GETTING BY WITHOUT CFA's

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

Common insulation materials are listed in Table 2. You can see that most rigid insulation boards are produced with CFCs, including urethane, polyisocyanurate, phenolic foam, and extruded polystyrene. Foam-in-place urethane insulation is also produced with CFCs. The only insulation-board materials that don't contain CFCs are expanded polystyrene (commonly called EPS or beadboard) and rigid fiberglass. Batt and loose-fill insulation materials such as fiberglass, rock wool, cellulose, and perlite don't contain CFCs.

The distinction between extruded polystyrene and EPS needs clarification. Both have the same chemical base (styrene), but production differs. With EPS, tiny beads of styrene are mixed with pentane and are expanded (much like popcorn), The expanded beads are molded into large blocks that are then sawn into boardstock. With extruded polystyrene, on the other hand, the styrene is mixed with CFC-12 and injected in an extruding machine. The CFC expands the sty rene in one continuous board rather than in separate beads. Extruded polystyrene generally has higher density, greater compressive strength, and higher R-value.

Alternatives to CFC-containinginsulation are on the way but will be more expensive.

To attain high energy efficiency in homes without using CFC-containing insulation requires building thicker walls. Instead of using 2 X 4s, for example, framing can be done with 2 X 6s (or, for super-insulated buildings, 2 X 8s or double 2 X 4s), and the foam sheathing eliminated. Even though the walls will be thicker than a comparably insulated house with CFC-foam insulation, the cost is often lower because fiberglass and cellulose insulation are less expensive than rigid foam.

If you want to use rigid insulation, stick with expanded polystyrene or rigid fiberglass. EPS is produced in dozens of factories around the country, though it isn't readily available in building supply centers. When ordering EPS, you can usually specify a higher-density product that will insulate better and provide greater compressive strength, though the cost will also be higher. Rigid fiberglass for wall sheathing, unfortunately, is not readily available in this country, though a few companies import a product from Canada.

Within several years, the foam insulation industry expects to have eliminated CFCs from all foam insulation. Making that change is easier with some products than with others. With extruded polystyrene, the change is relatively easy. In fact, Dow Chemical, the manufacturer of Styrofoam-brand extruded polystyrene, has begun shifting plants over from a process using CFC-12 to one using a less ozone-destructive HCFC foaming agent that is commercially available. Doug Draper, a spokesman for the company, said Dow has already converted two of their six U.S. plants and expects to complete all conversions by mid-1990.

RSS | Comments | E-mail | Print