Blower Door Update
Dear Comfort Advisor,
Due to the rather dismal real estate market, I have decided to stay in my home instead of trying to sell it. My winter utility bills on my older home have been so high I have been using budget billing. Where to start?
Dear Dismal Dale,
At least you are not alone in your predicament, either in the real estate woes or the budget billing. With the real estate market, just give it some time, with the high energy usage, get moving now. The best way to get started is to get an assessment of how your home performs. There are several “must knows” to chart a direction and use your money and time wisely.
Knowing how much your home leaks air is very important in discovering where your energy dollars go. The tool that makes this possible is called a “blower door test”. A metal frame is expanded in place of the front door and this frame is covered with an airtight fabric. A very powerful calibrated blower is set in the frame and the home is depressurized by exhausting air out of the home. The amount of negative pressure is like having a 25mph wind against the entire exterior of the home. This pressure allows us to see and feel where the air leaks are. It is pretty amazing to feel the force of the drafts coming through all the various cracks and holes in the shell of the home. Once you know where they are you can get moving with caulk, spray foam, weather-stripping, and lots of elbow grease. In addition to finding air leaks, the blower door also measures the rate of infiltration in ACH (air changes per hour). This number is plugged into a heat loss calculation to determine what that leakage is costing you in energy dollars.
A heat loss calculation is used to determine how much energy is needed to keep your home warm. It requires accurately measuring the home including square footage of floors, walls, windows, and ceilings. All these factors, depending on how well insulated they are, have a HTM (heat transfer multiplier). These numbers are all added up to come up with a BTU requirement for your home. I use a specific computer program to crunch these numbers and to create graphs to depict where your energy dollars are going and to create alternative scenarios to demonstrate how much energy can be saved by sealing all those air leaks, adding a little insulation, changing out those single pane windows, or switching to a more efficient heating system.
The last bit of knowledge is knowing how efficient your heating source is. Whatever your mechanical system, most manufactures suggest annual maintenance. Checking efficiency at that time is fairly easy. With gas equipment, an exhaust gas analyzer will quickly and accurately determine combustion efficiency. Checking heat output vs. current draw will determine efficiency of most heat pump systems. Electric heat is by design 100% efficient, but cleanliness, proper airflow, and leaks in the duct systems can really impede actual efficiency.
With a blower door test to determine building leakage, a heat loss calculation to determine correct equipment sizing, and an efficiency check on your current equipment, in a few short hours you will know how do best spend your energy dollars. As a “performance based contractor” AirWorks provides these services for those who are ready to find solutions to increasing energy costs. Since you are on budget billing a careful review of your past utility bills will make clear how much extra energy you go through during the heating season. Conservation by reducing energy waste is, and has always been the best solution to addressing these problems. Please give me a call with questions and comments.