Today there are an unprecedented amount of financial incentives available for building energy efficiently. These incentives come from State and Federal government, utilities, manufacturers and others. Together they add up to thousands of dollars per house. Most of this money can only be accessed if a systems analysis is performed. John Bushnell of Bushnell Energy Consulting says, “Typically our service pays for itself by ensuring that you receive all the energy efficient incentives that are currently available.”
Professional energy auditors like John Bushnell use blower door tests to help determine a home’s airtightness. The Energy Saver 101 infographic explains the importance of a blower door test during a home energy audit. – https://energy.gov/articles/energy-saver-101-infographic-home-energy-audits
A home energy audit is often the first step in making your home more efficient. An audit can help you assess how much energy your home uses and evaluate what measures you can take to improve efficiency. But remember, audits alone don’t save energy. A home energy audit pinpoints where your house is losing energy and what you can do to save money.
These are some reasons for establishing the proper building tightness:
- Reducing energy consumption due to air leakage
- Avoiding moisture condensation problems
- Avoiding uncomfortable drafts caused by cold air leaking in from the outdoors
- Determining how much mechanical ventilation might be needed to provide acceptable indoor air quality.
A blower door test locates air leaks by using a special fan to depressurize a house.
How They Work
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. The auditors may use a smoke pencil to detect air leaks. These tests determine the air infiltration rate of a building.
Blower doors consist of a frame and flexible panel that fit in a doorway, a variable-speed fan, a pressure gauge to measure the pressure differences inside and outside the home, and an airflow manometer and hoses for measuring airflow.
Diagnostic Tools
There are two types of blower doors: calibrated and uncalibrated. It is important that auditors use a calibrated door. This type of blower door has several gauges that measure the amount of air pulled out of the house by the fan. Uncalibrated blower doors can only locate leaks in homes. They provide no method for determining the overall tightness of a building. The calibrated blower door’s data allow the auditor to quantify the amount of air leakage and the effectiveness of any air-sealing job.
Preparing for a Blower Door Test
Take the following steps to prepare your home for a blower door test:
- If you heat with wood, be sure all fires are completely out – not even coals – before the auditor arrives. Remove any ashes from open fireplaces.
- Plan to do a walk-through of your home with the auditor. Be prepared to point out areas that you know are drafty or difficult to condition comfortably.
- Expect the auditor to request access to all areas of your home including closets, built-in cabinets, attics, crawl spaces, and any unused rooms.
- The auditor will need to close all exterior doors and windows, open all interior doors, and close any fireplace dampers, doors, and woodstove air inlets.
- Expect the auditor to set controls on all atmospheric fossil fuel appliances to ensure that they do not fire during the test. The auditor 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.
While there are many financial incentives available, they won’t last forever. Rust never sleeps and utility costs never go down. It certainly makes sense to test your home or your business building for airtightness and consider what investments might save you in costs for the future. Here in the Greater Puget Sound Region home energy audits are performed by bushnellenergyconsulting.com. The goal of home energy audits is to save you money, while still providing a cozy place to live.
This Blower Door Test Information is provided by https://energy.gov/energysaver/blower-door-tests
