Sunday, August 23, 2015

Make my own Solar pool heater

My family and I live on Long Island in New York.  Although summer temperatures in the region can get fairly warm, our backyard gets almost full shade from a neighbor's trees.  As a result, our swimming pool doesn't get very much sun and tends to stay cool even on the hottest of days.

2007 was the first year we had the pool.  At the end of the season, I decided to research a solar solution to raise the temperature so that we could have a warmer pool for the 2008 swim season.  Although there are several solar products on the market that can be purchased, they tend to have solar collectors that are a minimum of 8 ft. wide.  Since my back yard is fairly small and the only place that gets full sun is a section of the side yard near my kids swingset, I really needed something smaller.  Naturally, another solution would have been to mount a store bought solar panel on the roof, but I really did not want to mount anything up on the roof of the house.

The following is a link to the site where I got the basic design for my panel:
I found this site to be one of the best on the subject because it explained how to build a very simple and practical solar panel and how to tie it into the pool's plumbing.

In 2008, I experimented with heating the pool using a solar collector that I built.  During the Spring of 2009, I made improvements to this solar collector and built a second.

The two solar collectors can increase the pool temperature by anywhere from 1 to 4 degrees in a day depending on strength of the sun and level of humidity.  The cooler and dryer the weather, the more the heat will escape the pool thru evaporation.  I have found that the most important factor in cumulatively increasing the pool temperature is weather conditions during the night.  If night temperatures drop down into the sixties and the air is dry, all the heat gained during the day will be lost.  Obviously the best conditions for maintaining heat in the water and raising pool temperature is to have warm humid conditions at night which will minimize evaporation and thus keep heat loss in the pool to a minimum.  I have found that the best way to slow heat loss is to use a solar cover on the pool at night.  Solar covers help prevent pool water from evaporating and help maintain heat.  In general, during warm summer conditions, I have raised the pool temperature anywhere from 5 to 8 degrees Fahrenheit, which definitely improves swimming conditions.

Below are pictures of the solar collectors that I built.  Each one consists of a 4x4x3/4" sheet of plywood with a rim constructed of 2x2 pressure treated rail balusters.  I left some spacing in the rim on the lower portion of both sides and the bottom to allow for some ventilation.  The entire front is painted flat black in order to absorb the heat.  The rear is painted white so that it is not visible from the front of the house because it sits with its back to a white PVC fence.  The coil is made up of 200 ft. of black 3/8" PVC flex type sprinkler pipe (Product name is "Funny Pipe" by TORO).  The flexible style pipe was a little bit more expensive than standard 1/2" PVC pipe, but it was much easier to wind into a coil.  It is held down to the plywood with 1/2 " electrical straps that I also painted black.  The front is covered with a 1/4" clear acrylic sheet, held down with stainless steel screws. Along the edges I applied a bead of clear silicon caulk to create a good seal.  The acrylic cover protects the panel from heat loss due to cool air contacting the coils and allows a good amount of heat to build up, providing that we have sunny weather.  The following is a link to the US Plastic Corp. 

1 comment:

  1. Congratulations of building a solar pool, I think it's great that you are able to heat your pool in that way. I was very interested in reading about how it all works and this is definitely something I would consider if I was to have my own pool. Your diagram also made it very easy to understand.

    Benton @ Pool Solar & Spa