PreservationNation

Written by Barry Goodinson

Editor’s Note: This is the fourth installment in a week-long series exploring the author’s recent home energy audit. Please stay tuned as more posts – and lessons learned – are shared

Time for the ultimate test!

A few hours (and several very important and/or dramatic lessons) into my home energy audit, and it was finally time for the real deal: The blower test.

We closed all the exterior doors and windows in the house and Ken, our technician, stretched red sheeting over the front door. A large round hole in the sheeting accommodated an electric fan. A second piece of equipment, with a tangle of various air-pressure-detecting plastic tubes, was mounted to the door and the tubes were threaded out the door and across the front hall. Because my academic training is in philosophy, public policy, and garden design, I could only nod as Ken explained air pressure differentials, equations, and other such things. What I did understand was that the fan was creating a major air current that would draw all of the air in the house out through the front door, and that the air that was leaking into the house through windows, doors, and other invisible cracks would move similarly. This exaggerated movement would allow us to feel drafts where there was air infiltration, and the crazy tubes and monitors would give an overall rating of our home’s general leakiness.

According to Ken, the standard (i.e. acceptable) rate of air exchange (leaking) for a building is .35/hour. That means that 35% of a home’s inside air is replaced with air leaking in from the outside every hour. A rate higher than that means your house is not sealed tight enough. A rate lower than that means your house is too tight and that the air could be unhealthily stagnant. Having lived in old houses most of my life, I knew our charming home would be “drafty.” What I learned was that the scientific measure of charming/drafty at our house was 1.4/hour – which meant that we were trading all of our inside air with the outdoors in the span of less than an hour. An efficient-yet-healthy house takes three hours. Our place got the job done in less than a quarter of that time.

Not. Good. News.

In addition to the hold-your-hands-against-a-window-and-feel-the-draft method, Ken also produced an infrared camera that detected temperature differences and displayed them as colors on the camera’s screen. Blues and greens indicated cooler temperatures, while yellows and reds indicated warm and hot. We walked around and Ken pointed out several places where the house was leaking like a sieve. Most predictably, the camera showed that our windows and doors were the biggest draft-producing culprits.

Except for three replacements on the third floor, our house still has its original windows. These 110-year-old windows open and close with varying degrees of success, having suffered generations of painting and decades of pulley abuse. More importantly, according to Ken’s infrared camera, they all performed quite poorly in creating an effective barrier between inside and outside air. In the temperature-as-color world of an infrared camera, a well-sealed window doesn’t look that much different from the wall that surrounds it. The temperature is uniform from window to wall, perhaps appearing more orange than the surrounding yellow wall. If a well-sealed window is photographed with sunlight shining directly on it, it will appear as a clearly-defined square or rectangle of red against its yellow surrounding wall, with the camera capturing the heat on the surface of the glass. When viewed through Ken’s infrared camera, our windows looked like glorious western sunsets, their red, irregularly-shaped centers blossoming and bleeding into the orange and red swirls that were our walls.

Despite what my home energy auditor thinks, my historic windows matter.

“There’s the problem,” Ken intoned. “These windows. You’ve got a couple of choices here. You can either replace them or try to seal them. Me? I’d replace them, but that’ll cost ya.”

Now, if you’ve followed the ongoing window conversation at the National Trust for Historic Preservation, you know that the consensus here falls decidedly on the side of restoring old windows and installing good quality storm windows. That’s my inclination, too. To me, a building’s windows are one of its most important features – its soul or eyes – and the installation of a new shiny (often-times plastic) soul is seldom successful from an aesthetic standpoint. Additionally, the wholesale consigning of building waste to the landfill, only to create the need for plastic- and petroleum-based replacements, is hard to swallow. But, so too is the notion that we were burning four times the amount of energy we should to heat and cool our house.

Several months ago, I contacted a local preservation organization in search of someone to restore our windows. I was given several leads, but none panned out. The best I could do was to find a craftsman who told me that he could show me how to restore the windows myself. Now, I’m fairly handy (although my experience with the air conditioning filter had shaken my confidence some), but I didn’t think my schedule, skills, ego, or domestic tranquility could withstand such an undertaking. So, given a choice between restoring my home’s windows myself and replacing them with new ones, I made the obvious choice: I did nothing.

And this is often the dilemma faced by owners of older and historic homes – we want to do the right thing for our old homes, but our schedules, skills, or local markets do not always make that very easy. However, with Ken’s blower test showing us that our house is “charming” and an environmental menace, inaction is no longer an excusable or ethical option.

Barry Goodinson is the director of historic sites development at the National Trust for Historic Preservation. Please stay tuned throughout the week as he takes us behind the scenes of his recent home energy audit.

Want to learn more about energy audits and making your home more efficient? Check out the National Trust’s Weatherization Guide for Older and Historic Buildings.

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This entry was posted on Thursday, August 5th, 2010 at 9:23 am and is filed under Green Preservation, Homeowners, South, Weatherization. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.