There have been several articles recently about thermal images that will be taken of some Arlington/Lexington homes.

Neither Arlington HEET or Sustainable Arlington is affiliated with the program, we don’t get any money from it, and we won’t be able to see any individual images (unless you’d like to share an image of your home with us) but we are supporting it as a great way to show people just how leaky their home is.

What a thermal image of a home looks like.

As frequently as we do audits, and as much as we try to explain heat loss, it is often a difficult concept for people to understand. With good reason – even with a blower door running and a smoke-stick showing just how much air is leaking, it can be hard for the mind to translate that into “I’m losing a lot of money from these leaks and/or lack of insulation.”

There is something about that visual image – the exterior of a home which, in the dead of winter, is bright red from escaping heat, that really helps people understand the value of insulation/air sealing.

Sagewell, the company taking the images, has been driving the streets of Arlington and Lexington late at night, in a fuel efficient vehicle, taking thermal images of homes. They’re now in the process of analyzing the images to highlight the estimated value of weatherizing and/or insulating the homes.

The images will be online in the next few weeks for homeowners, and only the owners, to view. Sagewell has instituted certain privacy restrictions to ensure this. Arlington HEET will not have access to the images, though we’re happy to talk to you about your images if you have additional questions.

With the cold weather (finally) abating, the chances that more images can be taken is slim. There needs to be a temperature differential between the inside of the home and exterior air for the images to be valuable.

However, owners who want to request that their homes be included in the study can send an email to priority@sagewell.com. Sagewell says they cannot guarantee that a particular home will be included in the study. Alternatively, owners can “opt-out” of the study by sending an email to optout@sagewell.com or by calling 1-888-586-1726. The image will then be permanently deleted from their systems.

A note on privacy concerns:
Most of us are probably familiar with thermal or infra-red imaging from grade B military or sci-fi thriller movies. We see thermal images of people, or creatures, moving around in the night. Some people might legitimately be concerned about whether these thermal images might show people inside their home through walls or behind windows.

The simple answer is no, the images cannot do that.

The thermal camera takes an energy reading of the first surface it sees, whether that is a row of bushes, a deck railing, a wall or a pane of glass. It cannot “see” through walls, windows or anything else.

If you happen to have your face pressed up against a window at the precise moment the thermal imaging vehicle is driving past (typically between midnight and 6 am) then the thermal image would “see” and register the temperature of your face, but not your neck or anything else behind the glass.