Solar heating systems can refer to both heating water and heating air. Whether you are heating water or air in your home, a solar system can help reduce utility bills as well as reduce your carbon footprint.
The principal is generally the same for both in that either liquid or air is heated through a series of tubes that are directed toward the sun. As the liquid or air heats up, it expands and moves up through the tubes, eventually exiting through an output at the top. Cool liquid or air then comes through an intake at the bottom of the panel, completing the cycle.
For people who can’t afford to install a solar energy system, solar heating is a cheaper alternative. It reduces the heaviest part of your energy bill, heating, but at a fraction of the cost; a solar heating system, depending on what you get and how much you do yourself can run anywhere from $100 to $6,000.
You can use a solar heating system to heat your domestic hot water, swimming pool, or the air in your home and outbuildings. However, there are a few things to consider first, to determine whether it’s the right system for you.
Is solar heating right for your home?
First, you will need a sunny place to put the solar collectors; they should be receiving direct sunlight during the main part of the day. You need to consider any bi-laws or other local regulations that dictate where and what can be placed in visible places such as your roof. Should any exist, you can then make it your second task to work on getting these changed so that clean green energy can be harvested easily!
You will need about 54 square feet of space for the collector. This can either be on a roof, or on a frame attached to the roof, or even on a wall.
If you are considering a solar hot water system, you will need to either have the space to add a second hot water tank, which will be the solar cylinder, or the capacity to retrofit the existing tank with a solar heating coil or replace it with a solar hot water tank.
If you live in a cold climate, where there is the potential for water in your rooftop solar collector to freeze, then you need to either use an indirect or closed-loop system that heats a heat transfer liquid (such as propylene glycol) that won’t freeze but transfers heat to the potable water through a heat exchange system. I explain how a closed-loop system works in this article. Alternatively, you can just dismantle the system in winter and use it during the warmer months.
You want to be sure that existing systems will be compatible with a solar heating system. If you’re not terribly confident with your DIY skills, then you’ll likely be having someone install the system anyway and professional installers will be able to tell you whether your existing system will work with solar.
What type of system should I buy?
In all my readings, it seems that although flat plate collector systems are cheaper, they aren’t as efficient. Evacuated tube panels are extremely efficient collectors, which is particularly useful in cooler climates.
The next thing to consider when shopping for a solar heating system is how much you want to do yourself?
If you’re not at all handy or simply don’t have the time, then there are lots of professional installers that will be willing to sort out the best system for you.
If you’re somewhat handy and have a little time (but not a lot) then you can essentially buy the whole kit and caboodle, such as a 400 litre solar water heater system, which comes with the tank for just under $4,000, or go for a DIY installation kit for about $2,200 that has tech service available, but no tank .
If you’re more confident in your DIY abilities, then you can buy a 20-tube vacuum tube collector for about $695 and plumb in your solar hot water system yourself. If you want to heat the air in your home, you can get a solar air heating roof mount for about $1,300 and install it yourself.
Finally, if you are a true guru, you can build your own solar collector (water or air) and there are plenty of DIY videos on how to do this. I was particularly fond of the one below, which shows a solar heating system built using aluminum cans and used to heat an outbuilding that otherwise wouldn’t have any heat. This would make a great DIY project! Of course, you have to do a lot of drinking first, but perhaps you could wrangle some friends into helping contribute to that part of the project.