Case Study: Home energy efficiency makeover
By Gina Mathias and Alexandra Young
Winter is coming, and with it chilly drafts and high heating bills. Most home owners can likely pinpoint a few of the biggest energy wasters in their homes, but many of the places in your home that drive up your bills remain harder to diagnose. That’s where a professional comprehensive home energy audit can help.
Takoma Park resident Keith Kozloff recently had a comprehensive energy audit. He also helped his neighborhood team earn points for the Neighborhood Energy Challenge by completing upgrades to his home to save energy.
Energy audit: $0 after rebate and subsidy. Keith initially paid $100 for the energy audit, which normally costs $400. Because he chose a participating Pepco contractor, the cost is subsidized through EmPOWER Maryland. Through City of Takoma Park Energy Efficiency Rebate Program, Keith received a $100 rebate for the energy audit.
Energy audit recommended work: $1,512 after rebates. The total cost for the insulation and air leakage reduction package was $4,262.30. Keith qualified for the 50 percent, up to $2,000 Pepco insulation and air sealing rebate, the Takoma Park 25 percent up to $500 energy efficiency rebate, and the $250 Montgomery County energy efficiency tax incentive.
Lifetime energy savings: $3,005. The recommended work included wholehome air leakage reduction attic insulation and crawl space insulation.
What was the biggest surprise the energy audit revealed for Keith? He had no idea that a large amount of air was getting through his 2nd floor crawl space (or “kneewall”). The energy audit revealed that the space was only half insulated, making it ambiguous if it was an interior or exterior space. After speaking with the auditor and learning the options for how to better treat the space, Keith decided to make the crawl space an exterior space. He moved the insulation and fiberglass batts to an inner wall and then covered the wall with a reflective air barrier. Keith also insulated the half door leading to the space. The contractor sprayed dense pack insulation in the floor through holes drilled in the floor.
Other improvements included sealing air leaks in the attic floor, basement, and other areas of the home with caulk and spray foam. After the contractors achieved a targeted rate of air leakage reduction, measured by a blower door, insulation was added to attic floor to bring the total thermal value of attic insulation to R49. Keith hopes an upstairs bedroom that was too warm in the summer and a downstairs office that is too drafty in the winter will be much more comfortable.
The importance of working with a professional energy auditor:
Many do-it-yourselfers can install insulation, caulk and spray foam. Beyond finding energy savings, however, energy auditors perform tests to ensure that projects are completed in compliance with safety standards. A blower door test measures how drafty your home is, ensuring it is within safe levels. Most homes in Takoma Park are well over the building airflow standard necessary for safe indoor air quality. However, over-tightening your home can cause once properly venting gas appliances to back-draft, spilling dangerous flue gasses into your home.
Combustion safety tests measure the pressure of flue gasses being vented from the appliance to outside your home, including carbon monoxide. While the blower door is running, there is also a better chance to find hidden drafts and areas of missing insulation, especially when used with an infrared camera.
The improvements didn’t stop with insulation and air leakage reduction. Committed to helping reduce greenhouse emissions, helping his neighborhood win the Neighborhood Energy Challenge, and the City win the Georgetown University Energy Prize, Keith has made more changes that will make home as energy efficient as possible and earn him a Takoma Park Dark Green Home certification.
Solar PV rooftop installation: $7,209. Total system cost before federal and state tax credits $11,433.
Solar lifetime electricity savings: $28,094. System size is 2.94 kW. This will generate approximately 3,323 kilowatt hours of electricity per year, representing about 70 percent of Keith’s total electricity needs annually. This estimate was made before many of Keith’s energy efficiency improvements were completed; the total dollars saved on electricity may be lower; however the panels may get closer to generating 100 percent of Keith’s electricity needs.
Other energy efficiency improvements Keith has made:
- Super efficiency boiler and hot water system
- Energy star appliances (refrigerator, washer and dryer, dishwasher)
- Programmable thermostats
- Motion sensors on outdoor CFL security lights
- LED and CFL light bulbs throughout home
- Blinds and shades on windows to minimize/maximize solar heat gain in summer/winter
- Ceiling fans to make rooms more comfortable at a higher temperature in summer
- Faucet aerators
- Power strips on electronic device centers
- Cleaning refrigerator coils every six months to improve function
- Blocked off fireplace to prevent drafts
Would Keith recommend using an energy auditor and making audit-recommended upgrades to his neighbors? “Sure, I would recommend this to my neighbors,” he says. “There are three motivations: one is to save money, another is to increase comfort, and the final one is to reduce greenhouse gas emissions.” We couldn’t agree more.
This article appeared in the October 2015 edition of the Takoma Park Newsletter. The Takoma Park Newsletter is available for download here.