Factors to consider when sizing a gas pool heater for a swimming pool or spa. . 200 - 300 BTU heaters, 10,000 gals to 20,000 gals, up to 500 sq ft. 300 - 400 BTU . For pool heat pump sizing, as a general rule, plan on 50,000 BTU of pool heat pump for every 10,000 gallons of pool water. . Solar Pool Heater Sizing Guide. Jul 6, 2017 - Don't let sizing your pool heater can be a trying task. . advice for every pool set up and sooner, rather than later, I'd have to . A lot of pool owners assume that you use your pool's gallon size to determine your heater size. In order for 20,000 gallons of pool water to heat 30 degrees you would use the calculation: 20,000 x 8.3 x 30 = 4,980,000 BTU total. This means that it would take 207,500 BTU's per hour in order to raise this 20,000 gallon pool from 50 degrees up to 80 degrees in a 24 hour period of time. Learn how to size your swimming pool pump heater so that you can get the right size . Whether you're looking for equipment or accessories for your pool, we have everything you need to take care of . Size at 5 BTU's per gallon or 1.3 to 1.5 BTU's per litre of water. . Up To 20,000 Gallons Saltwater Pools Buyers Guide. Or approximately 100K BTU's for every 10,000 gallons of pool water. For inground pools less than 20,000 gallons, small gas heaters like the Raypak 206K BTU output are suitable. Pools up to 30,000 gallons should look at the Pentair 300K BTU or higher, and pools over 50,000 gallons should look at the Hayward 500K BTU. Determine the best heater size for your swimming pool. . the lowest air temperature during the coldest month the pool will be heated. . Enter Cost Per Gallon. . need,what size heat pump pool heater do i need for 20000 gallons swimming btu calculator the rubber guide to,swimming pool heater size calculator pump for . The larger your pool, the more powerful your heater will need to be, so that means you . That means that if you have a swimming pool that holds 20,000 gallons, . Sep 7, 2011 - What size pool heater is a simple question to which there is no simple answer. . Home→Posts→Pool Heaters Information→What Size Pool Heater Do I Need? . capacity of the pool or the surface area but this is very just a general guide. . 200 – 300 BTU heaters, 10,000 gals to 20,000 gals, up to 500 sq ft. Determine what size of gas or electric heat pump pool heater you will require. . There are two heating conditions you will need to be aware of - heating from cold . For the 30,000 (20' x 40' pool) gallon example: 10,412 x 20 = 208,240 BTUs .