Solar water heating, or solar domestic hot water systems, are a cost-effective means of generating hot water for your home.

The fuel they use from the sun is free, renewable energy and, contrary to what you might think, can be used in virtually any climate.

Solar Heat Works In The Arctic!

One thing about the arctic is that it gets a lot of sunshine. Recently monitored solar water heating systems in Canada’s Yukon verified these results:

• On a clear day starting with a low temperature of -41c and reaching a high of -33c, the solar panels were heating the water to +35c (about 95° Fahrenheit)
• Beginning with a low of -33c and warming to -25c, the water was heated up to 72c (about 161° Fahrenheit) – far too hot to put your hand in

Today’s solar water heating panels are simple and reliable, and can provide trouble-free operation for 40 years or more and can generate 50% of their thermal output on cloudy days.

How They Work

A solar water heater system includes solar collectors and storage tanks. The two types of solar water heating systems are active, which have circulating pumps and controls, and passive, which don’t.

Active Solar Water Heating

There are two types of active solar water heating systems:

• Direct circulation systems for climates where it rarely freezes
• Pumps circulate household water through the collectors and into the home
• Indirect circulation systems for climates prone to freezing temperatures
• Pumps circulate a non-freezing, heat-transfer fluid through the collectors and a heat exchanger which heats the water that then flows into the home

Passive Solar Water Heating

A passive home solar system is less expensive than an active one, but also not as efficient. However, passive systems can be more reliable and may last longer. There are two basic types of passive systems:

• Integral collector-storage passive systems for climates where it rarely freezes
• They are well-suited to households with significant daytime and evening hot-water needs
• Thermosyphon systems work on the principle that warm water rises as cooler water sinks. These systems are reliable, but installers must pay careful attention to roof design as a heavy storage tank is part of the system. They are usually more expensive than integral collector-storage passive systems.

Other Considerations

Solar hot water systems almost always require a backup system for cloudy days and times of increased demand with conventional storage water heaters commonly being used for this purpose. The backup system could be part of the solar collector, such as the rooftop tanks used with thermosyphon systems. It may make sense for you to have a tankless water heater as a backup.

Solar Heating System Demo

Manufacturers

Many manufacturers of conventional home hot water systems also make solar heating systems. Rheem is one example of a supplier of all types of hot water systems. If you would like to take advantage of the extreme energy efficiency of solar hot water, a consultation with a professional at dealer-authorized Efficient Furnace in Vancouver, should be your first step.

By: Andrew Lake