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Return in encapsulated conditioned crawlspace?

George Wise | Posted in General Questions on

Good Morning. 

Were building a new home with a encapsulated, conditioned crawlspace. The main level Air Hander being placed in the crawlspace. The duct plans show a small supply register for the crawlspace but no return. Would that be code/normal? I would have thought that it being encapsulated and conditioned, you would have both.  With only the supply present, return air has to leak in from either leaks between the main floor and the crawlspace and from the AHU filter area. 

Is this correct? 


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  1. C L | | #1

    Great question. I'm also interested in the reply to this...

  2. Steve Knapp CZ 3A Georgia | | #2


    Allison Bailes has a great article that addresses your question ( He advises that including a transfer grill is part of the code but not his preferred method for controlling crawlspace humidity. It is better to avoid air exchanges between the crawlspace and living space and use mechanical dehumidification to control humity levels in the crawlspace.

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