Thermal Imaging and Blower Door Testing

While adequate air exchange is essential for health and safety, many older log homes have a far higher rate of air exchange than is necessary. This is often due to poor design and/or construction which allow air leakage from the inside or outside of the building, but log homes are additionally prone to settling, seasonal expansion and contraction of the logs, and other factors that can cause log joints to move over time. Given that the typical 30 x 40 log home can easily have more than a linear half mile of log-on-log surface area, determining leakage pathways is often complex and extremely difficult to visualize; leaving log home owners no other choice than to apply a sealant to all log joints in hopes of locating and correcting the problem areas.

energyaudit1To identify areas of energy waste, infrared imaging has quickly become a valued tool in identifying problems related to energy loss, water and insect infiltration, inefficient HVAC systems and much more. A thermal imaging camera identifies patterns of heat loss that are invisible to the naked eye and quickly indicates the air leaks within the log home with measurement data that can easily be compiled into a written report. Professional log home applicators are using leading-edge infrared technology coupled with a computer controlled blower door to depressurize the home to an industry standard of -50 pascals, which simulates a 20 mph wind blowing on all four sides of the structure simultaneously. As air is drawn through failed log joints the temperature of the log surfaces changes, producing a thermal image that can be recorded. This allows the applicator to accurately identify and repair the problem areas to stop the energy loss immediately.

Wayne Bell, owner of Log Home Care, uses this technology and reports: “Thermal imaging provides both an immediate cost benefit from the reduction in labor required to seal the home and future savings on energy costs. The computerized blower door provides information about air exchange within the structure, expressed in square inches, which can easily be understood when expressed in terms of an open door or window. The home featured in these photos indicated an open surface area of 66.5 square inches which equates to a 24” wide window being left open nearly 3” but many log homes exhibit air exchange rates several times higher.”energyaudit2

“Don’t confuse this equipment with the inexpensive infrared thermometers sold at home improvement stores," Bell clarifies. "Advances in technology have reduced the prices of this equipment but it still represents a major financial investment for the applicator. Prices vary by applicator but homeowners can expect to spend several hundred dollars for blower door testing and thermal imaging services, but a portion of that charge is rebated back as a credit to the homeowner if our firm does the sealant work", says Bell. “Whether we simply provide a printed report that illustrates what needs to be done or we handle the entire process of applying sealant to the home, our company couldn’t be happier with Perma-Chink Systems products. When dealing with log joints that may allow for both air and water infiltration we use Energy Seal and backer rod on the outside of the structure. If the joint is leaking air but there is little risk of water infiltration, we can alternately use Check Mate 2 (often the clear color) in the interior if needed, but our preference is to do our sealant work on the exterior surfaces. By reducing air leakage, the homeowner obtains a better level of comfort in their log home and Perma-Chink Systems provides the products to make that possible.”

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