1How many cubic feet do you want to heat?
What is the temperature difference needed between the outside temperature and the desired inside temperature?
Establish the DIFFERENCE factor
Establish the BTU factor using the temperature difference in step 2:
What is the insulation or "R" factor?
Calculate the required BTUS:
This is an approximate calculation of the BTUs required to heat this space. If you need greater precision, consult with an engineer to assess your specific requirements.
Propane consumption guide
Here is a simple way of calculating your fuel needs when using a propane heater:
The basic rule:
At -17°C one 100 lb tank provides 64,000 BTU
At -7°C one 100 lb tank provides 94,000 BTU
Just divide your BTU needs by 64,000 or 94,000.
||A 300,000 BTU heater, temperature where the cylinders are located is -17°C
300,000 BTU/64,000 BTU = 4,69 cylinders
Since the law prohibits connecting more than 4 tanks of propane to a single piece of equipment, using 100 lbs tanks is not recommended to get maximum output.