You can certainly make a DIY solar water heater for your pool for $200 - give or take. It will be simple (and ugly) but you can do it. They will tell you to put together some pipes in a zigzag pattern and put them in a black box with a glass front. Like hot air, hot water rises, so if you put one end of the piping lower than the other, water will circulate and will be heated. They probably will recommend getting a solar powered pump to speed things along. The box will get hot and it will heat water, but you won't have much control over the process. I would not try to make a DIY cheapo heater for your potable water though. If you need a diagram, you probably don't have the plumbing skills you need to be messing with your house. Even if you did, modern solar water heaters aren't just the simple tube designs. They have sensors and pumps and heat exchangers etc that keep the system operating properly.

Here is what I did - My propane heater manual specified how many minimum feet of clearance was needed between the exhaust vent and the nearest combustible material. I built a wooded "shed" with a 6 inch opening all along the bottom and the top of the "shed" is made of privacy lattice and is twice the distance required from the heater. There are two swing out doors for easy access and the flooring is a concrete pad with a buried six inch drainage pipe for my filter backwash. The result is a quieter equipment area, no harmful UV rays to the equipment and cooler environment for the motors. There is NO increase in temperature inside the shed with the equipment running because of more than adequate ventilation.

The topic of internet suppliers has been discussed quite a bit here lately. Here goes again: As a builder I often receive phone calls from people asking me to install a piece of equipment they have purchased over the internet and I always refuse. Why? you ask? If there is a problem with the equipment who are you going to call, the sales office 2000 miles away or the poor schlub who installed it for time and materials. In this market the factory warranty reps are pool service companies who get paid less than an hours call out for each warranty service call and are so busy with their own customers that they have no interest in doing that work. One service company I deal with who are reps for a major manufacturer told me they only signed up to help service their own clients and would not be picking up any new work. One other point. Years ago I was trying to help out a friend of my fathers whose heater wasn't working. I figured out the problem and went to my distributor to order the parts. When I told them the model number they told me in no uncertain terms, "no one in this market has ever carried that heater, tell your customer to call the cheap distributor in Winnipeg he bought it from and get them to fix the thing" Bottom line, it may seem now that it's costing you a bit more but support your local business and buy it from him. That friend of my fathers bought 2 new heaters in 3 years, not much of a savings.

The ambient outside air is where a heat pump will be drawing the heat for the pool from. They will typically draw, at start up, about 50 amps of current @ 240 volts. If you don't have this service available currently, a service upgrade by an electrician would be called for. This may be as simple as adding a sub panel or a more involved full and larger panel. These units typically, on a day with 80 degree day with 80% humidity will be rated at about 125,000 BTUs/Hour and able to inject about 80% of the heat into the water. Lower air temps will reduce the efficiency. Higher temps will increase it some. Water is heated differently from air in that it is harder to heat and releases it's heat more slowly. In order to keep the heat you spent money injecting into the water, a solar cover is strongly encouraged. These covers keep evaporation down. Heat in a pool is typically lost via this mechanism. The term "solar cover" really is a misnomer. Having a roller for the cover will help it last substantially longer than just pulling it off. Heating the pool water goes by weight and not volume. One BTU will heat one pound of water one degree F. There are 8 pounds of water for each gallon. This is a constant. Using a heat pump is the most efficient method of warming the water when you power costs are taken in consideration. Bear in mind, a gas fired heater can be as much as 400,000 BTUs and that in California, where power can be a lot more expensive, gas may be a less expensive option. In Florida, power pricing makes heat pumps more cost effective. Gas fired heaters use either natural gas or propane, not butane. Roof top solar systems need a Southern exposure with low wind. The pool orientation is moot. Clay tile is not, IMHO, a good surface to mount to. If and when the panels develop a leak, someone has to go up and plug the rib, placing the tiles at further risk. Add to it that wet tiles are significantly more slippery and the risks just aren't worth it. Scott