· by Michael Blair, Nashville's Pool & Spa
Middle Tennessee gives a naturally long pool season, and heating extends it meaningfully at both ends. Which option suits depends on whether you want warmth on demand or warmth cheaply.
Heat pumps
They move heat from the air, which makes them very efficient — until the air gets cold. In Nashville that suits spring and autumn extension well and shoulder-season use in cold snaps less well.
They heat slowly, so they suit maintaining a temperature rather than raising one quickly.
Gas heaters
They heat fast and work regardless of air temperature, which suits occasional use — a weekend, a party — rather than continuous warmth.
Running cost is considerably higher, so keeping a pool warm all season on gas is expensive.
- Heat pump: efficient, slow, best for maintaining temperature
- Gas: fast, weather independent, expensive to run continuously
- Solar: cheapest to run, weather dependent, needs roof area
- A cover reduces heat loss more than any heater adds
Solar
Panels on a roof circulate pool water to collect heat. Running cost is essentially the pump, and it works well in Middle Tennessee sun during the season.
It needs adequate unshaded roof area and it does not deliver on demand, which some households mind and others do not.
The cover matters more
Most heat loss from a pool is evaporation from the surface. A cover reduces it dramatically, and in shoulder season it does more for water temperature than a heater running against an open pool.
Whatever heating you choose, a cover makes it several times more effective.