My name is Kathy Eastman; I'm the editor of Smart Choices newsletters for your electric cooperative. My family has lived in our central Iowa home for the past 13 years. And for all of those years, we have struggled with making our home more energy-efficient, seemingly with little success until now.
Our task: To make our home more energy efficient. If we can't do that, we will probably move.
Find out about our home and our energy problem. And find out about the numerous steps we have already taken in the past 13 years.
Did these measures help?
Bottom line: It’s hard to know for sure, but we haven’t felt as if the measures have had a substantial impact. While we’re sure our efforts did reduce our energy consumption some, we still feel that our bills are way too high for our lifestyle.
Do we move to another, newer, more energy-efficient home? Give up on improving this home’s energy efficiency? We like our neighborhood and the lovely setting we have and moving is a hassle. On the other hand, our children are nearly grown and moving would be easier with them out of school. What should we do?
Before giving up and moving on, we have decided to take one more step: Having a whole-house systems audit. I set up an appointment with the energy experts at Cenergy to spend a morning at my house, evaluating everything from air infiltration to the functioning of my HVAC system. This may well be one of the best-spent days I’ve ever had.
Let me share what happened and what I learned about my house.
Bob Brice, co-owner of Cenergy, explained that they would look at the house as a whole to see how the systems work together. They don’t just look at insulation or the furnace or the ductwork. They check everything.
Air infiltration first
Bob and his assistant Brandon Cox first set up a blower door. It’s a fan set into a plastic frame that they set up in the open doorway of the house. It sucked air out of the house, and because all the other windows and doors were closed, the fan created negative pressure. The fan then began to pull air in through any cracks and crevices. We could feel air blowing in; it was wild! Bob says, “This procedure simulates a 20 mph wind hitting the building all around. We can actually measure how much air penetrates the building envelope.”
While the blower door was sucking in air, the three of us checked out each room’s leaks and gaps using a thermal scanner to see what we could also feel as air rushed into the house.
Some areas were not surprising, while other leaks were unexpected. Check out what we saw (with photos).
Our HVAC system
The next piece in the puzzle is to examine how well the furnace is functioning. I didn’t expect a problem here, as we know our system is rated at 96%, we keep it well-tuned, and have a high-efficiency filter installed. How wrong I was!
The guys hooked up a series of measuring contraptions to the ducts and to the furnace box. What they found shocked me! The furnace was working at only 49% efficiency! No wonder our heating and cooling bills are so high.
Bob explained that he measured static pressure, like taking a blood pressure reading. If it’s too high, the flow of air is restricted; too low causes problems, also. The problem is the amount of air flow, not the equipment we have.
The bulk of our problem is the ductwork; when we upgraded our furnace, the ductwork wasn’t upgraded to match. Newer furnaces—and especially heat pumps—need much more air flow to work properly, which means the ductwork should be larger to handle the air flow. Our system is choked on both the supply and return runs.
“Adjustments often need to be made in combustion, air flow and ductwork,” Bob says. Tests show that the air conditioning coil buried deep within our HVAC system is clogged; we’ll need to hire someone to clean that component. In addition, we’ll need to rework some of the ductwork both coming in and going out of the furnace. “While that won’t be cheap—someone will have to figure out how to fit the larger components into our limited space—it’s certainly cheaper than investing in a new furnace,” Bob says.
After that work is done, we can consider duct sealing. Bob emphasizes that sealing absolutely cannot be done until after the ductwork is fixed. “If the ductwork is sealed before matching it to the needs of the furnace, it makes the system even more choked up,” he says.
Sealing the ductwork will do more than make our system more efficient. Bob looked at our heat registers and pointed out how dusty they are. Embarrassed, I told him that our home has been dusty since the first day we moved in. We’ve had ductwork cleaned and have installed a high-efficiency filter in an attempt to clean up. We also thought the new windows and doors would help. So far, nothing has worked. I could dust this afternoon and by tomorrow morning, we’d have a coating of dust over everything.
“The dust has nothing to do with how often you clean—or don’t,” he says. “Leaky ductwork running around the perimeter walls of the home can pull dirt in from outside and funnel it throughout the home. It never gets to the filter.” Whew! Our dusty house is not totally due to my poor cleaning skills!
Our next steps
Check out what we have done and what is planned.
Time will tell
I am anxious to see if the combination of these fixes makes a marked change in our utility bills. Time—and a few more utility bills—will provide us with the answer!