Weathering A Weatherization Project :: Energy Efficiency Monograph Series

Low Cost Energy Savings With A Big ROI

One of the most cost effective energy efficiency measures is controlling unwanted air infiltration through caulking and sealing.  Caulking and sealing the building envelope of your facility allows you to minimize unwanted air flow through cracks and holes in walls (particularly around windows and doors), ceilings, and floors. An inadequately sealed building not only causes uncomfortable drafts for occupants, the building uses 25-35% more energy to maintain appropriate temperatures.  As an added benefit,  when caulking and sealing is properly performed, it can reduce the amount of dust and dirt that enters a building that causes indoor air quality.

Draft Detective

In order for air infiltration and leakage to be properly addressed, first determine the source.  The areas at joints where different materials meet are the usual suspects for air infiltration issues. Examples of these areas are where the building foundation meets walls, where walls meets floors, or where wood siding meets brick or stone. Other common trouble areas include: areas around ventilation systems, outdoor faucets, cable and phones lines, electric and gas lines, and of course the most common area for air infiltration – around windows and doors.

Hiring an experienced technician to assess the air infiltration issues in your facility can pay huge dividends.   Experienced technicians usually perform what is known as a blower door test, which allows the technician identify issues regarding air leakage, infiltration, moisture condensation, and air quality.  A blower door test depressurizes a facility by using a powerful frame-mounted fan.  Positioned on an outside door, it then gauges and quantifies the air pressure differential and amount of air flowing in and out of a facility.   The fan essentially draws all of the air outside of the home, lowering the pressure inside the facility and causing the higher pressure outside air to come in through any leaks.  Air leaks can then be detected by using a smoke pencil, and remedied with caulk, sealant, and other measures.

Let’s Talk Caulk

Caulks and sealants are comprised of a number of materials such as polyurethane, polysulfide, acrylic and silicone.   All act as barriers that prevent water penetration, allow thermal insulation, and protect against the penetration of other items ranging from unwanted dust to noise.  One main difference between construction caulk and a silicone sealant is that construction caulk is applied in places where movement is not expected to occur between the joints being sealed.  On the other hand, a silicone sealant is usually made of an elastomeric material that allows movement to occur between the joint.  Most construction caulks are usually able to be painted with a wider variety of painting products whereas silicone sealants are typically not able to be painted except with special oil and water based paints products.

Sweeping and Stripping

One way to stop the unwanted warm or cold air from getting into a facility is through the installation of a door sweep. Another easy way is through proper installation of weather stripping around the perimeter of the door.  One last thing to keep in mind: interior doors also serve an insulation barrier, allowing an occupied area of a building to be heated or cooled while preventing heat loss into an unoccupied area.  A well insulated interior door used to cordon off an unoccupied space can be a huge saver when it comes time to pay the utility bill.