Sustainable Structures, Inc             

Blower Door

Thermal Imaging

Carbon Monoxide Test

Gas Leak Test

HVAC Exam

Would you like to know how your home performs? Call (207) 446 2357 to set up an appointment, or click here to contact us by email.

Below is a description of
a typical audit.

On-site residential energy audits include visual inspection and imaging, defining and measuring the building's thermal and air barriers, combustible gas leak testing, carbon monoxide testing, blower door testing, thermal imaging, HVAC system efficiency overview, exterior drainage, water infilitration and basement issues.  Also focusing on problem areas as requested.

The on-site process takes about 4-6 hours, based on homes less than 3000 square feet. After the on-site portion, a Whole House Report takes a couple of days to produce.

It is not necessary for you to be present for the on-site process, but it is encouraged. Full access will be needed to basements, attics, crawlspaces, and other areas related to energy efficiency.

A blower door is used to measure the rate and costs of the leakage, and provide a benchmark for comparison to other structures of similar size, shape, and orientation.

A special fan is set up in an outside door (typically the front door), safety adjustments are made to combustion appliances, and the home is put in winter-mode (all exterior doors and windows shut, etc.).

The test takes about 20 minutes and depressurizes the home to -50 pascals which is similar to a 25 mph wind at all sides of the home. After the test, the fan is adjusted to a lower level and thermal imaging is used to scan the home for air infiltration.  

Thermal imaging, also called infrared imaging or thermography, is used to find and measure temperature differences of surfaces. In a home energy audit, entire rooms can be quickly scanned for air leaks, missing insulation, moisture problems, and a variety of other issues.

In order to achieve useful thermal images, there should be a temperature differential of at least 5 degrees F between indoors and outside. By using the blower door in conjunction with thermal imaging, many hidden leaks can be found.

A collection of still thermal images with explanation is included in the report.

As part of the energy audit, carbon monoxide levels are checked at several locations in the home. High level readings are noted in the report and could be an indication of backdrafting, improper burner adjustment, cracked heat exchangers, or other issues.  Gas-fired ovens and ranges are also tested for carbon monoxide.

All homes should have at least one carbon monoxide detector (in addition to smoke detectors) near the living and bedroom areas. These detectors should be replaced every few years as the sensors tend to deteriorate.

All accessible gas lines are checked for leakage using similar equipment to what is used by the gas company. Many leaks can not be found by smell alone.

Ratings for your furnace and air conditioning equipment are referenced, general conditions are noted, duct systems are examined, filters checked, and findings are included in the report.