Easily installed solar units can also be unobtrusive


August 28, 1993|By James Dulley | James Dulley,Contributing Writer

Q: I want to install a simple solar system to heat our hot water. Are there any new types of small solar systems that won't look ugly on my roof and are easy to install?

A: There are new designs of solar systems that are simple to install and are not ugly. Installing one yourself can cut your annual water heating costs by as much as $200 and can easily pay back its cost several times over its lifetime.

One of the simplest designs uses the coffee percolator concept. This eliminates the need for an electric pump to circulate the solar-heated water. It uses your existing water heater.

Specially designed tubes in the flat collector on your roof cause a water/alcohol solution to boil. As the bubbles rise, they carry the solar-heated solution with them. This is how a coffee percolator works.

This heated water/alcohol solution flows through a sealed heat exchanger base that you set your water heater on top of. Since the heat exchanger gets hot, the water from your water heater naturally circulates through it (hot water is less dense) without any pumps.

This solar system is very simple to install yourself. The water/alcohol solution also provides for winter freeze protection for year-round use.

Another system also needs no pumps. This uses a small concentrating collector. The reflective collector focuses the sun's heat on a small pipe in its center. For super high efficiency, it has an automatic sun sensor to rotate the collector to follow the sun's path all day.

The water gets hot enough to form steam inside the pipe. This creates a slight pressure that forces the steam through an insulated tube to a heat exchanger in your water heater.

There it gives off its heat to the water heater, and the steam condenses to pure distilled water. You can store this pure water for drinking and cooking. Combining the hot water savings and the savings from not buying bottled water, the return on the investment is good.

If you are really concerned about the appearance of the solar collectors on your roof, there is a new type of shallow solar collector that is designed to look like a skylight on your roof. It fits flush against your roof surface and is less than 2 1/2 inches deep. It has durable plastic tubes inside to handle year-round temperature extremes and it is efficient.

You can write to me (6906 Royalgreen Dr., Cincinnati, Ohio 45244) for Utility Bills Update No. 608 listing manufacturers of all types of solar water heating systems, prices and information on the above three new solar systems, and a hot water usage chart to determine the size you need. Please include $1.50 and a self-addressed business-size envelope.

Q: I always hear the size of electric motors described in horsepower, like my half horsepower air-conditioner blower. How much is 1 horsepower and how does it relate to other electric appliances?

A: One horsepower of energy is equivalent to 746 watts of electricity or 2,545 Btu of heat per hour. The amount of electricity your furnace blower draws is not constant. As the load on the motor increases, so does the electricity usage, even though the motor is rated at 1/2 horsepower.

A typical hand-held hair blower dryer uses the equivalent of 1 1/2 horsepower. Two hair dryers consume as much energy as the output of many gas-powered lawn mowers.

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