My husband and I have the plans for "Water Heater Helper" by Bert B Blanton of Info Works. The plans seem very doable for setting up a hot water system for our house, but we are stumped by what to do in the winter when we get into freezing temperatures. The plans were developed in Southern California, not for the reality of Iowa. What are some techniques for dealing with cold weather and a solar water heater, located on the south side of a house, exposed to the cruelity of winter? Any ideas, chores (drain it each night?), or techniques would be appreciated. Thank you.

-- Kathy (redfernfarm@lisco.com), October 16, 1999

Answers

You have two choices.

Build your solar heat exchanger so it operates with water running through the system. This is what I did. It requires you to drain down the system in the winter time. Be sure to organize it all so a complete draindown occurs. I use a heat exchanger in the firebox of my wood cookstove in the winter time. Both systems are interconnected to one hot water tank and are separate legs of the same system.

The alternative is to design a more complicated system so you are circulating antifreeze through the solar system. The hot solution must then be recirculated through a heat exchanger to extract the heat and make hot water. I found such a system too cumbersome to build and frankly more trouble to work with than the simpler two legged system.

-- Nick (nikoda@pdqnet.com), October 16, 1999.

There are also active systems which pump water through the panel only when it's hot enough to heat the water. When the pump isn't running, the water drains down out of the panels. Pretty foolproof. But expensive.

The passive system you describe sounds similar to the ones I make; I drain them for the winter, and use another form of energy for my wintertime hot water. Most the solar power available is summer time anyway, so it's not that big a deal. Also, I recommend installing a little gizmo called a "heat plug" (I think that's what it's called). This is a little plug with three receptacles, which activates the receptacles when the temperature gets down to 40 degrees. Plug in a small light bulb, and voila, you have a bit of insurance against freezing the system when an early hard freeze catches you off guard.

-- jumpoff joe (jumpoff@echoweb.net), January 11, 2000.