How Solar Hot Water Systems Work
View PDF | Print View
by: MasonAdams | Total views: 25 | Word Count: 636
If you're interested in using solar energy to provide energy for your home, the first decision is whether you want PV solar panels to create electricity, or solar collectors for solar hot water systems. This article is going to assume that you have decided on the latter, in which case there are a few more decisions you're going to have to make.
Solar How Water Systems
The first decision you are going to have to make when you have chosen to go for solar hot water systems is what sort of solar collector you are going to want to use. That's the name given to solar panels that are used to heat water. There are two types, the evacuated tubes and the flat panels.
With the flat panel solar collectors, the thermal collector which catches the heat from the sun, runs along the bottom of the box. The box has a transparent glass top so that the sun rays can get through. The sun heats the thermal collector, and this heats either the water running through the pipes or the heat transfer material.
It's very similar with the evacuated tubes, except instead of having the absorber plate running along the bottom it is wrapped around the tubes. The advantage of this is that it will catch the heat from the sun from multiple angles.
On the whole then, the evacuated tubes are more efficient and so more popular. They are a bit more expensive than the flat panels though so if your budget is tight then it might be better to go with one of those.
Choices Of Circulation Systems
The other main difference between solar hot water systems has to do with the way the water is circulated. There are two things to consider here, and each of these considerations has two different possibilities.
There are two main areas in which you have to make a decision, but to make it a bit easier there are only two options in each case. One of these areas is whether you want the circulation to be passive, meaning that no pumps are used in getting the water circulated or active, in which case they are. You also have to decide whether you want the water to be heated directly, or indirectly through a heat transfer system.
First then, on the issue of whether the water should be heated directly or by a heat transfer system. There is actually quite a clear winner in this regard, because the heat transfer system is quite a lot better. It is more efficient, and it causes less problems when something goes wrong. If the system goes stagnant, for example, then if the water is going in to the solar collectors then it takes quite a lot of effort to get it out. That isn't a problem when a heat transfer substance is being used.
It's more difficult to choose between an active and passive system though, although there is quite a clear winner in this case as well. First though, the main advantage that you get with a passive system is that it shouldn't need a lot of maintenance, if it needs any at all, because it doesn't have any moving parts.
The active systems have a couple of things in their favour though, and they're pretty major. The first is that it's more efficient to use pumps, and this is going to result in more hot water and better value for money.
Also, there is something else that goes in the favour of the active system. That is that it makes designing the system easier, there is more freedom to put the hot water tank where you want to for example. With the passive system it all has to be worked out so that gravity will do its job in getting the water moving around meaning that there will be fewer options.
About the Author
If you'd like to find out more regarding solar energy, you are able to do so at solar hot water systems, where Mason Turner writes more on this subject. This site also happens to be the location to go should you be interested in receiving a free quotation for an installation.
Rating: Not yet rated
Login to vote
