AIR INFILTRATION SEALING
In our hot and humid Climate Zone 2 stopping air infiltration can play a much larger role in reducing energy bills. Air infiltration greatly increases our cooling and heating costs by allowing outside air to easily flow into and out of the home. Outdoor air that leaks indoor makes it difficult to maintain comfort and energy efficiency. In addition, studies performed by the Department of Energy’s Energy Star Program demonstrates that air leakage accounts for 25–40% of the energy used for heating and cooling in a typical home. Through years of testing homes for air leakage and performing recommended air-sealing strategies many of EnviroGreen’s clients have experienced savings that have almost cut their summer bills in half.
Why can air infiltration make up such a large amount of the energy costs in your home? Our climate zone introduces additional challenges that the majority of the homes in the United States do not experience… high humidity. Moisture, or high relative humidity, intensifies the negative results of air infiltration as it introduces a much higher energy demand – or “energy load” – than does dry air alone. Cooling the air in your home during the summer time or heating this air to warm your home in the winter uses a relatively small amount of energy in most dryer climates. However, in our environment, dehumidifying (removing moisture from the air) while cooling or heating the air in our homes poses a much larger monthly heating/cooling penalty because moisture (water particles) contains a greater amount of energy. Also, when we have difficulty cooling or heating our home many of us tend to want to purchase a larger air-conditioning and heating system which, in turn, uses even more energy. It can become a viscous cycle that causes us to keep buying more or larger mechanical items while spending more money operating them. In many drafty homes in the Greater New Orleans Area cooling or heating is far less of a problem than is simply dehumidifying the interior air to help us feel comfortable when inside.
A famous 2004 Building Science Corporation study demonstrated that in most cold climates, over an entire heating season, 1/3 of a quart of water can be collected by diffusion through typical sheetrock without a vapor retarder but 30 quarts of water can be collected through air leakage from only a 1 inch square hole. Imagine how much water vapor (moisture) is coming in through our cracks and holes in our homes during our air-conditioning season in our humid climate zone.
This moisture is responsible for a vast array of building failure including structural damage, rot, mold, mildew and poor indoor air quality. Of all the environmental conditions, moisture poses the biggest threat to structural integrity and durability, accounting for up to 89% of damage in building envelopes.
Moisture enters buildings from the outside. Moisture comes into a building by infiltrating (mass movement) through doors, windows, cracks, and other openings to the outside world. About 95% of the moisture entering a building enters through air infiltration. Only 5% of the moisture enters by diffusion through building materials. A high concen- tration of water vapor on the outside of a building forces it through walls into drier inside air. Click here to read the rest
Solutions and Benefits
As an Energy Star Partner, and long lasting members of RESNET and BPI, the owners of EnviroGreen have been testing houses for air infiltration and duct leakage and providing energy efficiency consulting and planning for over ten years on homes ranging from new construction to old historic New Orleans masterpieces. Without testing a home’s infiltration rate and performing a visual inspection, sometimes with the aid of infrared photography, the problems of high energy bills and/or moisture and discomfort can not be diagnosed properly.
After the causes of a home’s energy efficiency or indoor air quality problems have been properly diagnosed EnviroGreen will set forth a plan of attack and list the necessary improvements in order or their cost effectiveness while putting health and safety items first on the list.
Experts have agreed for years that even simple air sealing through caulking, weatherstripping and spot-foaming – very basic weatherization techniques – when done properly, can play a major role in solving a home’s energy and and air quality problems.
Are there financial incentives?
Yes, if the home being insulated is an existing structure in Orleans Parish (Eastbank and Westbank), EnviroGreen, one of the original founding contractors of the New Orleans Energy Smart Energy Savings Program, offers rebates to homeowners or renters of up to $1,000 for reducing the air infiltration of the home and up to an additional $1,000 for sealing ductwork to below 10% leakage.
These rebates to the homeowner can be used in conjunction with discounts provided by EnviroGreen through the New Orleans Energy Smart Program and federal energy efficiency tax credits.