This is a Technology Report Guest Post
Tim Snyder is a journalist that frequently writes about sustainable building topics and green living.
Tim is an in-house writer for Dr. Energy Saver, a network of home energy audit contractors.
Advancing the science of saving energy with apps & hi-tech equipment
More than one journalist has compared the house to the human body when attempting to explain the many factors that influence home energy performance. The string of metaphors in
this discussion includes a circulatory system (ductwork), an HVAC “heart” that pumps conditioned air t throughout the house, and a multi-layered skin (the “building envelope”) that provides protection from the elements as well as insulation.
In this “house-as-human” analogy, a home energy audit is the equivalent of a comprehensive health checkup, involving an extensive inspection to diagnose various energy-wasting conditions and prescribe appropriate treatments. A homeowner who follows this customized prescription for energy savings can expect several important benefits: reduced use of electricity and other energy sources like natural gas or fuel oil, improved “green” value because of lower carbon emissions, lower utility bills and improved indoor air quality.
Not surprisingly, the science of saving energy (technically referred to as “building science”) has fostered a small revolution in hi-tech equipment and software. Where yesterday’s energy auditors were taught to sketch house elevations and floor plans on a paper pad and figure heating and cooling loads with a calculator, today’s auditors are entering values on a tablet touch screen to produce faster, more accurate energy audits that include specific recommendations and projected energy savings. Even the most basic DIY energy assessment programs include factors such as lighting (# of CFLs or LEDs compared to incandescent lights), appliances, water heater efficiency, insulation levels, window specifications and climate zone.
While some companies (like kWhOURS www.kwhours.com and Optimiser www.optimiserenergy.com ) focus on providing energy auditing software for laptops and tablets, others offer hi-tech equipment. Using a specially designed infrared camera, you can produce thermographic images showing temperature variations that indicate air leaks and/or missing insulation. During a blower door test (a standard diagnostic procedure during an energy audit), a powerful, computer-controlled fan is installed in an exterior doorway to depressurize the house. With the house set to “winter” mode while the fan operates (windows and exterior doors shut), it’s possible to measure air leakage and even pinpoint leak locations using special smoke-generating tools.
The technology being used in energy audits is quite remarkable. Just as medical specialists can assess internal organs with tiny cameras that enter the body through small incisions, an energy analyst can peer into wall cavities using a borescope. Utilizing fiber-optic technology, this diagnostic tool can pass still or video imagery through a flexible tube that the technician inserts into a building cavity through a small hole.