QUESTION: Is it possible to build an inexpensive solar water heater ourselves? We can't afford to spend thousands of dollars for a contractor-installed one, but we want to reduce our water heating costs.
ANSWER: The simplest do-it-yourself solar water heating system is the passive breadbox design. It is extremely effective, and with you supplying the labor, it can be built over a weekend for less than $100 in materials, depending upon its size.
In your mild climate, a breadbox solar water heater can be effective year-round. Over the entire year, you can expect it to save up to 50% of your water heating costs. For a large family, it can pay back its cost in less than one year.
A breadbox solar system looks just like its name suggests. It's basically one or two large water tanks mounted inside an insulated wooden box. You cover the top of the box with glass or a clear plastic sheet and tilt it so it faces the sun.
The water tanks, which you should paint flat black, work as both the solar collectors and the storage tanks. You can increase the efficiency of the system by laying shiny aluminum foil around the inside of the box. This reflects the solar heat to the water tank from the back and sides too.
Based on average daily hot water usage, a family of four will need one 80-gallon or two 40-gallon water tanks to be able to supply all its hot water requirements on a sunny summer day.
If you are lucky, you might find discarded water heater tanks for free in a junkyard or at a plumbing supply outlet. You can strip them down and cut the costs. Otherwise, you'll have to buy the water tanks.
To be most effective, you should set up the plumbing to use the breadbox as a preheater for your standard water heater. This means that the cold inlet water line should first run to the breadbox heater, and then back out to your standard water heater.
Once you've made the insulated wooden box, locate it on the ground against the most southern wall of your home. This will minimize the heat loss from both the pipes and the back of the box. Tilt the box so that the glass surface makes an angle from the ground that is equal to the latitude degrees of your area.
You can write to me for Utility Bills Update No. 013 showing simple do-it-yourself instructions, diagram and piping layout for making this solar water heater. Please include $1 and a self-addressed envelope. Send your requests to James Dulley, c/o Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.
Lower Brightness on TV Won't Save Power
Q: I watch a lot of TV at night. Will the amount of electricity it uses be less if I turn down the brightness knob?
A: A large color TV can use a lot of electricity, more than 200 watts, depending upon the type. You can feel the heat given off from the back of your TV, which gives you an idea of how much electricity it uses. Just turning down the brightness a little won't cut your electric bills significantly.
Often, you can still have an excellent TV picture at lower brightness if you use lower wattage light bulbs in your TV room. Better yet, turn off some of the lights. Adding all these wattage savings together over an entire year of TV watching can save quite a bit of electricity.
Fluorescent Lights Not for Bathrooms
Q: We are about to select a new bathroom cabinet. Is there much difference in the electrical usage between fluorescent and incandescent lighting?
A: A fluorescent light uses about one-fourth as much electricity as a standard incandescent light bulb. In many areas of your home, fluorescent lights are the best choice.
In your bathroom, you may be better off with the incandescent light bulbs. Even though incandescent bulbs cost more to operate, they are not switched on very long in a bathroom. For applying cosmetics, the quality of the light is important. Although there are special fluorescent lights made to approximate normal lights, they may not be adequate for you.