Residential Comfort & Energy Efficiency

Written by Eric Gans, Building Analyst & Envelope Professional
I'm a certified energy auditor and insulation contractor in Maryland. I used to fear Cape Cods and avoided insulating them. Now, I welcome the challenge!
 

 

The Cape Cod Life

Michael had lived in his family’s Cape Cod-style home since birth. Over the years, he experienced significant discomfort due to temperature fluctuations and high energy bills.

He sought a permanent solution and turned to Hometrust Remodeling for a comprehensive energy audit.

Home History and Challenges

Michael’s home, built in the 1950s, is a typical Cape Cod style with a conditioned basement and 2367 square feet of total living space. Initially, comfort issues were minimal on the main floor, but as Michael moved to the upper floor, the extreme temperature differences became more noticeable, especially in the summers and winters.

Realizing the Need for a Home Energy Audit

Understanding the importance of a detailed energy audit, Michael sought professional help. He had tried various temporary fixes like weather seals and space heaters but realized a comprehensive solution was needed to address the root causes of his home's inefficiencies.

Conducting a Comprehensive Home Energy Audit

Our team conducted a thorough energy audit using advanced diagnostic tools, including thermal imaging and a blower door test. We inspected key areas such as the attic, knee walls, and crawlspace to identify significant insulation gaps and air leaks.

The audit measured an air leakage rate of 5571 CFM50, indicating substantial energy loss. One way to think about it is air changes per hour.

How many times does the volume of air inside the home exchange with the outside air in one hour? Brand new houses have to be equal to or less than 3 ACH.

Given the volume of living space inside Michael's home (18,936 cubic feet), we calculated the Air Changes Per Hour (ACH) to be approximately 17.65 ACH. This was calculated using the formula:

Here is how it works out for Michael's house:

• CFM50 is the airflow in cubic feet per minute at 50 Pascals (5571 CFM50) x 60 (minutes per hour)
• Volume is the volume of the house in cubic feet (2367 sq. ft. × 8 ft. ceiling height = 18,936 cubic feet)

This high ACH value confirmed significant air infiltration, necessitating extensive remediation.

Identifying Critical Issues

The audit revealed several critical issues: insufficient insulation in the attic and knee walls, significant air leaks around the foundation in the basement, and uninsulated areas in the crawlspace. These factors contributed to the drastic temperature differences between the floors and high energy bills.

Michael’s home showed an annual energy cost of approximately $2553, with significant portions attributed to space heating and electric baseload. 

 

Designing Cost-Effective Solutions

To address these issues, we recommended comprehensive air sealing and the addition of high R-value insulation in the attic, knee walls, and crawlspace. Specifically, we aimed to reduce air leakage to 3500 CFM50 and insulate key areas to R49 at the flat and R38 at the slope. These improvements were expected to save Michael $644 annually in energy costs.

Financial Feasibility and Incentives

The total project cost was initially estimated at $6334. However, with the help of the PEPCO program, which offered substantial rebates and incentives, Michael’s out-of-pocket expense was significantly reduced to $1583.50. This made the project affordable and cost-effective, with a simple payback period of 2.5 years and an annual rate of return of 40.66%.

Executing the Plan

Our team implemented the recommended solutions by sealing all major air leaks and installing new insulation. The work included treating major attic bypasses and insulating accessible knee walls with foam and air barriers.

The project was completed in two visits, ensuring minimal disruption to Michael’s daily life.

Achieving Results

Post-implementation tests showed a significant improvement. The blower door test recorded a 34% reduction in air leakage from 5571 CFM50 to 3671 CFM50. This improvement translated to enhanced energy efficiency and substantial savings on energy bills.

Michael provided feedback after the work was completed:

"They’re a lot better than last year. I bought a Google temp sensor that pairs with my thermostat, and so far, the only difference between upstairs and downstairs is 4-6 degrees, and that’s most probably from heat rising and solar gain. The humidity problem has drastically reduced, and for the most part, I can get away with just cooling off with a fan, even with it being 86 outside. Probably a bit down the line, we’ll look into upgrading the HVAC system and switching out the single-pane windows (there’s some leakiness due to how thin they are). Thank you again for everything! I will be keeping you updated as we head into the consistently hotter days/months." 

Final Thoughts and Future Plans

Michael’s case highlights the transformative impact of a thorough energy audit and proper insulation on home comfort and efficiency.

For homeowners experiencing similar issues, a comprehensive energy audit is a crucial step toward a more comfortable and energy-efficient home. By addressing the root causes of energy loss, significant improvements in comfort and cost savings can be achieved.

"It's these little things hidden behind the drywall or the ceiling that you don't think about. After seeing the report and realizing how much insulation was missing and where the major air leaks were, it all made sense. The audit helped me understand the root problems, and now the house is much more comfortable and energy-efficient." Michael - Lives in Cape Cod House