Make up air for a 400cfm hood in a less than 1CFM/50 home
estebang
| Posted in General Questions on
I am trying to figure out if I am overdoing this issue. I will be installing a remote Fantech fan to a Fantech hood liner. I am expecting to run this at 400cfm or less. The house tests out at less than 1ACH/50. I know code says I do not need makeup air for this setup but I “feel” it may be necessary because of the tightness of the house. Am I wrong to believe that code says you don’t, but if that requirement is based on the code also saying a house only has to meet 3ACH/50, then my extra tight house should need MAU. The Fantech MAUS’s are a bit overkill for this but are an easy install system.
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Replies
" I am expecting to run this at 400cfm or less."
So that's not the standard, the standard is whether the fan is rated for 400 CFM or more.
Do you have combustion appliances in the house? Make up air is only required if you are burning fuel.
My personal feeling is there is no need for make up air in a house without combustion appliances.
Thanks for the ask to clarify points.
Fantech fan can get to 600cfm but will be controlled to less than 400cfm.
No combustion appliances and dryers are heat pump type. No air infiltration other than through ERV's and an AHU blowing through chilled water.
With no combustion appliances there is no code requirement for makeup air.