Pool Heater Calculator

The goal is to have a heater that has enough capacity to heat the pool to your desired level in a reasonable amount of time. Maintaining that temperature is a lot easier once the pool is up to temp.

First, the capacity of most pool heaters are rated in BTU's or British Thermal Units. One BTU is the amount of heat required to raise the temperature of one pound of water, one degree F. And since there are 8.33 gallons of water per pound, it takes 8.33 BTU's to raise one gallon of water, one degree F.

Swimming pool heaters come in various makes and models. The four main differences in pool heater models have to do with the type of fuel the heater uses (natural gas or liquid propane), the style of ignition your pool heater will employ, the level of emissions the pool heater produces, and the elevation for which the pool heater is rated.

Natural Gas or Liquid Propane? What Will Your Pool Heater Run On?
When selecting your pool heater you'll need to decide between a natural gas and liquid propane model. The type of fuel you decide to use will be based on the difference in availability and price of fuels in your area. The price of the model you choose should not be affected by the fuel type you decide to use.

The Difference Between Millivolt and Electronic Start Pool Heaters.
A millivolt swimming pool heater utilizes a standing pilot light that must constantly stay lit to initiate the pool heating process. An electronic start pool heater removes the need for this pilot light by electronically initiating the heating process. The drawback to the millivolt model is that you may find yourself having to re-light the pilot light if it goes out. This sounds easy enough but anybody who has ever needed to re-light the pilot on a gas stove knows that this process needs to be performed VERY CAREFULLY so as to avoid injury. You can expect electronic start pool heaters to retail for about $150 more than millivolt models.

Low NOx Vs. Normal Emissions Pool Heaters
A "Low NOx" pool heater is a heater designed to release less emissions than a normal pool heater. Recently, some states ( California and Texas ) have mandated the use of these pool heaters. Due to their design low NOx pool heaters are by and large more efficient than traditional pool heaters. This higher efficiency means a higher heat transfer and faster heating of your swimming pool water. Low NOx pool heaters retail for approximately $250 - $300 above traditional style pool heaters.

Pool Heaters Designed for Altitudes 2,000 Feet Above Sea Level
If you live at an altitude 2,000 feet or more above sea level you will need a special model pool heater designed for that altitude. The difference in the oxygen level in the air necessitates this special model. Just one more thing to think about before purchasing a swimming pool heater!