Cost to Operate Natural Gas Heater

[Glenrjack]

I am attempting to make a rough calculation of what it cost to operate my RayPak 400K BTU pool / spa gas heater approx 3hrs/day to maintain my current temperature of 88 degrees Fahrenheit with an auto-cover.

I would appreciate all comments if my calculation is close or if I missed anything.

400,000 BTU/hr X 1 therm/100,000 BTU X 3 hr/day X $1.1269/therm = $13.50/day

 

[ajw22]

400,000 BTU/hr X 1 therm/100,000 BTU X 3 hr/day X $1.1269/therm = $13.50/day

That looks correct.

Heater uses 4 therms/hour.

3 hour run uses 12 therms.