Before purchasing a solar pool heating system, you can estimate and compare the costs of using different solar collector models. This will help you determine the potential cost savings of investing in a more efficient type of collector, which may require fewer panels for the collector area needed to heat your pool.

To estimate and compare costs, you need to know the following:

• A collector's thermal performance rating (Btu/day)
• Total number of collector panels or piping for the area needed to heat your pool
• Total installed cost of system.

You can then calculate a collector's energy output per dollar spent or invested using this formula:

(Btu/day X # of collector panels/piping modules) ÷ total installed cost of system = Btu/$ per dollar spent

Example:

(27,900 X 4) Btu ÷ $3,000 = 37.20 Btu/day per dollar spent

If you just know the prices and thermal performance ratings (Btu/day) of collectors, you can use the following formula to calculate the energy output for each dollar spent or invested for different collectors:

Btu/day ÷ collector price = Btu/day per dollar spent

Example:

21,000 Btu ÷ $387 = 54.26 Btu/day per dollar spent

Don't choose a solar pool heating system or collector based solely on its estimated costs. When selecting a solar pool heater, it's also important to consider all of the factors involved in the system's sizing and quality of the design and installation.