Discount Above Ground Pool Heaters

The tables presented for pool heater sizing allow you to gain a quick idea regarding the size of the gas pool heater that you will need for your above ground swimming pool. Table 1 presents the heating requirements for raising the water temperature at a rate of 1 degree F per hour, while Table 2 provides for a rise of 2 degrees F per hour. As is evident, this simply requires a pool heater that has twice the capacity.

These data are simply calculated values, so you will need to make considerations with your eventual pool heater selection, since they are commonly sized in 50,000 BTU/Hr increments. Also, this data is based on the heating units operating at an 80% efficiency. Gas pool heaters are available that exceed this rating, so an appropriately smaller sized unit could be substituted.

Gas pool heaters are rated based on the BTU input of the heater. Natural gas has a heating value of 1,000 BTU/cubic foot, so a 100,000 BTU/Hr heater that operates at 80% efficiency would transfer 80,000 BTU/Hr of heat to the pool water. A heater with an efficiency of 90% would transfer 90,000 BTU/Hr to the water and result in a fuel savings of approximately 13%. This will have a greater impact on your fuel budget the more that you use the heater, so the greater expenditure for a higher efficiency system may justify the higher capital cost.

A pool heater that can raise the water temperature by 30 degrees is needed if you plan to use your pool in early April through October (and you live in the NE US) when the air temperature is 50 deg, but if you only want to extend your swimming season by a month on each end then a smaller sized unit would suffice. A smaller unit would also work out well for you if you can run it for several hours to warm the water or only need to supply the water temperature of the daytime with some additional heat at night or on overcast days.

Again, these tables are presented as a guide. Discuss your specific requirements with your pool equipment supplier. However, for most homeowners with above ground swimming pools, a heater that is rated at 100,000-200,000 BTU/Hr will handle many situations. But if you are to err on one side or the other, you will never be disappointed by choosing a larger unit over a smaller one.

Table 1: 1 deg F Rise/Hr

Table 2: 2 deg F Rise/Hr

One Response to “Gas Pool Heater Sizing Chart”