Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, August 27, 1995 TAG: 9508290072
SECTION: HOMES PAGE: B1 EDITION: METRO
SOURCE: JAMES DULLEY
DATELINE: LENGTH: Medium
A: The simplest method to stop the intense heat is to install an attic vent fan kit. Adequate attic ventilation can lower the attic temperature by 50 degrees in the hot afternoon sun. Reducing the attic temperature all day lets second-floor bedrooms cool quicker in the evening, too.
A do-it-yourself solar-powered attic vent fan kit is very effective and operates for free. It is simple to install and requires no wiring, so an electrician and professional installation are not needed.
Most solar-powered fans use a small solar cell panel that produces 12 volts of electricity when the sun shines on it. This is ideal for attics. The fan runs fastest and vents the most air when the sun and your attic are hottest.
There are two basic solar attic vent fan designs. One integral design has a solar cell panel built into the top of the fan. The other remote design has a small separate panel which is attached to the fan with a wire. Since it produces only a safe 12 volts, wiring is simple and can be exposed.
The integral design is often installed in the roof near the peak. This exhausts the hottest air from the attic. Integral models are most effective on roofs that face somewhat south and are not shaded.
If your roof is partially shaded or does not face south, install a remote fan kit. For the greatest air flow, mount the solar panel (only 15 inches square) in a sunny spot facing south. The mounting bracket is often included.
For the inexperienced do-it-your-selfer, install the fan in the gable so the shingles are not disturbed. It should take about 30 minutes. For two fans, one on each end of the attic, buy a larger high-output panel.
To keep the solar fan running into the evening to super cool the attic, attach the wires to a standard 12-volt battery, too. The battery will recharge in the daytime. Do-it-yourself battery-power kits are available.
It is important to select a fan of the proper air flow capacity for your house. Solar-powered fans range from 500 to 1,000 cubic feet per minute (cfm) of air flow. Electric (110-volt) models range from 800 to 2,000 cfm.
If the fan is too small it will not adequately cool your house. Installing one that is too large costs more to buy initially and wastes electricity.
For a buyer's guides of 15 solar-powered and standard 110-volt attic vent fan manufacturers listing air flow capacities, sizes, prices, features and a recommended attic/fan sizing chart, write to James Dulley, The Roanoke Times, 6906 Royalgreen Dr., Cincinnati, Ohio 45244. Ask for Update Bulletin No. 801. Please include $2 and business-size self-addressed stamped envelope.
Q: I added a greenhouse on my living room for passive solar heating in the winter. I used pressure treated lumber for most of the exterior. Is it necessary to use a preservative on the wood yearly?
A: The primary purpose of using pressure treated wood is to resist rot. Pressure treated lumber still suffers damage from sun, wind and moisture. Greenhouses are particularly hard on lumber because they typically are humid and are exposed to the sun.
All of the lumber should be treated with a wood sealer/protector, like Thompson's, every two years. Wait a month after building with treated lumber to be sure all the moisture from the treating process has dissipated.
by CNB