Go Solar! Get Solar Hot Water from a Kit

The Sunward solar hot water kit is a proven system that takes most of the guess work out of setting up a solar water heater — and might even give you additional storage space!


| December 2010/January 2011



solar hot water - finished shed

When finished, collectors for the solar hot water were mounted on a shed located away from the house.


PHOTO: BRYAN WELCH

When the "Go Solar!" battle cry first went up decades ago, handy folks with a knack for plumbing and carpentry put their skills to work designing custom systems that fit their precise solar vision. That adventure — of creating and installing cutting-edge energy technology — remains a draw for some homeowners today. The rest of us would rather skip the adventure and opt for a proven system, such as the Sunward solar hot water kit that Country Home Products offers. With factory mounts and prefabricated components, this kit will allow you to enjoy long, hot, and solar-powered showers in just a few weeks — without the challenges of designing and building a system from scratch. If you’d like some expert help with installation, you can even hire a certified installer.

The solar collectors of the new Sunward system capture heat and transfer it to glycol-filled tubes. The glycol then circulates through a heat exchanger in the hot water storage tank. Some systems use water to carry heat from the collectors, but water would freeze in winter in some climates unless there were a mechanism to drain it each time the temperature fell below freezing. A glycol-based system can be used in a wider range of climates.

Country Home Products designed its Sunward system for versatile installation, too. Customers can choose to mount the collectors on the roof or on a ground-based frame. The roof-mounted frame lies flush with your roof, so you’ll need a south-facing slope, and your collectors will likely be a little less efficient than they would be on a ground-mounted frame (unless you have a steep roof ). The closer the angle of the roof matches the angle of the sun, the more effective the system will be.

If you want to mount your collectors in a frame, you have a choice between a weatherproof steel rack and a timber frame rack. We chose the timber frame option and enclosed it as a shed.

The first thing you’ll notice when the truck delivers your Sunward system is that it’s big. Packed on a wooden pallet about 9 feet long with a 4-foot-tall backstop, it can’t be safely unloaded in one piece. Pretty much everything you’ll need comes in the package, including the collectors, heat exchanger, mounting hardware, framing, connectors, and glycol. To protect the components, make sure to tell the delivery driver to disassemble the package and unload the components one at a time. Even with a pallet loader, the huge package is unwieldy. After it’s on the ground, you’re ready to start the installation.

How the Solar Hot Water System Works

The most complicated aspect of the system is probably circulating the hot glycol between your house and the collector. Like many solar hot water systems, Sunward’s system is designed to supplement your existing water heater, so the heat exchanger and the 80-gallon hot water tank that comes with the kit need to be located near your existing water heater and tied into the existing tank. If you’ve chosen a roof-mounted collector, this means you’ll need to run glycol lines to the tank through the roof and the house. If you go with the ground-mounted option, you’ll need to bury tubing from the collector to the storage tank inside your house. Because the lines contain only glycol, you can lay them in a relatively shallow trench without worrying that they’ll freeze. Just be careful next time you plant a tree!

bryan
1/5/2011 2:43:57 PM

If the solar heat exchanger were connected to the main tank, then you would never use non-solar energy to keep the tank warm. As this simple system is configured, you only draw the solar-heated water into the main tank when you are utilizing hot water in the house. If you go very long without running hot water, your conventional tank uses conventional energy to keep that water warm. We turned down our thermostat, which worked while the solar hot water was more than sufficient for the house, but when the short, cloudy days of winter arrived we needed to turn up the hot-water thermostat, which resulted in some unnecessary propane consumption on sunny days when we're not home. If the main tank were hooked to the exchanger, that the solar system would be keeping the water supply warm.


dave m.
1/5/2011 2:15:47 PM

One sentence in this article could use a little more explanation: "The way this off-the-shelf system puts hot water in your pipes is simple, but it’s simple at the expense of efficiency." I take this to mean that this thermosiphon dump from an external heat exchanger into the top of the tank is not efficient? What would be the hot setup (pun intended)? An internal heat exchanger or some kind of pressurized delivery system for the heated water? A little more clarification, please, Bryan.


bryan
12/9/2010 2:53:01 PM

Yes, it would probably be more efficient to put it on the roof. We have a shake roof we didn't want to disturb, that's the long and short of it. So it went in the yard. - Bryan


mark
12/2/2010 10:47:29 AM

I am interested in further exploration of the considerations that went into the author decision to go with an outbuilding mount rather than a roof mount on his house. While the lower pitch of a typical roof is somewhat less effective for winter water heating, it seems like heat losses in the pipe run from outbuilding to home would be much larger than the slight efficiency loss.


farmerboy
11/28/2010 8:26:06 PM

I just finished reading the article. I think this system would be great coupled with a tankless water heater. It would be a little more expensive to start with but you would not use energy to heat the water stored in a standard tank type water heater. I have been a long time subscriber, and look forward to every issue, keep up the great work!


connie kenny
11/18/2010 5:21:55 AM

Here's another way to look at Renewable Energy vs Conventional Energy....You NEVER have a payback with conventional Energy, because if you don't pay the monthly bill (look at it like rent)for your heat, hot water, or electricity you will not recieve it. At least with renewable there will be a time when it WILL be paid back and you don't have to shell out that monthly expenditure.


tam
11/17/2010 2:29:30 PM

I love the concept of ideas like this - but has anyone stopped to do the math on this? Depending on what your specific savings are, it would take anywhere from 13 to 38 years just to get your money back on this system. Until they find a less expensive way to do something like this, it certainly doesn't help the average person.






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