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Today's

TECHNOLOGY AND YOU

Letting
the
sunshine in

Q: I want to add an efficient sunroom to my house for casual living area and for starting plants. My budget is limited. Are there do-it-yourself sunroom kits that will also lower my heating bills in the winter.? - H. W.

A: There are many new designs and styles of do-it-yourself sunroom kits available for even the inexperienced handyman. Some manufacturers offer more than 140 standard kit sizes with many options like screening, vents, efficient fans, multiple doors, movable shading, etc.

Many of the new do-it-yourself sunroom kits literally bolt together like huge erector sets. All parts are precut, predrilled and color-coded. They include instructional videotapes and all the required screws (rustproof stainless steel), seals, etc. Once the ground area is prepared, one can be erected over a weekend.

Although some of the standard new sunroom kits are very efficient and can help heat your home in mildly cool weather, most will not significantly heat your house in the winter. Most likely, they will require supplemental electric heat, either from your central furnace, heat pump or from small space heaters.

It is possible to modify a standard sunroom design to provide a significant amount of heat in the winter without overheating in the summer. The key to annual net positive energy flow from a sunroom is adequate thermal storage in the floors and walls, movable insulation and an air distribution method to get the heat into your house.

The least expensive kits use aluminum extrusion frame members and special double-pane clear plastic glazing. It is shatterproof and ultraviolet (UV) stabilized to resist the sun's damaging rays. Clear acrylic or super-tough polycarbonate (bulletproof glass) is often used. This produces a lightweight, yet strong, sunroom.

Many of these lightweight kits are designed to be built right over an existing deck. Check your local building codes first to make sure this is acceptable in your area.

One convertible (to a porch) sunroom kit has quick-change clear acrylic plastic thermal window panels that snap out to expose screens. This creates a summer porch. These lightweight panels are sized to store neatly behind the lower clear plastic panels. There are built-in flip up roof vents to create a natural comfortable breeze throughout the sunroom/porch.

The frame material has a great impact on the aesthetics and energy efficiency. Extruded aluminum is strong and simple to assemble. In all but the mildest climates, choose only an aluminum frame with plastic indoor-to-outdoor thermal breaks. This saves electricity and blocks condensation.

Wood framing is more expensive, but it is attractive and offers more design flexibility. Wood is also a better natural insulator. A curved eave (curved transition between the front and roof) is especially attractive. The glass is also curved with no seams for an unobstructed view outdoors.

One new sunroom kit, by SunRoom Design, uses an aluminum exterior frame which is covered with a heavy natural oak wood veneer on the interior. This unique design uses super-strong interlocking wood/aluminum joints instead of adhesives. With the high humidity from plants in most sunrooms, veneer attached with only adhesives can sometimes delaminate.

The type of glazing is most important for an efficient comfortable sunroom. Clear or tinted double-pane, low-e argon or Heat Mirror glass is most efficient. Double-pane crystal clear acrylic plastic is also effective. If you plan to use your sunroom just for starting plants, single pane glazing is adequate and less expensive.

One unique sunroom option is a semicircular design, Sun Crescent. It is actually a huge five-sided walk out bay window. It assembles easily and adds openness to any room.

During the summer, adding afternoon shading can increase comfort. Several kits have built-in frame channels to hold sun-blocking screens or shades. Some use manual crank screens or shades. Others have motorized shades that can be controlled by automatic sun and temperature sensors.

Write for Utility Bills Update No. 764 showing a buyer's guide of 14 sunroom kit manufacturers and accessories listing designs, styles, frame types, glazing options, ventilation and shading options, prices, materials heat capacity chart and a greenhouse plant selector guide. Please include $2.00 (with checks payable to: "Jim Dulley") and business-size SASE, and send to Jim Dulley, Illinois Country Living, P.O. Box 3787, Springfield, IL 62708.

James Dulley is a mechanical engineer who writes on a wide variety of energy and utility topics. His column appears in a large number of daily newspapers.

6 ILLINOIS COUNTRY LIVING • SEPTEMBER 1996