The gas-powered heaters are, by far, the most popular way to heat a pool. There are 2 types of gas-powered pool heaters:
- natural gas heaters (for those of you with access to natural gas)
- propane heaters (for those of you without access to natural gas)
As the name implies, gas-powered heaters use gas, natural gas or propane (which is a gas), to heat your pool. When you hear or read the phrase gas-powered heater when pool heating is being discussed, the type of gas that is being referenced is either natural gas or propane (which is a gas).
The most popular type of gas-powered heater are natural gas heaters. Their popularity is mainly because most households have direct access to a natural gas supply from a local gas company. As the name states, these heaters are engineered to use natural gas as a burn source to generate heat and then transfer that heat to the water circulating through the heater and ultimately back to the pool as heated water.
If you do hot have access to natural gas, the propane heater is a suitable alternative. A propane heater requires that a separate propane tank is located somewhere on the property; this propane tank will have to be re-filled periodically. As the name states, these heaters are engineered to use propane (which is a gas) as a burn source to generate heat and then transfer that heat to the water circulating through the heater and ultimately back to the pool as heated water.
If you are in the market for a gas-powered heater and if you have access to a natural gas supply, then a natural gas heater should be your preferred option.
It is noted that if you have a propane heater and natural gas becomes available in your area, then you can have a conversion kit installed from propane to natural gas so you can use the same heater and just change the gas supply from propane to natural gas. Likewise, if you have a natural gas heater and you determine that it would be less expensive per month to use propane (which will likely never be the case, but if so), then you can have a conversion kit installed from natural gas to propane and likewise use the same heater and just change the gas supply from natural gas to propane. Regardless, the service call (to include the labor, the conversion kit and all required parts) will be less expensive than altogether replacing the heater. This, of course, is contingent that the heater cabinet is sturdy and that the other internal parts of the heater are properly working and functioning.
Regardless if your gas-powered heater uses natural gas or propane as its fuel source, the number of BTUs of any natural gas pool heater is the main criteria that is used to properly-size a gas-powered pool heater. The acronym BTU stands for British Thermal Unit when gas-powered pool heaters are being referenced. It is not important for you to know and understand all of the science and math behind the acronym BTU; just know that the listed BTUs of the heater is the main criteria for properly sizing a gas-powered pool heater. Generally speaking, a BTU calculates the amount of heat that is required to raise 1-pound of water by 1° Fahrenheit. Since a gallon of water weights approximately 8.33 pounds, it takes approximately 8.33 BTU’s to raise the heat of 1-gallon of water by 1° Fahrenheit. If you attempt to multiply 8.33 by the total number of gallons in your pool, your pool heater will be way too small to effectively and efficiently heat your pool. There are certain variables that must be considered. Fortunately, these variables are all noted within a formula to properly size a gas-powered pool heater.
The gas line must also be properly-sized to deliver the required amount of gas (natural gas or propane) to the heater.
You can read the Pool Manual for additional information about pool heaters as well as the formula to properly size a gas-powered pool heater.