Attic Furnace Detail
Obtain the furnace manufacturers installation instructions and install the furnace to their specifications.
Attic furnace detail. The following are attic furnace installation requirements based on 2009 irc and 2009 imc the codes refer to it as appliances in attics. A 30x22x30 inch high minimum unobstructed access but not less than the largest equipment size. Located in an attic cmc 304 4 furnaces located in an attic area shall comply with the diagram at the bottom of this page. Attic furnace access passageway and platform attic furnace passageway and.
Refer to the current state and local building codes for the minimum r value of air impermeable insulation required for the roof assemblies in your climate. Most updated central air conditioned homes have a new air conditioner split system meaning the ac is broken up into parts. Well mainly it s a way to save space. Fau located in an attic attic access service space c m c 904 crc r807 ventilation.
Fau unit shall be doubled with a minimum 2x6 joists. B 30x30 inch minimum unobstructed passage to remove equipment but not less than the largest equipment maximum 20 distance from access to unit. Attic furnace 2019 california mechanical code sections 904 10 through 904 10 the following are general requirements for an attic furnace based on the 2019 ca mechanical code. Unvented cathedralized attic detail with air impermeable insulating sheathing installed over the roof deck.
So why put an hvac system up in the attic at all. If the attic and roof framing is a pre fabricated engineered truss system an engineering report wet stamped and signed by a licensed engineer shall be submitted for review and approval prior to issuance of a building permit. Cmc section 304 4 appliances in attics. Central attic furnace detail 410 8 kb concrete block pilaster method m 310 8 kb concrete block pilaster method n 299 5 kb exterior door landing details 424 1 kb pool barrier sample detail 207 1 kb sample site plan 117 3 kb standard plan for detached garage 68 6 kb.
Attic hvac systems save space. Attic furnace walkway platform attic furnace installation must comply with you local mechanical code or imc international mechanical code if such was adopted in your area. This handout is intended to provide only general information for further information contact the building safety division. How to install insulating sheathing over the roof deck with a cathedral ceiling.
An attic in which a fau is installed shall be accessible by an opening and passageway 30 x 30 in size. Cmc chapter 9 attic furnace diagram. Attic access may be reduced to 22 x 30 provided the. Additionally if the attic and roof is conventionally framed ceiling joist under the location of the fau unit shall be doubled with a minimum 2x6 joists.