CALCULATING REQUIRED HEATING TIME
The initial time it takes to get your pool warm depends on several factors. First
you will need to determine how many gallons of water are in your pool. If you
know this, you can compute the pounds of water in the pool and the BTU’s
necessary to heat the pool to the desired temperature. Secondly, you need to know
the approximate BTU output of your heat pump at the ambient air temperature.
Finally, we need to know the temperature at which you plan to keep your pool or
spa heated.
Sounds complicated, but it’s not! You can use the worksheet below to calculate
approximately how long it will take your heater to bring your pool up to
temperature. Keep in mind that the time will vary somewhat due to weather
conditions during the period that the heater is in use.
Surface Area of Pool
(Length X Width X Average Depth)
= Pool Cubic Feet
X Gallons per cubic ft.
7.5
= Pool Gallonage
X Pounds per Gallon
8.3
= Pounds of Water
(BTU’s Required to raise your pool 1º f)
(How many degrees do you want to raise the
X # of Degrees
temperature of the pool?)
= BTU’s to heat pool
/ BTU Output of Heater
= Hours of operation
(Time it takes at 80º water, 80º air, 80%
Relative hum.)
X 60º Temperature factor
1.25
= 60º Air running time (Running time adjusted for cooler weather)
APPENDIX II-1
