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Return air size

268 Views 2 Replies 2 Participants Last post by  JWindmill
When calculating return air grille size, do I add up all the return air grilles, or does the calculation only apply to the main return? I have 5 total (2 main floor bedrooms, 2 in finished basement, main return in living area). I’m putting new hardwood down and I’m about to cut the hole for the main return.
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It all counts but you have to take into account the smallest measurement - maybe the grill is bigger than the duct, so you would have to calculate based on the duct cross sectional area. Overall, return area should be 100-150% of vent area.
1 - 1 of 3 Posts
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