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Actively heating air

Passive space heating

Generating space heat or cooling

Heating a pool

Before you try to embark on any solar hot water projects, it is recommended that you perform a solar site survey to know just exactly how much solar hot water (or electricity) you can expect to reasonably get, knowing the area of the country you reside in and the solar patterns in your area. This survey is only about an hour long, but can prove invaluable.

Methods of Generating Solar Hot Water

The two most easily found, and as a result most common types of solar hot water producing machines are the flat-plate type of collector and the evacuated tube.

Flat Pate Collectors

Flat plate solar collectors are not as expensive than the evacuated tube type , but you also tend to need more of them to achieve the same result .These collectors are simply plates, as their name suggests, much like a car’s radiator inside.

Evacuated Tube Collectors  

Perhaps one of the easiest ways to generate solar hot water that is becoming more popular today is to use evacuated tubes (or “collectors”). These are relatively new , and are glass tubes, removed of all air (a vacuum is a good heat conductor, and allows heat to flow more freely from the outside to the inside metal plates than if air were inside the tube ).

Having tiny metal pipes running the entire length of the tube that are essentially heat fins, their job is to collect heat. At about 6 feet long, they have connectors on each end to connect to the home’s heat circulation system.

A “transfer fluid” that is usually alcohol is circulated in the tubes that can generate, in some areas, as much as 80% of a home’s heat.  Since they are made of glass, they are semi-fragile when removed from their mounts, but once attached I have seen them withstand very extreme wind and even hail without breaking .

Usually found together in groups of ten, these evacuated tubes are positioned in a mount that, as shown in the picture here, can be affixed a few inches above a roof, or can be mounted directly touching it.

The heat created by your tubes can be used primarily in one of two ways to achieve the payoff mentioned earlier:

1. Feeding the hot water produced back into a water heater. This significantly reduces the load on the heater, providing maximum efficiency and minimal load when the water heater is called on. This way, instead of heating incoming water from ground water temperature (usually around 48 to 55 degrees Fahrenheit), it might only have to take the incoming water from 100 degrees to 120, or perhaps not even heat it at all.
2. The heated water/glycol mix can then be circulated into tubes incorporated in a radiant in-floor heating system. This heats the floor of a house using simple tubing placed just below the flooring material itself. The difference this can provide on a cold winter day is often times quite honestly amazing.

Coincidentally, this may be a good time to mention that a water heater blanket (available at most building supply contractor houses) can save a great deal of heat when wrapped around your heater.  Head on over to newenergytips.com for more info on this.