Most homes waste huge amounts of energy.
by Janice and Jonathan Waterworth —
An energy audit is an inspection and analysis of the energy consumption and in a building, indicating, ultimately, how and where that building can reduce energy consumption and save costs.
A professional energy audit involves various characteristics of a home’s building envelope including the walls, ceilings, floors, doors, windows and skylights. Each of these components is analyzed and the resistance to heat flow (R-value) is measured or estimated. The performance of mechanical systems such as heating, ventilating, A/C units and water heaters are analyzed for performance and tested for gas leaks.
Blower door testing will assess a home’s air leakage and pressure balance. It is critical for a home to maintain a balanced pressure to the outdoors to prevent it from “sucking” unconditioned air indoors or pushing conditioned air outdoors. Either imbalance will lead to lost energy and cost you money. A seemingly small 15 percent leak in your attic’s return ducting that is 115 degrees F reduces your air conditioning effectiveness by 50 percent.
Thermal imaging within the building envelope can help pinpoint potential issues by identifying heat transfer through convection, conduction and radiation. This identifies some of the most common failures in a building envelope, including insulation and air delivery systems.
Why should your home get an energy audit?
Getting an energy audit just makes plain sense and cents. Most homes waste huge amounts of energy. Just a 5 percent misplacement of attic insulation reduces your overall attic R-value by half. A10 percent misplacement means that your overall attic R-value is only 25 percent effective.
In addition, there are many government, utility company, and citywide tax incentives and rebates for energy audits and home energy efficiency improvements. But you must act now, because these incentives are temporary and will not last long. Start saving money today.
What should I expect?
The energy auditor will analyze all of your home’s energy systems and building envelope. He will test for gas leaks in your mechanical equipment and for radon levels. An analysis of your last 12 energy bills will indicate your home’s energy profile and show the potential savings. The energy bill history from the local utility company can be calibrated using heating degree day and cooling degree day data obtained from recent, local weather data in combination with the thermal energy model of the building.
All of the information collected about your home is further analyzed by advanced software, which generates a comprehensive report estimating energy savings and the impact of suggested improvements per year. It will identify many cost effective ways to improve the comfort and efficiency of your home.
Why we need to reduce energy consumption
The most obvious answer is to save money — we all want to do that. But by making home energy improvements, we will also make our homes more comfortable and reduce our dependence on non-American companies and governments. Some 40 percent of all energy used in this country goes to buildings and homes, mostly in the form of heating, cooling and lighting. Less energy consumption is obviously good for the environment, but it also means less money out of your pocket.
Jonathan Waterworth is a licensed general contractor who is both LEED certified and BPI (Building Performance Institute) accredited. Southwest Sustainable Structures treats homes as integrated energy delivery systems and pinpoints in-home energy deficiencies and air quality challenges. 480-471-0111 or www.azenergyefficienthome.com.
Reprinted from AzNetNews, Volume 29, Number 3, June 2010.
August 14, 2012
Environment, Health, Home and Garden, Money and Financial