Here is a worksheet for calculating room combustion air.This is needed for when you want to run a single pipe system on a piece of equipment.

Combustion Air Calculation Worksheet for Single-Pipe System

Use the following steps to calculate the required combustion air for an appliance when operating with a single-pipe system:

1. Obtain the Appliance Input in BTUs.

2. Divide the BTU Input by 1,000.

3. Multiply the Result by 50.

4. The Final Result is the Required Cubic Feet of Combustion Air for the Space.