House power audit finds air leaks, power inefficiencies

My house is over a century old. I bought it for its character and charm – the hardwood floors, the brick fireplace, the artisanal layout. But as every homeowner knows, character and charm can also be euphemisms for creaking and cracking. Cracks that allow air to escape and send my heating and cooling bills through the roof.

In early May, I decided to tackle the leaks head-on – planning a visit to GreenIowa AmeriCorps. They conduct free energy audits for residents across the state and have offices in Cedar Rapids, Cedar Falls, Dubuque, Des Moines, Decorah, and Fairfield.

The seven GreenIowa volunteers currently stationed at Cedar Rapids work onsite at Matthew 25, where they conduct energy, environmental activities and education. The major funding, coordinated by the University of Northern Iowa Center for Energy and Environmental Education, is provided by the Iowa Volunteer Commission, the Corporation for National and Community Service, and UNI.

Energy audits are exactly what they sound like – they aim to find out how energy is lost in a house. After testing for energy leaks, the GreenIowa volunteers make recommendations and do the weathering work to fix minor issues.

“Our main goal behind this is energy saving and education. This is a reduction in your energy consumption and a reduction in your bill, ”said exam coordinator Sebastian Negron.

The volunteers who arrived checked to see that my water heater was working and checked for leaks on gas water heaters, oven and gas pipes, and offered to replace any old, inefficient lightbulbs they found. The heart of the audit, however, was the blower door test.

This essentially affected the AmeriCorps volunteers who attached a large fan to my front door and sealed the rest of the door. The fan pulled air out of the house and sucked in fresh air from outside through every gap. A computer tested the amount of air moving through the house while the volunteers walked around the house looking for leaks.


In one case, a poorly insulated cellar wall was evident in my basement – the flowing air made cobwebs flutter and flutter. The air flowing through my house blew open the hatches to a crawling room in the attic and was felt on my hand next to window frames.

Some ventilation is good – nobody wants to breathe in their own carbon dioxide emissions. This can actually be a problem in newer homes – Negron said they are often designed and built so tightly and energy efficiently that not enough fresh air gets in. Sometimes energy auditors actually recommend adding extra ventilation to newer homes.

But for those of us in more historic homes, the opposite is the problem. The blower door test determines the air exchange rate per hour in the house, which should ideally be between 0.35 and 0.40.

Mine was at .64 so there was definitely work to be done.

GreenIowa only does low impact weathering – they haven’t re-insulated my home or replaced my windows, things I know I might do in the future.

But there were much smaller, simpler things that made a huge difference. They attach my crawler flaps to keep them closed and slow the flow of air through them. An invisible seal around a kitchen window frame and thin foam tape around the inside of two door frames helped fill in some obvious gaps. Under my sink, they used spray foam and some support rod insulation to fill a gap around the pipes. Negron explained that plumbers often make the holes for pipes larger than necessary for easier installation. Finally, they sealed the biggest problem areas in my basement with spray foam.

Both labor and materials for GreenIowa energy audits and weathering measures are free for low-income residents, the elderly, veterans, and the disabled. For others, the weathering work is free, and GreenIowa only charges the nominal cost of supplies. I paid $ 20 for the sealant, foam tape, and latches they used.

As I watched them at work, I was skeptical that these basic fixes would make a huge difference. But when they ran a second blower door test, I was pleasantly surprised with the results – an 18.75 percent reduction in air leaking from my home that they estimate will save $ 154 annually. My new ACH number was .52. Still not .40, but significantly better than where it started.

This is good for me and mother earth.

“We can essentially only help your house. We’re helping your energy bills and helping you help the planet, ”said Ellen Ziesenhene, Public Relations Coordinator at GreenIowa.

Energy audits

Find out more or schedule a home energy audit with GreenIowa AmeriCorps:


Contact: (319) 362-2214, greeniowaCR @,

Alliant Energy and MidAmerican Energy also offer energy audits:

Contact: Alliant Energy: (866) 255-4268,; MidAmerican: (800) 545-0762,

Comments are closed.