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| Could you heat and cool
your 2,300 square-foot home for $17.31 a month? Believe it or not, First Electric
Cooperative members Allen and Alice Carter are doing just that. Fifteen years ago they
began building their home in the Kentucky community of Saline County that would be
energy-efficient even into their retirement years. The Carters had no idea what heating and cooling costs would be when they began building. They knew one thing - to keep costs low, they had to plan ahead. They sought suggestions from reference books and from a friend who was in the heating and cooling business. When building any home, there are three components to make a home energy efficient: the house envelope, duct work and heating and cooling equipment. With these three components in mind the Carters began the construction of their dream home.
The house envelope includes the walls, ceilings, floor, windows and air infiltration. The walls of the Carter home are 2x6 rough-cut lumber. They cut their own trees and had the lumber cut for their house. With 2x6 walls and blown cellulose insulation, they had R-22 walls on three sides of the house. The north wall of concrete is earth-sheltered and is also insulated. So very little heat is gained or lost through the walls. The ceiling has R-38 blown cellulose insulation and the trusses are cantilevered. This design allows full depth of the ceiling insulation to extend over the exterior walls. A conventional truss sits on top of the wall and doesn't allow space for insulation. The floor of the house is a concrete slab with perimeter insulation to reduce the heat gain and loss around the perimeter. All the exterior doors are metal insulated, which have a higher R-value than wooden doors. |
The windows are double-pane with storm windows. The house is also designed for passive solar heating. An overhang shades the windows on the south from the sun during the summer, but allows the sun to enter in the winter. To stop air infiltration through holes or cracks in the envelope of the house, and thereby further reduce heating and cooling costs, the Carters caulked around windows and doors. The ductwork, another important component of an energy-efficient home, may determine if your house will be comfortable both in winter and summer. The ductwork transfers the conditioned air to the rooms of the house. The Carters used duct board that was sealed properly with no leaks and insulated to at least R-6. Without an airtight duct system and proper insulation, you could be loosing conditioned air before it reached the rooms. In that case you could have hot rooms during the summer and cold rooms during the winter. So proper duct sealing and insulation can mean great savings. Proper sealing can be done by using mastic, which is a paste that is applied at the joints and connections. The third component of an energy-efficient house is the heating and cooling system. The Carters installed a geothermal heat pump. The Carters built a one-acre pond next to their home, so that the pond's water could be used as the heat exchanger. They had over 1500 feet of coiled pipe placed in the bottom of the pond. An antifreeze solution is pumped through the coiled pipe and back to the 2 1/2 ton heat-pump unit in the house. A refrigerant transfers the heat from the water to a coil. Air blowing across the coil absorbs or disperses heat, depending on the time of year. During summer, heat is absorbed in the coil and transferred back to the solution in the pipe and dispersed to the pond. In winter, the process is reversed. Heat is absorbed from the pond and moved to the heat-pump unit and distributed throughout the house via the ductwork. The Carters also receive a bonus from the heat pump system in the form of free hot water. When the heat pump is operating, excess heat from the system heats the water for household use. The Carter's' geothermal system was installed in August 1991. The heating and cooling contractor, Mike Jones of Hydro-Temp Corporation of Pocahontas, Arkansas installed an electric meter on the system to track electricity use. For the past 8 years, the Carter's' monthly heating and cooling costs have averaged $17.31. This may be hard to believe, but proves that when you build an energy-efficient home, you can expect to save a substantial amount on heating and cooling. If you would like more information about making your home more energy efficient, contact your local First Electric Cooperative office and ask for the Members Services Department. |
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