HVAC Ductwork, Equipment & Controls

Mech/Elec

Ductwork Fabrication & Installation

ItemValue
Rect. gauge (600×300 LP)24-ga galvanized
Large trunk (1500×900 MP)18-ga w/ cross-break stiffening
Longitudinal seamPittsburgh lock
Transverse jointsTDC or S-drive
Sealing (supply)ULC-S110 mastic; Seal Class A
Sealing (return)Seal Class B minimum
Trapeze hanger spacing2400 mm max (rect. ≤900 mm)
Insulation (uncond. space)50 mm FSK wrap; RSI 1.4 (R-8)
Flex duct max length1.5 m (diffuser neck only)
Sanctuary branch velocity≤ 5 m/s

Equipment Setting

ItemSpec
RTU curb level tolerance± 3 mm across diagonal
AHU housekeeping pad100 mm min. above fin. floor
Vibration isolatorsAll rotating equip.; spring + neoprene
Flex connectors (equip.)≥ 150 mm at supply & return
Condenser placementAway from sanctuary walls & gathering areas

Refrigerant Piping (313A only)

Fire & Smoke Dampers

TypeTriggerTesting Interval
Fire damperFusible link @ 74°CAfter install + every 4 yrs (OFC)
Smoke damperFire alarm signalAnnually (OFC)
Combination F/SBoth methodsAnnual (smoke) + 4-yr (fire)

Controls & Church Zoning

ItemSpec
Sanctuary NC targetNC-25 to NC-30
Min. independent zones4 (sanctuary, fellowship, offices, classrooms)
ERV effectiveness (min.)65% sensible at design heating
CO2 demand ventilationAssembly spaces > 200 occ.
VFD fan energy savings50% speed = ~87.5% energy reduction
Setback (unoccupied)15°C heat / 30°C cool

Sanctuary Airflow

Exhaust Systems

SpaceRate / Requirement
Washrooms25 L/s per WC or 10 ACH
Parking garage7.5 L/s per m² (CO sensor modulated)
Kitchen (Type I hood)ULC grease duct, 16-ga cont. weld, rated shaft
Mech room (gas equip.)Cont. exhaust; interlock w/ gas firing

Code References

Safety — Do Not Forget

Pro Tips