How Does an Electric Resistance Spa Heater Work?

If you are considering the purchase of a swimming pool or spa heating system, you should research all available options. Different heating systems are appropriate for different swimming pools and spas, and you want to select the heating system that will most benefit you. In this article, we explain how an electric resistance heater works.

An electric resistance spa heater creates heat by applying an electrical current to a heating element, which is a metal resistor. The resistor extends throughout assembly housing inside the unit. The resistor heats when a current is applied to it. The spa water enters the assembly housing, washes over the resistor, heats, and exits the assembly housing warm.

Advantages of an Electric Resistance Heater

An electric resistance heater offers many of the same conveniences as a gas heater. It operates independently of air temperature, so you can easily heat your spa during winter months. And, an electric resistance heater is the most compact heater. As many occupy less than 12 ft³, they are ideal for areas with space restrictions like spas.

Other advantages of electric resistance heaters include: low purchase and installation costs, quiet operation, and small environmental footprint.

Disadvantages of an Electric Resistance Heater

The efficiency of a swimming pool or spa heater is measured by its Coefficient of Performance (COP). The COP of an electric resistance heater is 1.00, which makes it six times less efficient than a heat pump. Due to its low efficiency, an electric resistance heater requires large amounts of electricity to heat a body of water. In fact, electric resistance heaters require so much energy that they are not generally used to heat swimming pools. They are primarily used to heat spas and small therapy pools.

Other disadvantages of electric resistance heaters include: required installation of heavy-duty electrical wiring and high operating costs.

So now you know how an electric resistance heater works. Hopefully this article helps you in your search for a swimming pool or spa heating system. Do you have any thoughts or questions regarding electric resistance heating? Leave a comment below! We at AquaCal would love to hear from you.