Basement finishing - ductwork question (standalone heatpump) in Georgia


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Old 09-13-15, 08:44 AM
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Basement finishing - ductwork question (standalone heatpump) in Georgia

I'm getting my daylight basement finished and I am located in Georgia. It has it's own ductwork and heatpump system. Two main questions. It is about 1000 sq ft with a rec room, media room, bedroom, and bathroom. Half the walls are buried/poured concrete and half are framed and exposed/above ground

1) Does the supply need to be placed near the exterior doors/windows? I have a bedroom where there is a window but they chose to locate the supply on the concrete wall side.

2) Does there need to be an approximately equal return sized to the supply? The rec room has a large single 8" vent feeding it but no return. The bedroom has a door dividing it from the rec room and it has a small return. The media room has the main return that's a large 10 or 12" line to square opening. The media room is divided with a closed door to the rec room. I am worried about excessive positive pressure in the rec room. I mentioned this to my general contractor and he kind of brushed it off but I insisted he ask the hvac installer. I am awaiting his reply. The contractor said the door gap provides the reruen path. I want to be prepared to cite some requirement for adequate return to match the supply. Is there anything that I can do to force the issue?

Thanks.
 

Last edited by mtnbkt; 09-13-15 at 09:36 AM.
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Old 09-14-15, 10:57 AM
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Welcome to the forums.

Generally speaking, I answer yes to both your questions.
 
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Old 09-15-15, 03:20 AM
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Thanks for the reply. I also feel the answer is yes. Specific to return air matching supply, is there a documented code or suggested guidance that I can refer to?
 
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Old 09-15-15, 08:04 AM
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Generally speaking a return duct should have 1-1/4 to 1-1/2 times the cross-sectional area of the supply duct. Equal to the supply duct at the absolute minimum.
 
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Old 09-15-15, 05:20 PM
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Furd is that codified somewhere?
 
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Old 09-15-15, 06:15 PM
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Maybe, but I couldn't tell you where. It is a common "rule of thumb" that more often than not is ignored on most residential systems.
 
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Old 09-16-15, 05:28 AM
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Return is bigger so you have less noise. Its easier to push the air than it is to pull.
 
 

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