min
`sat_err`	Legacy SAT error (sets εSAT)	0.555556	0	5.55556	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL and pandas gate ‘equipment on’ with different fan/pump proof order and thresholds

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC8

SATavg − ΔTSF − MATavg

> √(εSAT² + εMAT²) in OS#2.

SAT/MAT mismatch in economizer (GL36) · Family ahu · Equipment ahu · Confirm 10 min · function fc8 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Max	SI unit
`clg_inactive_max`	Cooling-command inactive ceiling	0.1	0.5	fraction (0-1)
`confirm_min`	Fault confirm delay	10	60	min
`delta_supply_fan`	Supply-fan heat rise ΔTSF	0.305556	2.77778	Δ°C
`econ_min_pos`	Economizer minimum-position threshold	0.05	0.5	fraction (0-1)
`eps_mat`	MAT sensor error εMAT	0.638889	5.55556	Δ°C
`eps_sat`	SAT sensor error εSAT	0.638889	5.55556	Δ°C
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	60	min
`supply_tol`	Legacy SAT tolerance master (sets εSAT)	0.638889	5.55556	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on edge data: Series starts with the fan already running (edge DST-week start is 18:00 local): pandas applies its 600 s operational startup holdoff at the first sample, SQL has none, so SQL confirms one 5-minute sample earlier. Verified: trimming the first 6 h of rows makes SQL equal pandas.

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

FC9

OATavg − εOAT > SATSP − ΔTSF + εSAT in OS#2.

OAT too warm for free cooling (GL36 G) · Family ahu · Equipment ahu · Confirm 10 min · function fc9 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`sat_sp`	`discharge-air-temp-sp`	Temperature	°C	°F, K	-	required
`oa_damper_pct`	`outside-air-damper`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Max	SI unit
`clg_inactive_max`	Cooling-command inactive ceiling	0.1	0.5	fraction (0-1)
`confirm_min`	Fault confirm delay	10	60	min
`delta_supply_fan`	Supply-fan heat rise ΔTSF	0.305556	2.77778	Δ°C
`econ_min_pos`	Economizer minimum-position threshold	0.05	0.5	fraction (0-1)
`eps_oat`	OAT sensor error εOAT	0.638889	5.55556	Δ°C
`eps_sat`	SAT sensor error εSAT	0.638889	5.55556	Δ°C
`mix_tol`	Legacy master sensor tolerance (sets all ε values)	0.638889	5.55556	Δ°C
`mode_delay_min`	Mode-change suspension (product default)	10	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on edge data: Same cause as FC8: the series begins with the fan already running; pandas holds off 600 s from the first sample, SQL does not (verified by trimming the start).

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

MECH-OAT-1

Flags proven DX or chiller cooling while web dry-bulb is below 15.6 °C.

Mechanical cooling below 15.6 °C web OAT · Family ahu · Equipment ahu, chiller, heatpump · Confirm 10 min · function mech_oat1_compute · SQL entry

Equation: Proven DX/chiller mechanical cooling while web dry-bulb < 15.6 °C. Uses compressor/chiller/pump/amps/power proof — not AHU cooling-valve alone. Below 15.6 °C is outside the free-cool + integrated economizer band.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`web_oa_t`	`web-outside-air-temp`	Temperature	°C	°F, K	-	optional
`compressor_status`	`compressor-status`	Status	0/1	bool	0 or 1	optional
`chiller_status`	`chiller-status`	Status	0/1	bool	0 or 1	optional
`chw_pump_status`	`chw-pump-status`	Status	0/1	bool	0 or 1	optional
-	`dx-cool-cmd`	Command or position	0-1	%, ratio	0 to 1	optional (pandas only)

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`mech_oat_max`	Mech-cool OAT ceiling	15.5556	7.22222	18.3333	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: pandas proves equipment/cooling from typed roles (mechanical_proof_mask, equipment_type); SQL ORs chiller status / valve

OA-1

Estimated OA fraction < 15% with adequate OAT/RAT split.

Low OA fraction · Family ahu · Equipment ahu · Confirm 15 min · function oa1 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	required
`rat`	`return-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`min_oa_frac`	Min OA fraction	0.15	0.05	0.4	fraction (0-1)
`oat_rat_guard`	Min \|RAT−OAT\| guard	1.22222	0.277778	3.33333	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL holds the fan-restart / mode-delay window over rolling rows, pandas GL36 suppresses after a mode change: differs by a few samples at fault edges

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

RESET-1

Flags SAT setpoint that is not tracking the outdoor-air reset curve.

SAT reset not tracking outdoor air · Family ahu · Equipment ahu · Confirm 15 min · function reset1 · SQL entry

Equation: Fan on AND

SAT SP − (11.1 + 0.25×(OAT−18.3))

> 1.7 Δ°C.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat_sp`	`discharge-air-temp-sp`	Temperature	°C	°F, K	-	required
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`reset_err`	Reset error	1.66667	0.277778	5.55556	Δ°C
`reset_oat_ref`	Reset OAT ref	18.3333	10	26.6667	°C
`reset_sat_at_ref`	SAT SP at the reset OAT reference	11.1111	7.22222	18.3333	°C
`reset_slope`	Reset slope	0.25	0.05	1	Δ°C/Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

SCHED-1

Flags fan runtime during unoccupied hours from the Overview calendar.

Unoccupied runtime · Family schedule · Equipment ahu · Confirm 30 min · function sched1 · SQL entry

Equation: Fan running while occupancy is unoccupied (Overview calendar → occ_mode). When zone_t is mapped, also require zone inside comfort_low…comfort_high (defaults 21.1–23.9 °C; synced from Overview zone band).

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`occ_mode`	`occupied`	Text	text	none	-	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	required
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`comfort_high`	Comfort high	23.8889	12.7778	32.2222	°C
`comfort_low`	Comfort low	21.1111	10	26.6667	°C
`confirm_min`	Fault confirm delay	30	0	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

SCHED-247

Flags fans or pumps that stay on for nearly the entire analysis window (24/7 runtime).

Always-on fan or pump runtime · Family schedule · Equipment ahu, vav, chiller, boiler, heatpump · Confirm 60 min · function _sched247 · SQL entry

Equation: Ranked proof (status/current > command) is on for ≥ always_on_pct of the window. Pressure is inferred runtime only and does not trip this rule ID.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`pump_status`	`pump-status`	Status	0/1	bool	0 or 1	optional
`chw_pump_status`	`chw-pump-status`	Status	0/1	bool	0 or 1	optional
-	`hw-pump-status`	Status	0/1	bool	0 or 1	optional (pandas only)
`chiller_status`	`chiller-status`	Status	0/1	bool	0 or 1	optional
`compressor_status`	`compressor-status`	Status	0/1	bool	0 or 1	optional
`tower_fan_cmd`	`tower-fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`tower_fan_cmd`	`tower-fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`chw_pump_cmd`	`chw-pump-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
-	`hw-pump-cmd`	Command or position	0-1	%, ratio	0 to 1	optional (pandas only)
`duct_static`	`duct-static-pressure`	Pressure	Pa	kPa, inH2O, psi, bar	-248.84 to 1990.72	optional
`chw_dp`	`chw-diff-pressure`	Pressure	Pa	kPa, inH2O, psi, bar	-6894.76 to 689476	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`always_on_pct`	Always-on fraction	0.95	0.8	1	fraction (0-1)
`confirm_min`	Fault confirm delay	60	0	60	min
`pressure_on_min`	Pressure-on evidence	49.768	12.442	497.68	Pa

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

TRIM-1

Duct static high (> 336 Pa) while VAV pressure requests are low.

Duct static trim advisory · Family trim · Equipment ahu · Confirm 30 min · function trim1 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`duct_static`	`duct-static-pressure`	Pressure	Pa	kPa, inH2O, psi, bar	-248.84 to 1990.72	required
`static_reset_request`	`vav-pressure-request-sum`	Count	count	none	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	30	0	60	min
`duct_hi`	Duct static high	335.934	124.42	746.52	Pa
`request_lo`	Request sum low	1	0	10	count

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL and pandas gate ‘equipment on’ with different fan/pump proof order and thresholds

VLV-1

Flags a closed cooling valve while SAT still looks like valve leakage.

Cooling valve leakage · Family ahu · Equipment ahu · Confirm 15 min · function vlv1 · SQL entry

Equation: Cooling valve ≤ 5% AND (SAT < sat_sp − sat_err OR SAT < MAT − mat_leak_delta). Fan proven on when fan_status/fan_cmd present (operational gate).

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`sat_sp`	`discharge-air-temp-sp`	Temperature	°C	°F, K	-	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required
`mat`	`mixed-air-temp`	Temperature	°C	°F, K	-28.89 to 43.33	optional
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`mat_leak_delta`	SAT vs MAT leak ΔT	1.11111	0.277778	6.66667	Δ°C
`sat_err`	SAT vs SP leak ΔT	1.11111	0.277778	4.44444	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

VAV terminals

VAV boxes and other zone terminals: comfort, airflow, reheat and damper faults.

VAV-1

Flags occupied-band zone temperature violations.

Zone comfort band · Family vav · Equipment vav, zone_other, heatpump, baseboard · Confirm 15 min · function vav1 · SQL entry

Equation: Zone temp outside zone_lo–zone_hi (default 21.1–23.9 °C) during occupied hours when an occupancy column or Overview calendar is set (require_occupied, default on). Unoccupied setback stays on VAV-2.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`occ_mode`	`occupied`	Text	text	none	-	optional
`occ_mode`	`occupied`	Text	text	none	-	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`require_occupied`	Require occupied	1	0	1	0/1
`zone_hi`	Zone high	23.8889	22.2222	29.4444	°C
`zone_lo`	Zone low	21.1111	12.7778	22.2222	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on edge data: Two input-handling differences: (1) NULL zone_t cells: SQL drops NULL rows (WHERE zone_t IS NOT NULL) and holds the previous sample’s state across the null run, pandas scores a NULL as not faulted; (2) planted out-of-range zone_t (80 degC): the pandas quality layer marks it OUT_OF_RANGE and excludes it, SQL scores the value as given.

VAV-2

Flags unoccupied zones that never drop into heating setback.

Night setback miss · Family vav · Equipment vav, zone_other, heatpump, baseboard · Confirm 15 min · function vav2 · SQL entry

Equation: Unoccupied AND zone temp > setback_hi (default 20 °C) — heating setback not taken.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`occ_mode`	`occupied`	Text	text	none	-	required
`occ_mode`	`occupied`	Text	text	none	-	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`setback_hi`	Setback high	20	12.7778	22.2222	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

VAV-3

Air flowing AND OAT > 25.6 °C AND reheat valve > 52%.

Excessive reheat during warm weather · Family vav · Equipment vav · Confirm 5 min · function vav3 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`reheat_valve_pct`	`reheat-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`flow_on_min`	Airflow-on min	11.7987	0	94.3894	L/s
`reheat_oat`	Warm OAT	25.5556	18.3333	32.2222	°C
`reheat_pct`	Reheat frac	0.52	0.1	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

VAV-4

Air flowing AND damper > 97.5% sustained across the window.

Damper stuck at full open · Family vav · Equipment vav · Confirm 15 min · function vav4 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`damper_pct`	`damper`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`flow_on_min`	Airflow-on min	11.7987	0	94.3894	L/s
`full_open_pct`	Full open frac	0.975	0.8	1	fraction (0-1)
`sustain_hours`	Sustain window	1.5	0.5	6	h

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

VAV-5

Airflow > ~24 L/s while damper < 10% (implausible flow).

Airflow sensor bias · Family vav · Equipment vav · Confirm 15 min · function vav5 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`zone_flow`	`zone-airflow`	Flow	L/s	m³/s, m³/h, cfm, gpm	-	required
`damper_pct`	`damper`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

VAV-6

Flags reheat while outdoor air is cool enough for free cooling.

Reheat when cooling available · Family vav · Equipment vav · Confirm 15 min · function vav6 · SQL entry

Equation: OAT < 18.3 °C AND reheat valve > 25% (optional cooling-available must be true when mapped).

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`reheat_valve_pct`	`reheat-valve`	Command or position	0-1	%, ratio	0 to 1	required
`clg_available`	`clg-available`	Status	0/1	bool	0 or 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`free_cool_oat`	Free-cool OAT	18.3333	7.22222	23.8889	°C
`reheat_pct`	Reheat frac	0.25	0.05	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL holds the fan-restart / mode-delay window over rolling rows, pandas GL36 suppresses after a mode change: differs by a few samples at fault edges

VAV-7

Flow below min SP (when mapped), OR airflow stays flat (low rolling std) at a high mean while air is on (mins too high / box never modulates), OR min_flow_sp itself is excessively high.

Min airflow / fixed high flow · Family vav · Equipment vav · Confirm 15 min · function vav7 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`zone_flow`	`zone-airflow`	Flow	L/s	m³/s, m³/h, cfm, gpm	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`fixed_flow_max_std`	Fixed-flow max std	7.0792	0.471947	37.7558	L/s
`fixed_flow_min_mean`	Fixed-flow min mean	94.3894	23.5973	943.894	L/s
`flow_on_min`	Airflow-on min	11.7987	0	94.3894	L/s
`high_min_flow_sp`	High min-flow SP	117.987	23.5973	943.894	L/s

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on edge data: Duplicate (equipment, timestamp) rows: SQL scores the rows as delivered, the reference de-duplicates first (the input contract is one row per timestamp). Verified: de-duplicating the rows before SQL makes SQL equal pandas.

VAV-AHU-LEAVE

Flags VAV discharge far from the parent AHU SAT when topology feeds are known.

VAV leave vs parent AHU SAT (fedBy) · Family vav · Equipment vav · Confirm 15 min · function vav_vs_ahu_leave · SQL entry

Equation: Air flowing AND

VAV discharge − parent AHU SAT

> band. Needs package topology (vav_to_ahu) so ahu_sat is enriched from the fedBy AHU; otherwise SKIPPED_MISSING_ROLES. Flags broken reheat, bad sensors, or rogue zones.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`vav_discharge_t`	`vav-discharge-air-temp`	Temperature	°C	°F, K	-	required
`ahu_sat`	`ahu-discharge-air-temp`	Temperature	°C	°F, K	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`delta`	Leave Δ vs AHU SAT	4.44444	1.11111	13.8889	°C
`flow_on_min`	Airflow-on min	11.7987	0	94.3894	L/s

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL holds the fan-restart / mode-delay window over rolling rows, pandas GL36 suppresses after a mode change: differs by a few samples at fault edges

VAV-REHEAT

Flags reheat commanded open with airflow but almost no discharge temperature rise.

Reheat valve stuck / no temp rise · Family vav · Equipment vav · Confirm 15 min · function vav_reheat_stuck · SQL entry

Equation: Air flowing AND reheat valve > 30% AND box discharge temp rises < 1.7 °C above duct inlet (air from AHU) — stuck or failed reheat valve/coil.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`reheat_valve_pct`	`reheat-valve`	Command or position	0-1	%, ratio	0 to 1	required
`vav_discharge_t`	`vav-discharge-air-temp`	Temperature	°C	°F, K	-	required
`vav_inlet_t`	`vav-inlet-air-temp`	Temperature	°C	°F, K	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`flow_on_min`	Airflow-on min	11.7987	0	94.3894	L/s
`min_rise`	Min temp rise	1.66667	0.277778	8.33333	°C
`reheat_cmd`	Reheat open frac	0.3	0.1	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on stress-only data: pandas operational gate holds a fan-running rule for startup_delay_seconds=600 after the fan proves on, SQL has no startup holdoff: a fault already present at fan start is confirmed one 5-minute sample earlier in SQL per fan start (0.1667 h over the two fan starts of the 8-equipment 7-day run); with the gate off pandas equals SQL

Fan coil and zone equipment

Fan coils, unit ventilators and other zone_other equipment.

FCU-CLG-COIL

Fan on, cooling valve ≥80%, and heating shut, but discharge air is not below zone temperature.

FCU cooling coil under-delivery · Family fcu · Equipment zone_other, general, ahu · Confirm 15 min · function fcu_clg_coil · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`valve_open`	Valve open threshold	0.8	0.5	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

FCU-CO2-DAMPER

Fan on and valid CO₂ exceeds 1000 ppm while damper command remains below 10%.

FCU high CO2 with low outdoor-air command · Family fcu · Equipment zone_other, general, ahu · Confirm 15 min · function fcu_co2_damper · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`zone_co2`	`zone-co2`	Concentration	ppm	none	-	required
`damper_cmd`	`damper-cmd`	Command or position	0-1	%, ratio	0 to 1	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`co2_high_ppm`	High CO₂	1000	600	2000	ppm
`confirm_min`	Fault confirm delay	15	0	60	min
`damper_low`	Low damper command	0.1	0	0.5	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

FCU-DAMPER-POS

Fan on and damper command ≥15%, but feedback is more than 15 percentage points below command.

FCU damper command/position mismatch · Family fcu · Equipment zone_other, general, ahu · Confirm 15 min · function fcu_damper_pos · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`damper_cmd`	`damper-cmd`	Command or position	0-1	%, ratio	0 to 1	required
`damper_pct`	`damper`	Command or position	0-1	%, ratio	0 to 1	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`command_min`	Minimum damper command	0.15	0	1	fraction (0-1)
`confirm_min`	Fault confirm delay	15	0	60	min
`position_error`	Position error	0.15	0.05	0.5	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

FCU-DEADBAND

Pass-through cooling setpoint minus heating setpoint is less than 1°C.

FCU heat/cool deadband collapse · Family fcu · Equipment zone_other, general, ahu · Confirm 0 min · function fcu_deadband · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`cooling_sp`	`cooling-sp`	Temperature	°C	°F, K	-	required
`heating_sp`	`heating-sp`	Temperature	°C	°F, K	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	0	0	60	min
`deadband`	Minimum deadband	1	0	5	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

FCU-HTG-COIL

Fan on and heating valve ≥80%, but discharge air is less than 3 Δ°C above zone temperature.

FCU heating coil under-delivery · Family fcu · Equipment zone_other, general, ahu · Confirm 15 min · function fcu_htg_coil · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`coil_delta`	Minimum heating rise	3	0.555556	11.1111	°C
`confirm_min`	Fault confirm delay	15	0	60	min
`valve_open`	Valve open threshold	0.8	0.5	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL and pandas gate ‘equipment on’ with different fan/pump proof order and thresholds

FCU-MODE-CYCLE

At least four heating/cooling valve mode changes occur in the analysis window.

FCU heating/cooling mode cycling · Family fcu · Equipment zone_other, general, ahu · Confirm 0 min · function fcu_mode_cycle · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	0	0	60	min
`mode_changes`	Mode changes	4	1	20	count
`mode_valve_min`	Active valve threshold	0.1	0	0.5	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL holds the fan-restart / mode-delay window over rolling rows, pandas GL36 suppresses after a mode change: differs by a few samples at fault edges

FCU-SENSOR-NULL

Own zone setpoint is present while zone temperature is null for at least 90% of the window.

Missing FCU zone sensor · Family fcu · Equipment zone_other, general, ahu · Confirm 0 min · function fcu_sensor_null · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`zone_air_temp_sp`	`zone-air-temp-sp`	Temperature	°C	°F, K	-	required
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	0	0	60	min
`null_fraction`	Null fraction	0.9	0.5	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

FCU-VALVE-PASS-CLG

Fan on and both valves shut, but zone temperature exceeds discharge air by more than 3 Δ°C.

FCU cooling valve passing · Family fcu · Equipment zone_other, general, ahu · Confirm 15 min · function fcu_valve_pass_clg · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`pass_delta`	Passing temperature drop	3	0.555556	11.1111	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on edge data: Planted out-of-range zone_t (80 degC): the pandas quality layer marks those samples OUT_OF_RANGE and excludes them, SQL computes zone_t - sat on the value as given and faults.

FCU-VALVE-PASS-HTG

Fan on and both valves shut, but discharge air exceeds zone temperature by more than 3 Δ°C.

FCU heating valve passing · Family fcu · Equipment zone_other, general, ahu · Confirm 15 min · function fcu_valve_pass_htg · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`htg_valve_pct`	`heating-valve`	Command or position	0-1	%, ratio	0 to 1	required
`clg_valve_pct`	`cooling-valve`	Command or position	0-1	%, ratio	0 to 1	required
`fan_status`	`fan-status`	Status	0/1	bool	0 or 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`pass_delta`	Passing temperature rise	3	0.555556	11.1111	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

Chillers and plants

Chillers, chilled water and condenser water plants, cooling towers.

CHW-1

Pump on AND (CHWR − CHWS) < 2.2 Δ°C.

Low chilled-water ΔT · Family plant · Equipment chiller · Confirm 15 min · function chw1 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`chw_supply_t`	`chilled-water-supply-temp`	Temperature	°C	°F, K	-1.11 to 26.67	required
`chw_return_t`	`chilled-water-return-temp`	Temperature	°C	°F, K	-1.11 to 32.22	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`min_dt`	Min ΔT	2.22222	0.555556	6.66667	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL holds the fan-restart / mode-delay window over rolling rows, pandas GL36 suppresses after a mode change: differs by a few samples at fault edges

CHW-2

Pump ≥ 87% AND CHW DP < DP SP − 2.2.

DP below SP at max pump speed · Family plant · Equipment chiller · Confirm 5 min · function chw2 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`chw_dp`	`chw-diff-pressure`	Pressure	Pa	kPa, inH2O, psi, bar	-6894.76 to 689476	required
`chw_dp_sp`	`chw-diff-pressure-sp`	Pressure	Pa	kPa, inH2O, psi, bar	-	required
`chw_pump_cmd`	`chw-pump-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`dp_margin`	DP margin	15168.5	3447.38	41368.5	Pa
`pump_hi`	Pump high-speed threshold	0.87	0.5	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

CHW-3

Pump on AND

CHWS − CHWS SP

> 1.2 Δ°C.

Plant supply temp outside deadband · Family plant · Equipment chiller · Confirm 5 min · function chw3 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`chw_supply_t`	`chilled-water-supply-temp`	Temperature	°C	°F, K	-1.11 to 26.67	required
`chw_supply_sp`	`chilled-water-supply-temp-sp`	Temperature	°C	°F, K	-	required
`chw_pump_cmd`	`chw-pump-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`sp_band`	SP band	1.22222	0.277778	3.33333	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

CHW-4

Pump ≥ 87% AND CHW flow > 69.4 L/s.

Flow high at max pump · Family plant · Equipment chiller · Confirm 5 min · function chw4 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`chw_flow`	`chw-flow`	Flow	L/s	m³/s, m³/h, cfm, gpm	-1 to 1500	required
`chw_pump_cmd`	`chw-pump-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`flow_hi`	Flow high	69.3992	12.618	189.271	L/s
`pump_hi`	Pump high-speed threshold	0.87	0.5	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

CHW-NOLOAD-1

Flags a chiller running while mapped zones or AHU SAT show the building is satisfied.

Chiller running with no building load · Family plant · Equipment chiller · Confirm 30 min · function chw_noload1_compute · SQL entry

Equation: Chiller/plant proven running while building load is satisfied: all mapped zones inside comfort band OR all mapped AHU SAT within sat_band of setpoint. Default confirm 30 min.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`chiller_status`	`chiller-status`	Status	0/1	bool	0 or 1	optional
`chw_pump_status`	`chw-pump-status`	Status	0/1	bool	0 or 1	optional
`compressor_status`	`compressor-status`	Status	0/1	bool	0 or 1	optional
`building_zone_load_satisfied`	`building-zone-load-satisfied`	Status	0/1	bool	0 or 1	optional
`building_ahu_load_satisfied`	`building-ahu-load-satisfied`	Status	0/1	bool	0 or 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`comfort_high`	Comfort high	23.8889	20	29.4444	°C
`comfort_low`	Comfort low	21.1111	15.5556	25.5556	°C
`confirm_min`	Fault confirm delay	30	0	60	min
`sat_band`	AHU SAT≈SP band	1.11111	0.277778	3.33333	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours
`status`	-	assessment status text

Parity known divergence: pandas proves equipment/cooling from typed roles (mechanical_proof_mask, equipment_type); SQL ORs chiller status / valve

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

CW-APR-1

Flags high CW–wet-bulb approach at full tower fan — sensor mismatch or tower degradation.

High CW approach at full tower fan · Family plant · Equipment chiller, cooling_tower · Confirm 15 min · function cw_apr · SQL entry

Equation: At full tower fan speed, leaving CW − web wet-bulb exceeds approach_max (default 4.44°C, typically 2.8–5.6°C). Suspect OA→wet-bulb / CW sensor mismatch or cooling-tower performance degradation.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`cw_supply_t`	`condenser-water-supply-temp`	Temperature	°C	°F, K	0 to 50	required
`tower_fan_cmd`	`tower-fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`tower_fan_cmd`	`tower-fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`web_wb_t`	`web-outside-air-wetbulb`	Temperature	°C	°F, K	-	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`approach_max`	Max approach at full fan	4.44444	2.77778	8.33333	°C
`confirm_min`	Fault confirm delay	15	0	60	min
`tower_fan_hi`	Tower fan full-speed threshold	0.95	0.8	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

CW-FAN-1

Flags full-speed tower fans while CW is well above theoretical WB+approach — excess fan energy.

Excess tower fan energy vs wet-bulb limit · Family plant · Equipment chiller, cooling_tower · Confirm 15 min · function cw_fan_excess · SQL entry

Equation: Tower fans at full speed while leaving CW is well above web wet-bulb + design approach (approach + excess_beyond). Fans are chasing a CW temp that is theoretically hard/impossible — excess fan energy.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`cw_supply_t`	`condenser-water-supply-temp`	Temperature	°C	°F, K	0 to 50	required
`tower_fan_cmd`	`tower-fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`tower_fan_cmd`	`tower-fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	optional
`web_wb_t`	`web-outside-air-wetbulb`	Temperature	°C	°F, K	-	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`cw_approach`	Design approach	3.88889	1.66667	8.33333	°C
`excess_beyond_approach`	Excess beyond approach	2.77778	1.11111	11.1111	°C
`tower_fan_hi`	Tower fan full-speed threshold	0.95	0.8	1	fraction (0-1)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

CW-OPT-1

Flags condenser water colder than wet-bulb + approach — tower over-cooling / not optimized.

Condenser water not optimized vs wet-bulb · Family plant · Equipment chiller, cooling_tower · Confirm 15 min · function cw_opt · SQL entry

Equation: CW supply significantly colder than web wet-bulb + design approach (Stull WB) — tower over-cooling / not optimized.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`cw_supply_t`	`condenser-water-supply-temp`	Temperature	°C	°F, K	0 to 50	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`cw_approach`	Design approach	3.88889	1.66667	8.33333	°C
`cw_slack`	Slack below target	1.11111	0.277778	3.33333	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

TRIM-4

CHW supply < 7.2 °C while the reset request sum is at or below request_lo.

CHW plant reset advisory · Family trim · Equipment chiller · Confirm 30 min · function trim4 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`chw_supply_t`	`chilled-water-supply-temp`	Temperature	°C	°F, K	-1.11 to 26.67	required
`chw_reset_request_sum`	`chilled-water-reset-request-sum`	Count	count	none	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`chw_lo`	CHWS low	7.22222	1.66667	12.7778	°C
`confirm_min`	Fault confirm delay	30	0	60	min
`request_lo`	Request sum low	1	0	10	count

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on stress-only data: role names, threshold and missing input are aligned (#1588: contract roles hot-water- / chilled-water-reset-request-sum, fault at request sum <= request_lo, an absent request sum is not assessed on either side). Residual: pandas applies its hydronic proof gate with the 600 s startup holdoff, SQL has no startup holdoff, so SQL confirms one 5-minute sample earlier per pump start; matches on the 2 x 3 and 4 x 3 datasets, differs on the 8 x 7 run

Boilers

Boiler plants.

TRIM-3

HW supply > 71.1 °C while the reset request sum is at or below request_lo.

HWST trim advisory · Family trim · Equipment boiler · Confirm 30 min · function trim3 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`hw_supply_t`	`hot-water-supply-temp`	Temperature	°C	°F, K	4.44 to 104.44	required
`hw_reset_request_sum`	`hot-water-reset-request-sum`	Count	count	none	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	30	0	60	min
`hwst_hi`	HWST high	71.1111	48.8889	93.3333	°C
`request_lo`	Request sum low	1	0	10	count

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Heat pumps

Heat pumps.

HP-1

Fan on, zone < 20.6 °C, discharge SAT < 29.4 °C.

Discharge cold when heating · Family heatpump · Equipment heatpump · Confirm 10 min · function hp1 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`sat`	`discharge-air-temp`	Temperature	°C	°F, K	-1.11 to 65.56	required
`zone_t`	`zone-air-temp`	Temperature	°C	°F, K	4.44 to 37.78	required
`fan_cmd`	`fan-cmd`	Command or position	0-1	%, ratio	0 to 1	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`min_sat`	Min heating SAT	29.4444	21.1111	43.3333	°C
`zone_cold`	Zone cold	20.5556	15.5556	22.2222	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: SQL and pandas gate ‘equipment on’ with different fan/pump proof order and thresholds

Meters and utilities

Energy and demand meters, utility bill analytics.

UTIL-INTERVAL

BAS 15m vs utility interval (MAE threshold)

SQL only. No pandas twin: an aggregate or utility analytic. See the SQL entry and parity.

UTIL-MONTHLY

BAS monthly kWh vs utility monthly bills (% deviation)

SQL only. No pandas twin: an aggregate or utility analytic. See the SQL entry and parity.

Sensor validation and control loops

Range, flatline, spike, stale and rate checks on every modeled sensor; PID hunting.

PID-HUNT-1

Flags control outputs that oscillate enough to suggest loop hunting.

Suspected control-output hunting · Family control · Equipment ahu, vav, chiller, boiler, heatpump · Confirm 0 min · function _pid_hunt_1 · SQL entry

Equation: Rolling 1h total variation of any 0–100% control output (dampers, valves, fan speeds, heat/cool cmds) with span ≥20%, TV ≥500 %·pts, ≥2.5 equivalent cycles, ≥4 reversals — suspected loop hunting (not proof of bad PID alone).

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`loop_enabled`	`loop-enabled`	Status	0/1	bool	0 or 1	optional

Parameters

Parameter	Label	Default	Min	Max	SI unit
`change_deadband_pct`	Ignore changes below	1	0	10	% out
`confirm_min`	Fault confirm delay	0	0	60	min
`minimum_coverage_pct`	Minimum data coverage	80	25	100	%
`minimum_equivalent_cycles`	Min equivalent cycles	2.5	0.5	20	cyc/h
`minimum_reversals`	Min direction reversals	4	1	40	count
`minimum_span_pct`	Minimum observed span	20	5	100	% out
`total_variation_fault_pct`	Total travel threshold	500	50	2000	%/h

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match

SV-FLATLINE

Flags a sensor that stays stuck within a tiny band for too long.

Sensor flatline (stuck) · Family sensor · Equipment ahu, vav, chiller, boiler, weather, zone_other, heatpump · Confirm 5 min · function _sweep_flatline · SQL entry

Equation: Sensor value unchanged (Δ ≤ tolerance) across the flatline window — stuck / frozen sensor.

Inputs

| Role (SQL column) | Haystack role | Quantity | SI unit | Also accepted (converted at ingest) | Expected range | Needed | |—|—|—|—|—|—:|—|

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`flatline_hours`	Flatline window	1	0.25	8	h
`flatline_tol`	Flatline tolerance	0.055556	0.011111	0.555556	°C
`max_silence_hours`	Max sensor silence	0.5	0.25	12	h
`require_operational_gate`	Require operational gate	1	0	1	0/1

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`series_id`	-	assessed sensor series
`sensor_role`	-	Haystack role of the sensor
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)

Parity match

SV-RANGE

Flags any modeled sensor reading outside its physical hard range.

Sensor out of hard range · Family sensor · Equipment ahu, vav, chiller, boiler, weather, zone_other, heatpump · Confirm 5 min · function _sweep_range · SQL entry

Equation: Any modeled sensor reads outside its physical hard range (e.g. OAT −51–54 °C, SAT −1–66 °C, CHWS −1–27 °C).

Inputs

| Role (SQL column) | Haystack role | Quantity | SI unit | Also accepted (converted at ingest) | Expected range | Needed | |—|—|—|—|—|—:|—|

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`max_silence_hours`	Max sensor silence	0.5	0.25	12	h
`range_scale_humidity`	Humidity range scale	1	0.5	2	× (scale)
`range_scale_pressure`	Pressure range scale	1	0.5	2	× (scale)
`range_scale_temperature`	Temp range scale	1	0.5	2	× (scale)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`series_id`	-	assessed sensor series
`sensor_role`	-	Haystack role of the sensor
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)

Parity match

SV-RATE

Flags implausible sustained sensor rates of change using location- and state-aware thresholds.

Context-aware sensor rate of change · Family sensor · Equipment ahu, vav, chiller, boiler, weather, zone_other, heatpump · Confirm 10 min · function _sv_rate_compute · SQL entry

Equation: Implausible sustained rate-of-change for mapped sensors. Thresholds depend on quantity, location, and operating state (steady vs startup/shutdown transient). Engineering screening defaults — tune per site. Alias: SV-SLEW. Distinct from SV-SPIKE (one-sample jump), SV-RANGE, SV-FLATLINE, and PID-HUNT-1.

Inputs

| Role (SQL column) | Haystack role | Quantity | SI unit | Also accepted (converted at ingest) | Expected range | Needed | |—|—|—|—|—|—:|—|

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	10	0	60	min
`design_flow`	Design flow (flow profiles)	0	0	47194.7	L/s
`max_gap_hours`	Max sample gap	2	0.25	6	h
`persistence_min`	Fault persistence	10	5	60	min
`sensor_span`	Sensor span (flow/pressure)	0	0	100000	eng
`transition_window_min`	Transition window	20	5	60	min

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`series_id`	-	assessed sensor series
`sensor_role`	-	Haystack role of the sensor
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)

Parity known divergence: documented in sql/fdd/KNOWN_DIFFERENCES.md: pandas uses profile/median/persistence logic, SQL two consecutive exceedances

SV-SPIKE

Flags an implausible sample-to-sample jump for the sensor type.

Sensor rate-of-change spike · Family sensor · Equipment ahu, vav, chiller, boiler, weather, zone_other, heatpump · Confirm 5 min · function _sweep_spike · SQL entry

Equation: Sample-to-sample jump exceeds the physical spike limit for the sensor type.

Inputs

| Role (SQL column) | Haystack role | Quantity | SI unit | Also accepted (converted at ingest) | Expected range | Needed | |—|—|—|—|—|—:|—|

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`max_silence_hours`	Max sensor silence	0.5	0.25	12	h
`minimum_active_coverage_pct`	Minimum active coverage	5	0	100	%
`require_operational_gate`	Require operational gate	1	0	1	0/1
`spike_scale`	Spike limit scale (global)	1	0.25	3	× (scale)
`spike_scale_humidity`	Humidity spike scale	1	0.25	3	× (scale)
`spike_scale_pressure`	Pressure spike scale	1	0.25	3	× (scale)
`spike_scale_temperature`	Temp spike scale	1	0.25	3	× (scale)

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`series_id`	-	assessed sensor series
`sensor_role`	-	Haystack role of the sensor
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)

Parity match

SV-STALE

Flags when all modeled sensors stop updating — likely a dead data feed.

Stale data (no fresh samples) · Family sensor · Equipment ahu, vav, chiller, boiler, weather, zone_other, heatpump · Confirm 5 min · function _sweep_stale · SQL entry

Equation: All modeled sensors unchanged over the stale window — data feed likely dropped.

Inputs

| Role (SQL column) | Haystack role | Quantity | SI unit | Also accepted (converted at ingest) | Expected range | Needed | |—|—|—|—|—|—:|—|

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`max_silence_hours`	Max sensor silence	0.5	0.25	12	h
`stale_hours`	Stale window	2	0.25	12	h
`stale_tol`	Stale tolerance	0.027778	0	0.555556	Δ°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`series_id`	-	assessed sensor series
`sensor_role`	-	Haystack role of the sensor
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)

Parity match

Imperial display: Δ°C parameters are differences, shown as Δ°F with no +32.

Weather

Web weather versus the site’s own outside air sensor.

OAT-METEO

Flags large disagreement between BAS outdoor-air temp and web weather OAT.

BAS outdoor-air sensor vs Open-Meteo · Family ahu · Equipment ahu · Confirm 15 min · function oat_vs_meteo · SQL entry

Equation: BAS OAT sensor differs from Open-Meteo dry bulb by more than 2.8 Δ°C.

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required
`web_oa_t`	`web-outside-air-temp`	Temperature	°C	°F, K	-	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	15	0	60	min
`oat_err`	Max OAT disagreement	2.77778	1.11111	11.1111	°C
`web_asof_margin_seconds`	Web as-of margin	300	0	1800	s
`web_cadence_seconds`	Web weather cadence	1200	300	7200	s

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity known divergence: weather source: SQL prefers equipment web_oa_* then as-of weather rows; pandas resolves its own web columns

WX-1

OAT sample-to-sample jump > 8.9 Δ°C.

OA temperature spike · Family weather · Equipment weather · Confirm 5 min · function wx1 · SQL entry

Inputs

Role (SQL column)	Haystack role	Quantity	SI unit	Also accepted (converted at ingest)	Expected range	Needed
`oa_t`	`outside-air-temp`	Temperature	°C	°F, K	-51.11 to 54.44	required

Parameters

Parameter	Label	Default	Min	Max	SI unit
`confirm_min`	Fault confirm delay	5	0	60	min
`spike_limit`	Spike limit	8.88889	2.22222	22.2222	°C

Outputs (the same as the SQL twin)

Output	Unit	Meaning
`equipment_id`	-	equipment the row describes
`fault_hours`	h	confirmed fault time
`covered_hours`	h	time the rule could assess (known inputs, gate open)
`fault_pct`	%	fault_hours as a share of covered_hours

Parity match; differs only on edge data: Gap handling: SQL flags

oa_t - previous sample

above the fixed limit whatever the time between samples, pandas scales the limit by the sample gap (limit x dt/poll), so a real change across a >2 h gap is a spike in SQL only.

General

Rules that apply to any equipment: runtime, comfort and elapsed-time analytics.

AVG-ZONE-TEMP

Average zone temperature per equipment

SQL only. No pandas twin: an aggregate or utility analytic. See the SQL entry and parity.

FAN-RUNTIME-HOURS

Fan running hours where fan_cmd > 5% (normalized 0-1)

SQL only. No pandas twin: an aggregate or utility analytic. See the SQL entry and parity.

FAULT-ELAPSED-HOURS

Comfort fault sample count → hours

SQL only. No pandas twin: an aggregate or utility analytic. See the SQL entry and parity.

ZONE-COMFORT-PCT

Percent of samples in comfort band

SQL only. No pandas twin: an aggregate or utility analytic. See the SQL entry and parity.