Heating swimming pools is one of the most effective applications of solar energy today.

Homeowners often spend as much heating their pools during the summer as they do heating their homes in the winter! The cost of a solar pool heater is much less than that of year-round systems because there is no need for panel glazing or freeze protection during the pool season. An absolute minimal operating cost means that the initial investment can be paid off with the savings in as little as 3-5 years while enjoying the benefits of an extended pool season.

The operation of a solar pool heater is simple. Pool water is sent to the collector panels (typically mounted on your roof) usually by the existing filter pump. Depending on your particular setup, installing a solar system may require a larger pump. As the water circulates through the panels it absorbs the heat of the sun and is then discharged back into the pool, raising its temperature. There are a variety of panel sizes and configurations that can be adapted as needed to suit the individual’s requirements. Systems may be also automated to control and maintain a user-defined pool temperature. Our tough, versatile panels are made right here in Canada, and come with a 10 year manufacturer's warranty. Ask for details.

Site evaluation for the panels of a solar pool heating system is similar to the siting of collectors for residential hot water systems, with a few variations. Since the system is being optimised for summer use, where the sun progresses from northeast to northwest with longer days, the panels can be placed on east and west-facing roofs. However, the system may have to be enlarged to compensate for the loss of sunshine hours in the morning and the evening.
Sizing a solar system for a pool is straightforward, based loosely on the surface area of the pool. Important information for sizing also includes roof orientation, pool shading, and whether or not an insulating blanket is being used. Assuming a south facing roof, unshaded pool, and a blanket, use a figure of 50% of the area of the pool. Without a solar blanket, which works to retain much of the pool’s heat (particularly at night), increase panel area to 75% of the pool area. For pool shading, add 5% for each hour that the pool is shaded between 10am and 4pm.
For shaded pools without blankets, or unfavourable roof orientation, the panel area can approach or exceed 100% of the pool surface.

System performance is competitive with conventional heating systems. The solar pool panels usually heat the water to between 3°C (5°F) and 5°C (8°F) warmer than the pool would otherwise be. This usually takes several days, depending on the amount of sunlight, the air temperature, and that of the pool water. As the pool becomes increasingly warm, so the efficiency of the solar system decreases – experienced as lower daily temperature gains. A properly sized solar pool heating system can raise a pool from 50°C to 80°C in 5 consecutive sunny days in May.

Installing controls on the solar pool heating system will produce additional energy because the system activates automatically when the sun's energy is available. If the pool gets too hot the solar system can be switched off or used to cool the water by running it at night.

There is no precipitation of lime or calcium within the solar pool panels as commonly afflicts conventional gas heaters, due to the low temperature differences between panel heated water and the rest of the pool (3 to 5°C as opposed to 50°C for a gas heater). Panels operate at 10 to 12 psi, though may take higher pressures up to 40 psi.

Solar pool heating features attractive economics. A solar pool heating system will pay for itself in short order, typically between 3 and 5 years.

A common 16 x 32 ft pool, opening on 24th May and closing on Labour Day weekend, using a pool blanket and maintaining 27°C (82°F) with natural gas will cost between $400 and $800 per season for the fuel. A solar pool heater has a higher outlay at first, but the cost of sunshine is zero, and not subject to rising prices. Many homeowners who purchase a gas heater use it for the first year and then turn the thermostat down (shortening the pool season) after realizing the high cost of running the system.

©2006 Nexus Solar Corporation / Solcan Ltd.