Watching Those Filters

Thermal Imaging Components: The Blower Door

Thermal imaging is one of the most effective way to identify problematic energy leaks in a home or business. This technique utilizes an infrared camera to detect places where cold air is finding its way into your home. Yet this camera is far from the only component involved. If you would like to learn more about the thermal imaging process, read on. This article will discuss the role played by an equally important component: the blower door.

Blower Door Basics

If you were simply to walk around the inside of your home with an infrared camera you might find it difficult to locate energy leaks. That's because the pressure being generated by your HVAC system makes incoming air difficult to identify visually--even with sophisticated infrared technology. The blower door's purpose is to help even out the pressure differential between the interior and the exterior of your home.

Alternately, you could say that the blower door makes it easier for cold air to get in. That in turn makes it easier to see where the leaks are occurring--and thus to address them through structural repairs and increased insulation.

Blower Door Structure

There are two main parts to a blower door. The first is a door-sized panel made from a flexible yet airtight material. This panel often comes housed inside of a rigid frame that can be extended to fit the precise dimensions of a given doorway. The second part, equally important, is a high-powered fan.

This fan is, by necessity, capable of being fitted into a correspondingly sized opening on the flexible panel. There it acts to blow air from the inside to the outside of your home, thus lowering the pressure differential. Additionally, the blower door assembly will contain a number of pressure gauges. These are used to determine when the ideal pressure differential has been achieved.

Blower Door Prep Work

A blower door system is fairly self-contained and self-sufficient. Yet to ensure the best results, there are a number of things you'll want to do to get your home ready. The first is to close all windows and doors that open onto the outdoors. Interior doors, on the other hand, are best left open; this will help to achieve equal depressurization.

Next you will need to shut down your HVAC system. This may appear counter-intuitive at first, since the whole idea is to capitalize on the temperature difference between outside and inside. Yet if your blower fans are running, they will disturb the movement of air leaks, making their source more difficult to pin down.