AIR LEAKAGE Close the door against heat loss YOU MAY think of doors only as something through which family, friends and the occasional door- to-door salesperson come and go. The truth is that a leaky, ineffi- cient door also lets cold air into your home, while allowing heated air to escape. To reduce this energy loss, you can make the existing door more efficient, or replace it with an energy-efficient model. Doors lose heat through conduc- tion’ and air leakage. Conduction allows heat to pass through the material of the door. A material’s ability , to resist conductive heat loss is known as thermal resistance and is measured in RSI (metric) or R (imperial) units. Single-glazed patio doors with metal frames offer the lowest thermal’ resistance, usually in the range of RSE 0.16 (R.0.89). At the ‘ other end of. the scale are steel doors insulated with polyurethane at RSI 2.56 (R- 14). Solid wood doors typically have thermal resistance values of RSt 0.40 (R 2.25); * Storm doors are available ira wide variety of materials, izes and styles and can provide added pro- .tection against heat loss. Wooden and insulated units typically have the highest thermal resistance. Homeowners can purchase con- vertible storm doors equipped with a glass insert for winter use and a screen insert for milder weather, or units that contain both an adjust- able glass pane and a screen for year-round use. If you decide to replace a door, consider an insulated unit. These doors are filled with a light plastic, high-density insulation that pro- vides a much higher thermal resistance than found in conven- tional doors. Insulated doors are also more expensive but their energy efficiency can make the ex- tra cost worthwhile. The best choice for new unin- sulated doors is solid wood. For energy efficiency, purchase doors with minimal glass (make sure it’s double glazed), unless the door is . to be situated in a south-facing wall, where it can provide passive solar heat gain. Double-glazed patio doors offer significantly higher thermal resistance than single-glazed units. Similarly, wooden-framed doors are preferable to metal-framed units (if you buy the latter, make sure it incorgerates a thermal break to reduce heat loss). See Doubie Page 26 LUXURY — RENOVATIONS BATHROOMS and KITCHENS —— = Estimates 987-3055 Showroom 153 W. 3rd SON ¥. SAVINGS SAVE $249 on High Resolution 28” ‘KV2781R Save $200 on Sony Handycam. t T.V. with stand 1425 MARIN EDR WEST JAN. 25 - Friday, March 13, 1987 - North Shore News NEED MORE SPACE? CALL US FIRST... ‘and look at a Hollyburn Sunroom. For a fast, problem free and beautiful addition to your home, call today to visit our showroom. 682-7177 Evenings 734-9741 Woltybur Sunrooms beige or r ees! ‘al ; : valance and.