adding heating and air duct to converted garage

Old 10-07-10, 07:12 AM
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adding heating and air duct to converted garage

What size (airflow) do i need for this 11 x 13 room
Old 10-07-10, 12:58 PM
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You first need to do a heat loss / heat gain calculation on the room.
Old 10-07-10, 02:24 PM
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First you must determine the BTU/hr and a rough rule of thumb to get this is to allow 10 to 20 BTU/hr per sq.ft of floor area.

In your case 11x13 = 143 sq.ft of floor area, say 150 sq.ft times 10 = 1,500 BTU/hr

To find now the air flow in CFM (cubic feet per minute) you need the temperature rise. Lets assume the room is to be maintained at 70 F and your heated air is at 100 F. The temperature rise is then 30 F

Then, CFM = BTU / (1.08 * TR) or 1500 / (1.08 * 30) = 46 CFM, say 50 CFM

You substitute your actual conditions to the above to get a more accurate result

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