Originally Posted By: apolillo This post was automatically imported from our archived forum.
Fellow Inspectors,
Gas fired furnace and water heater in sealed closet. 120,000 total btu’s. Combustion air supplied by 7" duct from crawl space. My calculation says that 120,000 btu’s would require a duct with about 60 square in. The 7" duct has about 38 square inches. The crawl space is vented and the vents are open. Your thoughts…
Originally Posted By: cradan This post was automatically imported from our archived forum.
You need 30 sq. inches net; you want to make sure that if the crawl is the sole source of combustion air for the furnace and water heater , that it has ventilation capacity of at least 2x (60 sq. inches) the combustion air requirement for your two appliances.
Originally Posted By: apolillo This post was automatically imported from our archived forum.
What about this? The single pipe fails to meet the requirement for two permanent openings - one within 12" of the ceiling, the other within 12" of the floor. The single opening is in the middle between the ceiling and floor.
Originally Posted By: tallen This post was automatically imported from our archived forum.
apolillo wrote:
What about this? The single pipe fails to meet the requirement for two permanent openings - one within 12" of the ceiling, the other within 12" of the floor. The single opening is in the middle between the ceiling and floor.
Anatol
That's a problem.
For crawl air, it must be, lower ( from the bottom) air. Any other point not good.
Also,the crawl should have 18" of clearance from the joist to the ground.
Originally Posted By: jmurphy1 This post was automatically imported from our archived forum.
One of the issues you guys may be overlooking is the sound emitted from the furnace. I see different ways that people have tried to sound proof the closet because the noise level is so high that it wakes them up or if the furnace is in the living room area the sound level can be so high that you can’t hear the TV when the furnace kicks on.
Originally Posted By: apolillo This post was automatically imported from our archived forum.
I contacted my clients. I recommended that the combustion air vent be evaluated by a licensed HVAC tech. Louvered doors are not pratical in this installation due to noise. Thanks All…
