Blower door testing helps us understand where structures leak and is the first step toward building tighter, more energy-efficient homes.
What is a blower door test?
The purpose of Blower Door Testing is to measure the air tightness of a home and check for air leakage. A blower door is a powerful fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings.
Image courtesy of energy.gov/.
These are some reasons for establishing the proper building tightness:
Reducing energy consumption from excess air leakage
Avoiding moisture condensation problems
Avoiding uncomfortable drafts caused by cold or warm air leaking in from outside
Controlling outdoor contaminants, pests, and odors from entering your home.
Determining proper sizing and airflow requirements of heating and cooling equipment.
Determining whether mechanical ventilation is needed to provide acceptable fresh air and maintain indoor air quality in your home.
Determine the air infiltration rate
While the blower test is being conducted, our insulation specialist may use an infrared camera to look at the walls, ceilings, and floors. Moreover, this test finds specific locations where insulation is missing and air is leaking.
Preparing for a blower door test
Our experienced insulation specialist performs the blower door test. This includes a walk-through of your home, setting up the blower door, and conducting the test. The following steps will help prepare your home for a blower door test:
Plan to do a walk-through of your home with the specialist. Be prepared to point out areas that you know are drafty or difficult to condition comfortably.
Expect the specialist to request access to all areas of your home including closets, built-in cabinets, attics, crawl spaces, and any unused rooms.
The specialist will need to close all exterior doors and windows, open all interior doors, and close any fireplace dampers, doors, and woodstove air inlets.
If you heat with wood, be sure all fires are completely out – not even coals – before the specialist arrives. Remove any ashes from open fireplaces.
Expect the specialist to set controls on all atmospheric fossil fuel appliances (e.g., furnace, water heater, fireplaces, and stoves) to ensure that they do not fire during the test. The specialist should return them to the original position after the test.
Expect the test to take up to an hour or more, depending on the complexity of your home.
The Green Cocoon offers custom, cost-effective solutions to make your home or office building more comfortable. Additionally, this saves you money on your energy bills. Our troubleshooting and diagnostic skills separate us from the pack! For more information, contact us
The Green Cocoon has many tools in its arsenal to help you stay warm and save you money. One of those tools is a thermal imaging camera. Where and why do we use it? We use it when we come to your home to evaluate your space. We use the camera to show you where cold air is coming in. Also, the camera comes in handy when we need to discover if there is insulation inside a wall or ceiling. We don’t have to guess. The camera tells us!
What is a thermal imaging camera?
Thermal imaging cameras are devices that translate thermal energy (heat) into visible light. This is done in order to analyze a particular object or scene. Furthermore, the image it produces is known as a thermogram. The analysis of a thermogram is done through a process called thermography. Thermal imaging cameras are sophisticated devices that process the captured image and display it on a screen. The image can be used for immediate diagnosis. Or, they can be processed through specialized software for further evaluation, accuracy, and report output. Consequently, thermal imaging cameras take measuring temperature to the next level. Instead of getting a number for the temperature, you get a picture showing differences in temperature.[i]
Here you can see thermal bridging through ceiling joists and how a lack of air sealing can really spread the cold air
Here we see a completely uninsulated wall bay
This photo illustrates how much cold comes through an outlet switch cover that isn’t properly air sealed and insulated
Thermal imaging camera applications and uses
The first commercial thermal imaging camera sold in 1965 for high voltage power line inspections.[ii] Since then, thermal imaging cameras have been used in many fields. Firefighters use them to see through smoke, find people, and localize hotspots of fires. Additionally, physiological activities can also be monitored with thermographic imaging. Fever in human beings and other warm-blooded animals is just one of many.
Building construction technicians can see heat leaks to improve the efficiencies of cooling or heating. Additionally, thermal imaging cameras are a common tool used by home inspectors.
Camera used in our evaluation
When our salesperson comes to evaluate the space you would like to insulate, they will be using a Thermal Imaging Camera. Having a tool that instantly shows a client where and how much insulation is needed, is invaluable.
Contact us to schedule an appointment.
[i] Grainger. Thermal Imaging Cameras Explained. Retrieved from grainger.com.
[ii] Wikipedia. Thermographic Camera. Retrieved from Wikipedia.org.
When you are ready to insulate your living space, you may be contemplating what R-value you will need. And why not? It is the most widely accepted measure of insulation and often aligns with a minimum code requirement. But assuming that your wall assembly will realize the R-value of your insulation ignores a crucial variable in building science—thermal bridging. Understanding and managing thermal bridging will make your living space more comfortable. And, it will save you money!
What is thermal bridging?
Thermal bridging is when a particularly conductive (or poorly insulating) material allows heat flow across a thermal barrier. Physics dictates that hot wants to go to cold and a thermal bridge is a perfect invitation. The best analogy is to think studs within an insulated wall. The insulation on either side of a stud will do its job of limiting heat flow. But, the wooden stud, which has a much lower R-value, will not. These bridges can become expressways of heat loss.
How does this work in a home?
To understand and manage thermal bridging, let’s continue with the stud example. The typical R-value of a 2×4 wooden stud is 4.4, while the insulation on either side is much higher—typically greater than R13. The result of this bridge is heat being transferred and a significant loss in the wall’s effective R-value. In a wood stud wall with R20 insulation, thermal bridging can reduce the effective R-value to as low as R15. One of the worst thermal bridges is a metal stud. This can reduce effective R-value by as much as 80 percent. Along with studs, other typical building materials that create thermal bridges are metal fasteners, plates, headers, and windows. Typically, you can observe these all around a house—roofs, walls, fenestrations, for example.
The impacts of thermal bridging
If you are losing heat through thermal bridges, the efficacy of your climate control system decreases and uses more energy. Furthermore, these bridges can create cold spots within your walls where condensation can easily form. This moisture can produce a whole host of issues to the wall cavity—mold and mildew or rot, to name a few. Excessive moisture also challenges the structural integrity of your wall.
How do we prevent or limit thermal bridging?
Luckily advancements in building science and common sense can really help limit thermal bridging. Realistically, most homes will have some thermal bridging happening, but there are tools at our disposal to help prevent it.
Exterior insulation – According to Havelockwool.com, a better term would be “out-sulation.” This means that by wrapping the exterior of your home in insulation you can prevent (or dramatically reduce) the common thermal bridging via wall studs. Cork is a great option. You can spray foam the exterior, add rigid board or Rockwool as well.
Advanced house framing or Optimum Value Engineering – The goal of this building technique is to reduce lumber used in framing, which reduces thermal bridging. There are a lot of strategies incorporated, including spacing wall studs up to 24 inches on center, eliminating headers in non- load-bearing walls, designing on two-foot modules to make the best use of common sheet sizes, and to reduce waste.
Insulated studs – The company T Stud produces an R19 stud that is a thermally broken, insulated wall stud assembly. They also have the BareNaked Tstud™, which is an uninsulated, thermally broken wall stud that you can insulate with the insulation of your choice. These studs can not only reduce thermal bridging, but they are incredibly strong.
“Alternative” Wall Assemblies – Structural Insulated Panels (SIPs) are a common alternative to stick-built construction and can help limit thermal bridging. These panels have an insulated foam core between two rigid board sheathing materials, which when installed properly, can provide a continuous air and vapor barrier. There are issues, however, including the use of foam. Bamcore makes a bamboo wall system that is an environmentally friendly, extremely high-performance option.
Understanding and managing thermal bridging is easy
In conclusion, understanding and managing thermal bridging is a must because thermal bridging happens in every home. And, if you are constructing a new building, you can take care of that very easily. If you have older construction or renovation, you can use the best insulation possible in between the base to mitigate the amount of thermal bridging happening.
Contact us, and we’d be happy to answer all of your questions.
This article is based on an article from Havelockwool.com.
While the blower test is being conducted, our insulation specialist may use an infrared camera to look at the walls, ceilings, and floors. Moreover, this test finds specific locations where insulation is missing and air is leaking.
How does this work in a home?
