For the purposes of this overview, I’m going to hit on two options you have for installing solar power in your home – collectors and panels. Keep in mind, however, that you can also take advantage of passive heating systems to draw power into your house through special insulation or simple glass windows – both details we’ll cover in the final section.
For a solar heating installation, you’ll need a variety of parts, depending on what your heating system will be used for.
The solar collector will either be a flat panel attached to your main tank or a network of tubes that will run water through to be heated. The actual size of most solar collectors is around 4-8 feet, though some can be as large as 12 feet if you have a particularly large tank.
If you have a lot of cold or rainy weather, you may want to consider evacuated tubes for your collector as they cut down on outside temperature influences – a major factor in the winter. Only the sun’s energy will impact the temperature of the water or coolant in your collector this way.
A solar storage tank acts as the transitional device between the collectors and your water heater. If you use a closed loop system, the water will be heated in the storage tank by a series of coiled pipes that come from your collector. If you use an open loop system, the water will be pumped directly to the solar collectors for heating and then returned to the hot water tank to be used.
This isn’t necessary in an open loop system that is completely disconnected from the grid, but it is highly recommended because you never know when you’ll lose the sun or need some extra hot water. A backup hot water heater will remain in service, only producing hot water when your solar tank runs empty or the thermostat drops too low on the current supply. You can link them up so that hot water from you solar collector goes directly to the hot water heater and then back to your household supply.
You’ll only need a water pump if you opt for an active system that requires the transfer of coolant or water from your solar collector to a separate tank and then to the hot water heater. You’ll likely only worry about your pump once as they last for 10-20 years and can be powered by any power source in your home – solar or grid-based.
If you have a closed loop system, you’ll need a heat exchanger to transfer heat from the solar collector to your cold water supply. This is usually done by running coolant through a series of pipes and back to a solar tank or the hot water heater. Another alternative is to have a pipe wrapped around another pipe, transferring heat to your fresh water as it is transferred to the facet or bathroom.
Controls and Valves
A number of controls and valves are needed for different types of installations. The “controls” will help to determine where the water is pumped and when the hot water is collected using a thermostat in your hot water tank. The isolation valve is used to cut off and isolate your solar tank if there is ever problem, such as a leak, contamination, or improper heating. This way, you can cut off the solar heated water while maintaining a direct line to your hot water tank if needed.
Another valve you may want to use if you have an open loop system that doesn’t use pumps or controls is a tempering valve. This will allow you to directly impact how hot the water coming out of your facet is. If your water gets too hot, adjust the tempering valve to add more cold water to the mix and get it right.
Installing the Heating System
For the simplest heating systems – the ones where you add a few pipes and install a solar collector and tank on your roof, you can likely do it on your own without any help. However, the more advanced closed loop systems require a great deal of alternation to your plumbing and may even require special permits, so it is a good idea to discuss your solar heating plans with a contractor before starting any new project.