Cold air return - 2 furnaces


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Old 12-06-23, 12:36 PM
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Cold air return - 2 furnaces

I have 2 furnaces and am confused about my cold air returns. I have one room that is connected to furnace A and the same rooms’s cold air return goes to furnace B. Is this ok - or is this a problem?
 
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Old 12-06-23, 01:49 PM
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So, do your two furnaces share a common cold air return or are there two separate air return systems that do not coincide with where the heating vents (cross connecting)?

 
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Old 12-06-23, 02:26 PM
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they look separate - but the one room I have opened up is definitely going to the other furnace.
 
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Old 12-06-23, 02:58 PM
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To get the best circulation you'd want the return to be on the same furnace as its supply.
 
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Old 12-06-23, 03:35 PM
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understood! but that would require a lot of rework - there was a reason they did it like this lol. Is it a deal breaker like this? (not sure how this work passed an inspection)
 
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Old 12-06-23, 04:44 PM
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The inspectors don't look for things like that. That's up to the installer.
The inspectors look for things like duct fastening, sealing, flue ducting, gas line treatment.

Is it a deal breaker.... probably not.
 
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Old 12-07-23, 07:08 AM
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Since that room is cross connected you need to make sure there is ample air return available. Worst is a tight fitting door that won't let much air leak past. That can be fixed by cutting a few inches off the bottom of the door to allow the air to get back to the correct furnace.
 
 

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