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Envelope Sealing

The building envelope1 is comprised of the roof, walls, windows, doors, and floors. By sealing air leaks and adding insulation you can improve the comfort and energy efficiency of your building. Drafts felt during the colder months are usually the result of unsealed spaces between the interior and exterior of a building. During the summer months those same unsealed spaces allow the conditioned air to escape to the outside. Air leakage and improperly installed insulation can waste over 20% of the energy used to heat and cool your building.

Increasing insulation levels and reducing air leakage, will not only reduce the amount of energy your current HVAC system uses, but when the time comes to replace your equipment a smaller; more efficient; and less costly system will be needed.

Blower Door Test

By using a fan to lower the inside air pressure of a building it is possible to determine the air infiltration rate through unsealed cracks and openings. Energy modeling software uses this information to calculate the building’s convective heat loss. This process is generally used on residences but can be used on small commercial buildings.

Window Replacement

The Solar Heat Gain Coefficient or SHGC of a window or door is the percentage of radiant heat that penetrates the glass. The lower a window’s SHGC, the less solar heat it transmits. Solar heat gain can provide free heat in the winter but can lead to overheating in the summer. By taking into account the climate, orientation, and shading conditions the solar heat gain can be balanced with windows having an appropriate SHGC.

Insulation

This is the best defense against heat loss and heat gain through your building envelope. Wall, ceiling and subfloor insulation comes in many forms, making installation easy and cost-effective in all types of buildings. The most common types of insulation are fiberglass batts, blow-in fiberglass, cellulose, rigid board, and spray foam.

In addition to the typical insulation, radiant barriers can be added to attics to reduce summer heat gain. The radiant barrier material is made of a heavyweight foil and works by reflecting the infrared energy away from the structure.

Caulk

Caulk is a flexible sealant used to fill gaps and cracks that allow air infiltration. Eventually all buildings will need to replace or refresh their existing caulking. It is also the least expensive means of reducing your energy bill by as much as 10%. Preventing moisture and bugs from entering the building are added benefits.

Weather-stripping

Weather-stripping around doors and windows reduces drafts and increases the efficiency of the building. On a typical 36 inch exterior door a quarter inch gap can leak as much air as a nine square inch hole in the wall. Weather stripping comes in a variety of forms to fit every application, including door thresholds, wall outlets, tubular gaskets, adhesive-backed foam or tape, and V-strips, to name just a few.

Cool Roofs

A cool roof can help building owners save money by reducing energy bills and the roof operating temperature, which may extend the service life of the roof. Just as wearing light-colored clothing can keep you cooler, cool roofs reflect solar rays to lower roof temperatures. The temperature of a traditional dark roof can reach a temperature of 150º F. However, under the same conditions a cool roof can stay more than 50º cooler.

Environmental benefits include the reduction of local air temperatures, which improves air quality; peak electric power demand which helps prevent power outages; and power plant emissions.

1U.S. DEPARTMENT OF Energy – Energy Efficiency & Renewable Energy

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