Determining Gas Swimming Pool Heater Energy Efficiency
New gas swimming pool heaters have a standard test they go through to determine their energy efficiency based on their Btu (British thermal unit) output.
Heater efficiency is the ratio of usable output to energy input. For example, an 80%-efficient heater uses $80 worth of useful heat for every $100 worth of fuel. Therefore, it wastes 20% of the fuel.
Most gas pool heaters feature their efficiency percentage on their nameplates. A pool heater's manufacturer can also provide its efficiency percentage.
Today, you'll find some gas pool heaters with 89%–95% efficiency. The following table shows how much you can save for every $1,000 in annual pool heating costs by installing a gas pool heater that's 95% efficient.
| Current Htr Eff | Cost w/ 95% | Annual Savings |
|---|---|---|
| 55% | $580 | $420 |
| 60% | $630 | $370 |
| 65% | $685 | $315 |
| 70% | $735 | $265 |
| 75% | $790 | $210 |
| 80% | $840 | $160 |
*For every $1,000 in annual pool heating costs


