Heating cost

[Poolsteve]

thinking about trying to heat pool this weekend. temp should be 70 degrees each day, 55 at night. current pool temp is 55.

Does math below make since/sound right?

Total Gallons = 18500

Wind Speed Average = 3.5 MPH

Desired Temperature Rise = 20 degrees

Heater BTU's = 200000

Heater Efficiency = 80%

Fuel Cost per therm = $.35


Our calculations based on your information shown above are as follows:



Total therms required = 38.53

Time (in hours) to raise 18500 gallons of water 20 degrees = 19.26

Time (in minutes) to raise 18500 gallons of water 20 degrees = 1155.79

Cost to raise 18500 gallons of water 20 degrees in 19.26 hours @ $ .35 per therm = $13.48

 

[JasonLion]

That is all roughly correct. The real world is somewhat viable, so actual may be more or less, but that is a good ballpark number.

 

[mas985]

Do you plan on swimming in 75F water? Also do you have a cover? Otherwise it might take longer. You could lose 0.25 to 0 5 deg per hour in heat loss without a cover.