Direct circulation systems can be utilized using water provided from the cold water storage tank or attached straight to city water mains. Pressure-reducing valves as well as pressure relief valves are required, nevertheless, whenever the city water pressure is more than the functional pressure of the collectors. Direct water heating systems must not be employed in places that the water is very hard or acidic, for the reason that scale (calcium) deposits might clog up or rust the collectors.
Direct circulation systems can be employed in places that freezing is occasional. Just for intense weather conditions, freeze protection is normally supplied by recirculating warming water coming from the storage tank. This will lose a few heat however helps to protect the system. A particular thermostat which functions the pump the moment temperature falls below a particular point is utilized in such cases. This sort of recirculation freeze protection must be utilized only for areas in which freezing takes place infrequently (a couple of times each year), considering that stored heat is dumped during this process. A drawback to this system happens in times when there’s power interruption, in which particular case the pump will likely not work and also the system can freeze. When this happens, a dump valve could be set up in the bottom of the collectors in order to supply extra protection.
Benefits of Direct Circulation Systems
Of all the sorts of circulation systems for solar water heaters, direct systems or also called active systems are much easier to understand. The system is basically a closed loop which water circulates through. Coming from a tank, the water moves up by means of solar collectors and down again to that tank just as before – and this is actually the water which you’ll utilize for bathing or for heating up your house. Direct systems are very effective in areas in which water isn’t likely to freeze, simply because plain water is pumped outside the house and way back in again throughout the process. Below are the benefits.
Efficient and Simple
A direct heating system is really quite simple – a single loop which flows the water from your house to be warmed up and back in it once again. This does not only minimize the points of failure on your system, but also making it simpler to maintain and keep working effectively, while also improving the efficiency of the system – in contrast to an indirect system that depends on the heat exchanger to transport heat to the functional water, and that heat exchanger results in a loss of heat which you can’t restore.
It’s less expensive to install a direct circulation system simply because there are much less moving parts and fewer plumbing which has to be set up. This means you will invest less on equipment as well as labor getting it installed and all set to go.
Downsides of Direct Circulation Systems
In extremely cold areas you just can’t utilize a direct circulation system simply because you’d probably come across a lot of issues. The plain water will freeze up and pipes would probably burst outdoors whenever temperatures fall far enough. That is the reason why you won’t see direct systems around cold climates just like Canada or on the northern area of the United States.
More Complex for Several Heating Needs
Whenever you’ve got a direct circulation system set up, it’s very difficult to utilize the same system for numerous heating applications. For instance, in case you planned to heat both your pool as well as your home’s hot water tank, your only option is to install 2 different sets of solar collectors, instead of attempting to route these two water sources via a similar collectors.