Solar Hot Water Heaters During Winter Conditions

Depending on where you live, you may have to adjust your solar hot water heater to accommodate winter weather conditions. Many regions seldom experience freezing temperatures while others deal with them much of the year. Chances are, if you live in climate where the temperatures drop below freezing frequently, the solar hot water heater you purchased and installed is already geared to handle the changing conditions. Closed-loop indirect systems that use a heat transfer liquid or drain back systems are two types of solar hot water heater used in extreme cold regions. Many of the regions that experience the coldest temperatures don’t lack sunlight during the winter, so ensuring that your solar hot water heaters functions year round is mainly an issue of freeze prevention.

Solar Hot Water Heaters During Winter

Even though the winter comes, hot water is still needed–arguably more so. Climates where temperatures routinely drop below freezing require a specific type of solar hot water heater that is not necessary in warmer climates. First, the pipes, or as little as possible of them, should not be exposed. This is not as necessary if you operate a closed loop system with antifreeze. However, some closed loop systems circulate water as the heat transfer liquid which could freeze even during the day.

Closed Loop Systems

Closed loop systems pump a heat transfer liquid such as antifreeze into the solar collector. This liquid is heated by the sun and then pumped back to the storage tank where a heat exchanger transfers the heat energy to potable water. Antifreeze will not fail during cold weather conditions, but you before the onset of winter you should check the amount of it. Any failure of the system during the winter could deprive your home of hot water.

Drain Back Systems

Drain back systems are also closed loop, but they use water as the heat transfer liquid. Water is pumped into the solar collector, heated and allowed to drain back into the storage tank. Because the water automatically drains out of the collector when there is no sunlight and no further water is pumped into it, drain back systems have a built-in freeze protection. If temperatures are below freezing even when the sun is out, drain back systems could still be at risk of freezing.

Recommended Cold Weather Setups

For the coldest temperature regions, closed loop systems with some form of oil or refrigerant as the heat transfer liquid is the best because of its resistance against freezing. Any water in a solar collector could pose a real problem. As a cautionary measure, your home should be equipped with a backup water heater that runs on conventional power just in case your solar hot water heater fails. With this in place, a closed valve could switch systems and keep the hot water flowing to your home even though it’s 10 degrees and snowing heavily outside.

Winter conditions must be accounted for when you operate a solar hot water heater, especially when you live in a climate that experiences extreme low temperatures. Only certain types of solar hot water heaters are ever installed in cold regions, so much of the preparation is a given. Having a backup water heater installed just in case your solar hot water heater fails is a good idea so your home is never left without hot water.