Why heating decides the swim season

Even in a warm climate, water that is not heated runs cold in the cooler months and through every cool snap, and a pool nobody wants to get into is an expensive ornament. Heating closes the gap between the swimming the calendar promises and the swimming the water actually allows, and it is often the difference between a pool used a few times a season and one used most of the year.

The heating question has two parts: which type of heater, and how to run it efficiently. Get both right and a heated pool is a year-round pleasure at a reasonable cost. Get them wrong and heating becomes a bill that makes an owner ration the comfort they paid to build.

Gas pool heaters

A gas heater burns natural gas or propane to heat pool water directly as it passes through.

The benefits of a gas heater

A gas heater is fast and powerful. Because it generates heat rather than harvesting it, it heats a pool, or especially a spa, quickly and on demand, in any weather, independent of the air temperature. For a spa meant to be enjoyed on a whim, and for heating a pool quickly for a specific occasion, a gas heater is the right tool.

The trade-offs of a gas heater

The defining trade-off is running cost. Every hour of heat has a fuel cost attached, and that cost rises with gas and propane prices. A gas heater used to keep a pool warm all season can be expensive to run. A gas heater also requires a gas supply and proper, code-compliant installation. Internally, the heat exchanger, in cupro-nickel or, more durably, titanium, is the heart of the unit.

Heat pumps

A heat pump does not create heat; it moves it, drawing warmth from the surrounding air and transferring it into the pool water, using electricity only to run the process.

The benefits of a heat pump

Because moving heat takes far less energy than making it, a heat pump is highly efficient and inexpensive to operate, often costing a fraction of what a gas heater costs for the same warmth. Many heat pumps are ENERGY STAR certified, and inverter heat pumps are more efficient still. For steady, season-extending pool heat at a low running cost, a heat pump is the economical choice.

The trade-offs of a heat pump

A heat pump heats gradually, not instantly, so it is not the tool for fast, on-demand spa heat. And because it harvests heat from the air, its effectiveness falls as air temperature drops; it works best in mild and warm conditions. For steady pool warmth in a warm climate, neither limit is a real problem.

Solar heating and chillers

Beyond conventional heaters, two systems address temperature in their own ways.

Solar pool heating

Solar pool heating circulates pool water through roof-mounted collector panels that the sun warms, then returns it to the pool. After installation, the heat is essentially free, which makes solar the most economical heating of all over the long term. It pairs perfectly with a heat pump or gas heater as a backup. The trade-off is that it depends on sun and roof space, and it heats gradually.

Pool chillers

In a hot climate, the problem is sometimes the opposite: a pool that heats up so much under summer sun that it stops being refreshing. A pool chiller removes heat from the water, often by evaporative cooling, holding the pool at a genuinely refreshing temperature. Some heat pumps are heat-and-cool units that do both jobs.

Pool covers and energy efficiency

Heating equipment is only half the story. The other half is not losing the heat, and not wasting energy elsewhere, and this is where a pool's running cost is genuinely controlled.

A pool cover, solar blanket, or liquid solar cover transforms heating economics: a cover holds heat in overnight, so the heater works far less to maintain temperature. Heating an uncovered pool is heating water and then letting much of that heat escape into the night air. Beyond heating, the variable-speed pump is the biggest efficiency lever, since the pump is the pool's largest electricity user. LED lighting, correctly sized plumbing, and smart automation that runs equipment only when needed all reduce the pool's energy use. Many regions offer rebates for variable-speed pumps, heat pumps, and solar heating, which improve the economics further.

A cover is the single most cost-effective heating upgrade there is. Heating without a cover wastes a large share of every dollar of heat into the night air.

Choosing pool heating and running it efficiently

The smart approach is to match the tool to the task. A heat pump, or solar, is the efficient choice for steady, season-long pool warmth. A gas heater is the choice for fast, on-demand heat, especially for a spa. A chiller, or a heat-and-cool unit, answers a pool that overheats in summer. Many of the best pools combine systems: solar or a heat pump for the pool, a gas heater for the spa. Whatever the choice, the equipment must be correctly sized to the pool.

Then run it efficiently: pair any heater with a cover, run a variable-speed pump, use automation to heat only when needed, and take advantage of any available rebates. WETYR Pools sizes, installs, and services pool heaters and chillers, designs solar pool heating, and builds energy efficiency into every pool, so the water is the temperature you want, every season, without a running cost that makes you hesitate.