Originally Posted By: anatol polillo
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Had a townhouse today. Utility closet, non-louvered doors. In the ceiling, there is a 5" air inlet from the attic that terminates at the ceiling. 50,000 btu input gas fired furnace and gas fired water heater in closet.
"A ventilation air inlet grille located in the wall or door, level with or below (D) the combustion air inlet to the lowest burner. The area of the grille must provide 1 square inch for every 2,000 Btus per hour of natural gas input to gas equipment in the area."
By my calculations a 50,000btu input furnace will require a minimum of 25 sq in. The vent provided will only provide 19 sq in. This is not enough for the furnace and water heater combined.
Is my assumption of 1 sq in per 2,000 btu correct?
The gas was off, so I was not able to fire the furnace or water heater.