Heating of Swimming Pools
Both pool covering systems floating atop the water and separate solar thermal collectors may be used for pool heating.
Pool covering systems, whether solid sheets or floating disks, act as solar collectors and provide pool heating benefits which, depending on climate, may either supplement the solar thermal collectors discussed below or make them unnecessary. See Swimming Pool Covers for a detailed discussion.
Solar thermal collectors for nonpotable pool water use are often made of plastic. Pool water, mildly corrosive due to chlorine, is circulated through the panels using the existing pool filter or supplemental pump. In mild environments, unglazed plastic collectors are more efficient as a direct system. In cold or windy environments evacuated tubes or flat plates in an indirect configuration do not have pool water pumped through them, they are used in conjunction with a heat exchanger that transfers the heat to pool water. This causes less corrosion. A fairly simple differential temperature controller is used to direct the water to the panels or heat exchanger either by turning a valve or operating the pump. Once the pool water has reached the required temperature, a diverter valve is used to return pool water directly to the pool without heating. Many systems are configured as drainback systems where the water drains into the pool when the water pump is switched off.
The collector panels are usually mounted on a nearby roof, or ground-mounted on a tilted rack. Due to the low temperature difference between the air and the water, the panels are often formed collectors or unglazed flat plate collectors. A simple rule-of-thumb for the required panel area needed is 50% of the pool's surface area. This is for areas where pools are used in the summer season only, not year 'round. Adding solar collectors to a conventional outdoor pool, in a cold climate, can typically extend the pool's comfortable usage by some months or more if an insulating pool cover is also used. An active solar energy system analysis program may be used to optimize the solar pool heating system before it is built.
Read more about this topic: Solar Water Heating
Famous quotes containing the words heating, swimming and/or pools:
“If the factory people outside the colleges live under the discipline of narrow means, the people inside live under almost every other kind of discipline except that of narrow means—from the fruity austerities of learning, through the iron rations of English gentlemanhood, down to the modest disadvantages of occupying cold stone buildings without central heating and having to cross two or three quadrangles to take a bath.”
—Margaret Halsey (b. 1910)
“Loosed betwixt eye and lid, the swimming beams
Of memory, blind school of cuttlefish,
Rise to the air, plunge to the cold streams....”
—Allen Tate (1899–1979)
“The eastern light our spires touch at morning,
The light that slants upon our western doors at evening,
The twilight over stagnant pools at batflight,
Moon light and star light, owl and moth light,
Glow-worm glowlight on a grassblade.
O Light Invisible, we worship Thee!”
—T.S. (Thomas Stearns)