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July 1, 2019
The one thing Kim Nixon didn't want to be in her new Farmingdale home was cold.
"If it's not 70, I'm freezing," she said on a recent morning. "I want to heat this place warm enough all winter and for it to be affordable for me on a single income."
Unfortunately, her 1960s pre-fab ranch was cold because of the various air leaks found in the basement, attic and windows. This led to a series of other problems, most notably there was significant mold growth in the attic.
"We came in the midst of an active renovation," said Tom Linder, an Energy Auditor for The Breathable Home. "Mold had developed on the roof deck from air gaps in the ceiling, which allowed warm, moist air into the attic where it condensed on the roof."
This moisture was not only generated from the home's previous occupants' daily living habits – primarily bathing and cooking, but also from water leaking in through cracks in the basement.
There was a whole-home approach to fixing both the cold (air leaks) and moisture problem. Kim worked at replacing the windows. "The wind was whistling through them," she said. We tackled insulating both the attic and the basement, in addition to controlling air transfer through the installation of a bath fan.
In the basement, we sealed all penetrations and cracks with hydraulic cement and installed 2 inches of spray foam to the foundation walls, insulating and air sealing the rim joists (a signifcant source of air exchange.) These measures effectively prevented moistrue from coming into the home from the outside as well as making it air tight.
The first step in the attic was to treat the existing mildew before correcting the conditions that allowed the mildew to form in the first place. With the mildew treated, we air sealed a leaky flue, an attic hatch which fit poorly and was unsealed, and various other gaps and penetrations. Finally, we blew in cellulose to insulate to R-49.
"Now, with more thermal resistance to prevent conductive heat loss and air sealing measures to keep the conditioned air in the home, we have effectively prevented heat and moisture from connecting with the roof deck," said Tom. "This will prevent both ice damming and the further development of mildew."
Now that the home was sealed, we wanted to make sure Kim's home wasn't too tight. For this home, "too tight" would be a blower door number of 1,080 cubic feet of air flow per minute (CFM) at a pressure difference of 50 pascals. Her post-work blower door test was 1,000 CFM. A smidge too tight, but easily fixed.
Anticipating this scenario, we had installed a Panasonic Whisper Series bath fan which can remove 110 CFM, delivering it safely to the outside. Not only is it ideal to run the fan while showering to control the moisture generated then, the fan can also be programmed to automatically run for a specified amount of time every hour. For a healthy level of air exchange during the winter months when the home is sealed at its tightest, we calculated that the fan should run for 1.7 minutes every hour.
With the home sealed, the moisture in check and the air at healthy levels, Kim could now keep her home efficiently warm. Having both a heat pump as her primary heat source and a heat pump hot water heater, she said this "gentle electric" use kept her electric bill at $130 for month of February this year. And she used no oil during that time.
An added benefit came with all the insulation work, one Kim was not expecting.
"All of a sudden, it got crazy quiet inside my house," she said. "I used to hear everything from the street noise to my neighbors talking. The day they did the insulation, there was a hush. It's as if it cocooned the whole house. It made it feel more solid."
Beth N, Chelsea
Steve is a convert! He glowingly talked about how much warmer the house is in the morning, how it retains heat overnite....So, from skeptic to believer.....We are VERY happy with the work. No problems or complaints and I appreciate the fact that you are checking in. Will keep track of wood/oil use next winter.