HVAC air leakage building inspections - infrared energy audits
In energy audits of homes and other buildings, technicians use blower doors in conjunction with thermal imagers. The blowers create positive or negative pressures within interior envelopes, making leaks much more apparent in thermal images.
For nearly 30 years, the U.S. Department of Energy (DOE) has helped low-income families save energy by "weatherizing" their homes. Called Weatherization Assistance, the program is funded by DOE but administered by individual states. In July of 2005, the DOE announced awards to 19 states for home weatherization totaling $92.5 million. The program's total budget for FY 2005 is $288 million.
Today's Weatherization Assistance Programs include a comprehensive series of energy saving measures based on audits of residential units. They take a "whole-house approach" that includes a wide variety of energy efficiency measures and are leading the way in founding a growing industry that makes energy efficient homes available to everyone.
What to check?
Blower doors consist of a frame and shroud that fit inside doorframes. Mounted in each blower
door is a variable-speed fan that allows it to induce pressure on the inside of a dwelling. Instrumentation that accompanies a blower door includes pressure gauges with which a technician can measure the flow of air through the fan as well as the pressure differential between the living space and the outdoors.
What to look for?
Even before turning on your IR camera, you will have a general idea of the relative "leakiness" of
a dwelling. The greater the airflow required to reach a certain pressure differential the more leaky a living unit is.
The most effective thermal imaging work in an energy audit will occur indoors when a living space is being heated or cooled (winter or summer), not in the spring or fall when there is little discernable difference between inside and outside temperatures.
What savings are possible?
Given rising electricity prices, follow-up actions based on the findings of an energy audit are almost certain to save at least 15 % of the energy a household uses. Figures available on the
DOE "Energy Efficiency and Renewable Energy" website illustrate what savings are available
from even modest energy conserving investments.
Follow-up actions
The remedy for energy-wasting leaks is to seal them. Seal plumbing runs and plumbing vents at
tops and bottoms. Seal utility access holes and recessed lighting fixtures as required. (Warning:
If not done properly, sealing recessed lighting "cans" that are not...
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