When I bought a Victorian two-flat in 2006, I was charmed by its oak trim, tall ceilings, bay windows, and classic Chicago shotgun-style layout. I shrugged at the ancient furnaces and drafty windows—feh! These windows are original, baby!
After two frigid winters, however, I could no longer ignore the fact that I was paying almost $300 a month to keep my charming vintage apartment at a drafty, uneven 63°. And my tenants, though I bought them a brand-new, high-efficiency furnace, still paid over $200 to keep their place only slightly warmer.
I was determined to address the problem, but where to begin? The place had 100-year-old windows, no insulation, leaky ductwork, and a drafty attic. New windows seemed an obvious but outrageously expensive step. I suspected that insulating the attic would help, but how? Should I pour loose fill under the floor? Staple fiberglass batting to the roof? I had visions of struggling with enormous bats of itchy pink fiberglass in a sweltering attic only to find that I’d done it wrong. And what if the furnace broke down in January? Was I really prepared to make the best choice in replacing it? I was reluctant to spend so money and effort without being sure that I was doing the right thing.
I decided to make an appointment with the aforementioned Informed Energy Decisions, a home energy auditor. I spoke with Cappy Kidd, the owner, who promised to investigate the place from top to bottom and provide me with detailed recommendations, listed in order of importance. By the end, he said, I’d have a long-term energy-reduction plan to undertake step-by-step as I could afford to do it. I was psyched.
Based on the square footage of my home and the fact that I have two furnaces (one for me and one for the tenants), they charged me $750. With just one furnace it would have been $600; an audit for a single-family house runs somewhat less, depending on the size.
The audit took place on a hot day in August. Inspectors Cheryl Pomeroy and Aaron Lund showed up at 10:00 a.m. with a carload of equipment. They loaded everything in and sat down with me at the dining room table to find out my concerns and describe their process. After chatting for awhile, they got to work.
Step 1: The Heat-Seeking Camera
The
infrared camera (which looks like a television camera) can detect the
difference between heat and cold; it is used to look for insulation
gaps in walls. This test is actually much more useful in wintertime
when the contrast between outside and inside temperatures is
pronounced; the camera can see the gap in the insulation because that
is where the temperature of the wall is much lower. In summertime, you
can’t see much because the walls are pretty uniformly warm. However,
you can see the heat left by your hand after you touch the wall, which
is kind of cool.
For me this test was a moot point, since I don’t have any insulation except in my kitchen and bedroom, where I insulated the outside walls with fiberglass during a renovation.
Step 2: The Blower-Door Test
Cheryl and I
went around the house and closed all of the doors and windows in both
apartments, including the storms. The idea is to replicate wintertime
conditions, when you seal the house as tightly as possible. In the mean
time, Aaron set about installing a tremendous contraption in the front
door involving a large fan, red canvas, some thin plastic tubing and a
digital meter called a manometer, which measures pressure. The contraption is called a blower-door;
it sucks air out of the house and measures the rate at which the air
leaves. The higher the air flow, the draftier your house.
After we had the place closed up, Aaron turned on the fan (it was loud) and took the reading. Cheryl performed a set of calculations and told me that under average conditions (i.e., not unusually windy), my house exchanges 100% of its air every hour. That means that the furnace has to heat the entire house all over again every 60 minutes. Was that a lot? Ideally, she said, it should take three hours for a complete air exchange. In other words, my house is three times as drafty as it should be.
I wasn’t surprised.
Step 3: The Smoking Gun
It
took a lot of imagination to think that six months from now these
drafts, so welcome in August, would be turning my toes numb. So it
goes. As I walked through the house, I found powerful drafts in some
unexpected places. By the windows, no surprise. From my back door,
which opened to a three-season porch (let's say two-and-half), I felt a
wind that practically knocked me down. I knew the kitchen was drafty, but jeez. I'd had no idea. But strangest
of all was the breeze that emanated from around my dishwasher. After
scratching my head a minute I realized that when installing the
dishwasher, my carpenter had probably not closed up the drywall behind
it, leaving a hole wide open into the plumbing chases and creating a
huge draft from the attic and basement. Who knew?
Cheryl pulled out a smoke wand (available at your neighborhood magic
shop) and held it up to every place likely to reveal a draft. Some of
the worst culprits were the heating vents. Before you think, "duh, of
course there's air coming through the vents!" realize that this is not
the air that's supposed
to be coming through the vents, but the air that leaks through the
rough openings where the ducts are hooked up to the floor or ceiling.
In winter, this would not be the warm air from the furnace, but the
cold air from the attic or basement, getting sucked in through the
gaps.
We cased the entire building this way, leaving a piece of blue masking tape to indicate each of the drafts so that I could go back later to seal them up. Other problem spots: windows (naturally), the bases of walls (along the quarter-round), electrical outlets and the bases of light fixtures. The first- and second-floor apartments yielded similar results. The basement showed a few holes to the outside, large but easily filled, as well as extra vents cut into the ductwork, suggesting that someone had once lived in the basement and diverted some of the heat from the first floor. That explained a lot: my tenants were heating the basement as well as their own apartment!
(Another odd thing in the basement was that the main heating duct was covered with aluminum foil. What the heck??? Aaron was very diplomatic: "Ahm, just so you know, foil is a poor insulator.")
Troublesome as these discoveries were, they were few enough and easily
remedied. The attic, on the other hand, was a bit of a mess. Holes,
gaps everywhere! The balloon frame, shown at right, left an open
channel in the walls from top to bottom, so that any crack in a wall
downstairs would open into the walls and up into the frosty attic. Even
the two walls with fiberglass batting were unsealed, since the open
fibers allow air to travel vertically.
The
attic floor was full of holes, as was the ductwork. And the plumbing
chases were wide open. It was suddenly clear to me that all that air
around the dishwasher was being sucked from a big hole in the attic
floor, as shown below. (This also gave me some insight into how rodents travel through a building.)
Step 4: The Prescription
After leaving bits of blue tape all over the house, Cheryl and Aaron returned to the dining room to write up their findings and recommendations. It took at least an hour, which is to say they were very thorough. They filled out a Window Survey, an Air Sealing Survey, an Energy Condition Summary and then a two-page Action Plan, which listed three major priorities:
1. Air-seal and insulate attic.
2. Insulate outside walls.
3. After house is fully sealed and insulated, replace worst windows as budget permits with double- or triple-pane thermal windows.
Beyond that was a list of smaller projects including tankless water heaters, weather stripping, etc.
Imagine my delight at being told that I did not have to run out and spend $20,000 on new windows! Cheryl was quite emphatic that the windows were far from my biggest problem: my attic was performing like a great big chimney, creating a draft through which all of my warm, expensive, fossil-fuel-burning and carbon-dioxide–producing air was flying into the sky. If I covered my windows with plastic like I do every winter, they'd do a perfectly good job until I could afford to replace them.
When I expressed my gratitude at this news, Aaron nodded and said, "If we save you from buying one window you don't need, you've paid for the audit right there."
We spent quite awhile talking about strategies for insulating the attic, which I will discuss in further posts. Finally, they packed their gear into their little four-door sedan (without an inch to spare) and were off on their way.
I ran back upstairs and pored over the literature they had left me and the reports they had prepared in such loving detail. I couldn't wait to call the insulators.