Valuable Resource for Building Inspectors in the City of Alameda
Furnace
FURNACE
A valid permit and plans must be on-site R106.3.1
Ultra-Low NOx required per BAAQMD
Manufacturer’s instructions must be left with the unit CRC R106.2
Design, construction, and workmanship shall comply with accepted engineering practices and shall be of such character as to secure the results sought to be obtained by this code. CMC 309
Combustion Air/Venting (BTU/20 or 50cu ft/1,000 Btu/h) CMC 701
Direct Vent: all air for combustion must be derived from outdoors CMC definitions
Where the vent connector used for an appliance having a draft hood or a Category 1 appliance is located in or passes through an unconditioned area, attic, or crawl space, that portion of the vent connector shall be listed Type B, Type L CMC 802.10.1.1
Combustion air: (upper and lower – commence within 12” top and bottom – horizontal ducting + 2X size) CMC 701.4
PVC vent: must have contrasting colored primer – 2% slope back to unit – length, and # of fittings per MI and CMC 802.4.2
Combustion air from the attic: no screen on the vertical opening CMC 701.11(5)
Louvers: metal minus 25% wood 75% – motorized = interlock – (25 sq in/0.75) CMC 701.10
Venting/Termination: CMC 802.5.4
B-vent:
No screws or tape CMC 802.6
Clearance: 1” to combustibles per listing – Single wall 6” CMC 802.7.3.4
One offset ≤ 60° from vertical. Total horizontal offset = 75% of the total height. CMC 802.6.3.2
Connector: 1:1 ratio vertical to horizontal. No dips or sags. CMC 802.10.7.2
Vent Connector: Max Horizontal Length CMC 803.2.1 18″ in length per inch in diameter Diameter Max Length 3″—————-4.5′ 4″—————-6′ 5″—————-7.5′ 6″—————-9′ 7″—————-10.5′ 8″—————-12′
General
Manufacturer’s instructions left with the unit CPC 507.24
Mini Splits: disconnecting means must be adjacent and in sight of equipment. or circuit breaker lock-out installed CEC 440.14
Clearances: upright 5’ CMC 904.10 and MI – horizontal MI
Garage installation: 18” and protection from damage CMC 305
Bedroom/bath installation: listed, self-closing, gasketed, exterior combustion air – direct vent units are exempt CMC 904.1(1-2)
New furnace in CS/Basement with < 2 x 10 joists = Sheetrock on the underside of the crawl space floor joists for the room footprint above the furnace only per the BO. CRC 302.13.
6” clearance below the hanging unit
This now includes all electrical and gas appliances
Sheetrock must be water-resistant or painted per the BO
Like-for-like replacements are exempt – this means the same type of device in the same location
24” wide walking path in the attic. Length of the passage: < 6’ in height 20’ max length CMC 304.4.1
22 x 30 access (crawl space same)
30 x 30 working space CMC 304.4.3
Ducting insulation CMC 604
Service light and outlet CMC 304.4.4
Ducting support (no sags) CMC 603.8 and MI
Clearance from fire box to rafters in attic CMC 904.2 and MI
Pan if water damage is possible (see condensates) and CMC 310.2
Ducts penetrating garage wall to living space 26ga metal R302.5.2
Building > 15’ = interior ladder CMC 304.3.1
Smoke detector required (factory installed) in supply duct for > 2,000 cfm
Air balance report CMC 407.3.1
Furnace platforms for plenums must now be sealed sheet metal
Wall Furnace CMC 907
No offset in the wall
12’ min rise of the vent above the bottom of the wall furnace
Attic insulation shield
First set of double top plates, spacer only; all others get fire stop plates
Cut double top plates flush with studs
Electrical
All work done in a neat, workmanlike manner CEC 110.12
Dedicated circuit required CEC 422.12
Type S fuse MI
Check nameplate for max over-current fuse (SSU)
Hardwired disconnect within sight and dedicated CEC 422.31
The panel must be labeled CEC 110.22.A
Breakers match panel mfg or certified replacement CEC 110.3.B
Service receptacle within 25’ and in sight CEC 210.63 and CMC 304.4.4
