The growth of the home performance and weatherization industry is spearheaded by the Home Performance with ENERGY STAR® program, a joint initiative of the U.S. Department of Energy (DOE) and Environmental Protection Agency (EPA).
These federal initiatives are aided by the American Recovery and Reinvestment Act (ARRA), which is providing significant funding, particularly for weatherization assistance for low-income homes.
Best Practices for Best Results
America’s 130 million existing homes were responsible for 20% percent of total energy consumption in 2008 and 1,270 megatons of greenhouse gas (GHG) emissions.
Although there are many tactics a homeowner or general contractor can employ to improve energy efficiency, those tactics tend to only scratch the surface of the potential in each home. Often an attempt to fix an obvious problem without a complete understanding of the root cause can actually compound performance issues.
Maximizing energy efficiency, durability and occupant comfort, health and safety requires specialist training, equipment and skill. The specialist contractors who have studied home performance use sophisticated diagnostic tools-including pressurization blower doors, infrared (IR) cameras, duct blasters, nanometers and specialized energy analysis software-and building science methodologies to find the root cause of the problems in the house and fix them once and for all.
Prescribed improvements can include air sealing with sealants and caulks, insulation, weather-stripping, fixing duct leaks or servicing an HVAC unit. The difference is putting these often simple steps together in combination-the right combination for the specific problems in the specific house. No two houses have the same exact set of problems.
Energy savings potential is determined by the initial performance level of an individual house. A house that already performs well won’t save much energy after a retrofit compared with a house that is performing poorly at the start of the project.
Deep Energy Retrofits
On average, a home performance retrofit can reduce energy consumption by between 10 and 40%. ‘Deep energy retrofits’ like the ones currently being studied by ACI’s Linda Wigington as part of the Thousand Home Challenge, are designed to reduce energy use by 70 to 90%.
For new homes, an ENERGY STAR qualified house is one that is at least 15% more energy efficient than homes built to the 2004 International Residential Code (IRC), and includes additional energy-saving features that typically make it 20 to 30% more efficient than standard homes.
Non-Energy Benefits of Weatherization
The same measures employed to reduce energy consumption also improve occupant comfort. Home performance contractors report that the vast majority of their customers are motivated by comfort, not energy bills or environmental awareness. Common complaints include rooms that are too hot or too cold, drafts, uncontrollable humidity levels, mold, mildew and indoor air quality. With 40% of all energy use in this country going toward that building sector, it really is significant the amount of energy savings that is possible simply through implementing energy efficient technologies. Many of us spend half of our lives inside buildings. We enjoy the comforts of being not too hot or cold regardless of the outside weather conditions. We also enjoy being able to breathe clean healthy air. This indoor comfort comes at a cost. By implementing better building practices and weatherization retrofits, our nation could reduce its overall energy use.