We are in process of building a home in North Texas. As part of the construction, we have encapsulated the attic with open cell spray foam. In essence, the attic is part of the home's conditioned air space.
My HVAC contractor installed, with our blessings, a system whereby the fresh air return entails about three to four feet of duct and then is open into the attic. This is lieu of having fresh air returns using duck work to the air handler. The HVAC contractor feels the air in the attic needs to be conditioned as well as the home (1 story home).
Prior to starting construction, I engaged an independent energy inspector primarily for the spray foam insulation. As part of his services, he also inspects the installation of the HVAC system. When he saw the open fresh air return on the HVAC, he went ballistic – stating that it violated code to use the attic as part of the fresh air return.
My HVAC contractor provided me several names of other builders that use the open fresh air return in the attic with great success and counters that these have passed inspection. He, however, indicated that I wanted enclosed return; he would modify the system without charge. Please note that I have a green tag from the city building inspector.
I wanted to submit this question for discussion. I ask that you not debate the enclosed attic system since it is a given.
I would appreciate if anyone else has used the concept of using the attic as part of the return without corresponding ducting.
Thank you for your comments.