Each part of a home or other structure interacts with the other parts in examining how the home uses energy. This a holistic approach to the home. Since I come from a health care background, holistic healthcare is very familiar to me. Other HERS Raters, Thermographers and Building Scientists call it a “Whole House Approach”! The name is less important then the philosophy. Consider how things work together and what happens elsewhere when you change something.
Physical Laws that we learned in science class or on the college level in various physics classes apply to energy use in any structure. All buildings are designed to provide shelter from the elements. Heat or cold, moisture in the form of rain, snow or humidity, and pressure of air movement, such as wind, or other naturally occurring pressures all interact together.
The 2nd Law of Thermodynamics tells us the Heat moves from Hot to Cold. Various other parts of science show that moisture moves from wet to dry; and that pressure moves from High to Low. The movement of heat from hot to cold can cause much of the movement of moisture and pressure that we observe in a home.
When I make recommendations about changes to the insulation or air sealing or equipment, how that change effects other parts of the home is an important consideration.
I get calls for two reasons.
• A homeowner or builder wants recommendations to save energy and thus money on energy bills.
• A homeowner has a room or rooms that are drafty or otherwise uncomfortable.
I make recommendations for comfort and for saving some money. Recommendations about insulation levels, air sealing and other improvements may be related to saving energy. They may be more related to comfort. Sometimes we can work on improving comfort and save a few dollars a year in the process. Sometimes the improvements are based more on saving energy.
In the Wichita area, electricity currently sells for about 11¢ per KWH. Compare that to an area with primarily hydroelectric power such as the Columbia River Valley between Oregon and Washington or the Tennessee River Valley. Electricity in those areas will sell for closer to 7¢ per KWH. If you go to Maine, you can find prices of 17¢ per KWH. The improvements that make financial sense to people in Wichita, might not in an area with lower energy prices. In an area with higher energy prices, financial sense might be to do more.
This means that over time, improvements may make more sense financially as energy prices increase. I will consider the relative timing of different improvements, what gets done first and then second, in my recommendations. I will also consider the cost of material compared to labor. Many of the simple cost effective improvements to save energy involve mostly labor costs and relatively smaller material costs. If the cost of labor is covered to install more material, it may be worth doing, even though at current prices it is not really cost effective. We can discuss this in much more detail when reviewing the reports.