Solar Pool Collectors: Performance Rating

As part of our desire to give you everything you ever need to know about solar energy, The Solar Guide presents an independent overview of solar pool collectors, as rated by an independent body with no commercial interest. This information actually comes from a Canadian government study.

If you think about it, Canadians would have to be a good source for this kind of information. Canadians would be more interested than anyone in extending their swimming season and getting maximum energy from their solar pool heaters.

The study also assesses the savings garnered by using solar instead of other forms of water heating. Special thanks to the Canadian Renewable Energy Network.

Collector Ratings

Five manufacturers that sell unglazed solar collectors for heating outdoor swimming pools in Canada agreed to participate in a program to test and publish ratings of collector thermal performance. Ratings for one collector from each participant are included in this directory.

Solar collectors for testing were randomly selected from stock held by each of the participating manufacturers. These collectors were subjected to a series of standardized exposure tests. Then the thermal performance of each collector was measured at the National Solar Test Facility (NSTF) in Mississauga, Ontario, in general accordance with CSA Standard F378-87 (R1998), "Solar Collectors." A detailed computer model, Enerpool Pro , used the resulting thermal performance characteristics of each collector to simulate the operation of a representative Canadian solar pool-heating system under typical operating conditions for the poolheating season. In the table below, the simulated energy production per unit area for each collector has been recorded as the annual delivered energy rating.

Energy Rating of Swimming Pool Collectors

Collector Rated Annual Energy (GJ/m)
Manufacturer Model Area* (m) Vancouver Toronto Montral
Solar Only Solar & Aux.** Solar Only Solar & Aux.** Solar Only Solar & Aux.**
AQUATHERM Solar Industries 4 X 10 3.607 1.3 1.0 1.3 1.1 1.2 1.0
FAFCO Sunsaver 4 X 10 3.631 1.3 1.1 1.3 1.1 1.2 1.1
HELIOCOL Heliocol - 40 3.768 1.0 0.7 1.1 0.8 1.0 0.8
HOT SUN INDUSTRIES Powermat 4 X 10 3.630 1.2 1.0 1.2 1.0 1.1 1.0
TECHNO-SOLIS Techno-Solis 4 X 10 3.672 1.3 1.1 1.3 1.1 1.2 1.1
* From NSTF test report.
** Solar & Aux. represents a solar system that is operating in conjunction with an auxiliary heater, with a fixed set-point of 27.5 C.

The simulated system had a total collector area of 24.5 m, which was half of the swimming pool surface area. For total solar collector areas that represent a larger fraction of the pool area, actual energy delivered would be somewhat lower than tabulated. For example, at 80 percent of the pool area, collector output is approximately 90 percent of that tabulated.

Savings

If you are using a non-solar pool heater, you can estimate the energy-cost savings that you could achieve with a solar pool-heating system with the following equation:

Annual Dollars Saved = [Rated Annual Energy (GJ/m) x Collector Area (m) x Number of Collectors x Cost of Energy ($/GJ)] / Efficiency of Existing Pool Heater

To determine your Cost of Energy, use the following table:

Fuel Unit Cost on Your Bill To get $/GJ, multiply by
Natural Gas _____________ cents/m 0.2686
Oil _____________ cents/litre 0.2585
Propane _____________ cents/litre 0.3917
Electricity _____________ cents/kWh 2.778

The efficiency of pool heaters that use natural gas, propane or oil can usually be assumed to be roughly 0.75; the efficiency of an electricresistance heater can be assumed to be approximately 1.0.

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