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The final test of our home energy project

Marc Lefkowitz  |  04/13/12 @ 4:00pm  |  Posted in Home efficiency

Having our house insulated and sealed from heat loss-with an eye fixed on the rebate from GoodCents-has been a long, but not particularly hard process. A few months after the initial energy audit, we had the final inspection today. We were relieved when Sean, the friendly GoodCents inspector who came to our house, confirmed that we should expect the work to pay for itself in a few years.

Once again Sean hooked up the giant fan to the front door to test how well the insulation is slowing energy loss. He walked us around the house pointing at walls with the handheld infrared camera. After we hired a firm to insulate and air seal our attic and basement, we found our home to be a lot less drafty and noticeably more comfortable. We paid Cleveland firm Kilroy Home Insulation $2,100 to blow cellulose which is made from recycled newsprint treated with Boric acid into the attic, and to seal up with expanding spray foam major gaps in the house's frame.

We planned on spending another $2,500 to have cellulose blown into all walls, but paused after this phase of the house in order to gauge our impact.

It turns out we did slow what Sean called the "stack effect". The wall cavity acts like a chimney, pulling air up from the basement and out through the attic. Before the work, we tested at 1.05 roomfuls of air changed per hour. In other words, our whole house was being refreshed but also losing all of the heat that quickly. Sean's blower door test today showed us at .75-the ideal is .35, but Sean doesn't think our old house will ever achieve that number (to be exact, we went from 5,735 cubic feet per minute at 50 pascals of pressure to 4,000; we passed the test, but the standard is 1,904 cfm50).

"It's as if you closed a fifteen inch gap in your house," he said while scanning the insulation in the walls of the attic with the infrared camera (the studs show blue which means insulation is in there). He inspected their work and confirmed they did a good job.

Sean also asked if we had insulation put in the roof? We did not. We had fiberglass bats and air baffles rolled in six years ago when we replaced our roof. He gave me that, ok, that's too bad look. I asked him what we could have done better? We were told there was no more room to add insulation up there.

Sean agreed that removing the fiberglass and then blowing in cellulose from the inside would be labor intensive. And would the cost pay for itself was a question he didn't have the answer to.

He did inform me that codes have changed that now allow closed cell foam (which has much more insulating value than fiberglass) sprayed in to roofs. Roofing companies agree that this 'hot roof' scenario is fine, he said, they won't void your shingle warranty. He added that Owens-Corning paid for a study that shows 40% of home heat is lost through the roof.

This conversation left me with the impression that roof replacements are a huge opportunity for reducing the heating energy used in an existing home. I get the impression that not enough consumers are educated about this, and wonder if roofing contractors don't want to be the bearers of the 'expensive news'. If so, than who will? What will improve the odds that homeowners will capitalize on a roof replacement with a really important (and, I assume, shorter payback) insulation job?

Maybe to make us feel better, he noted the insulation work we did in the attic significantly slowed air movement, and that the walls of the house are most likely our next low (in terms of impact, not expense) hanging fruit. When I shared my concern about the chemicals and pollutants in standard closed cell foam insulation, he did say that cellulose blown in to the roof would be much more effective than fiberglass because it prevents air movement.

It all raises the point that energy retrofits are only as good as the technology and codes at your present moment. Technology seems to be outpacing energy codes in Ohio which are still at the 2006 (not the 2009 level). Not that it would have helped us at the time of our roof replacement. We actually had a decent roofer back in 2006 – he took the time to explain the benefits despite the slightly higher cost of insulation. The good we thought we were doing though is now overshadowed by today's progress.

Knowing that from the get-go didn't stop us from moving ahead with GoodCents. The basics of insulation and air sealing have not changed, and since we had zero in each category, it made sense for us to do something. Yes, we were enticed by the GoodCents rebate because it will defray some of the costs, but the real reasons we did this was to improve the comfort and quality of living in our home (sure, lowering our energy costs is a factor).

In the end, having the information from the real time analysis has made a big difference, too. We're in less of a hurry to insulate the walls knowing that we already improved our energy loss by nearly 1/3-the value add of the $50 audit cannot be underestimated (and it's probably why, Sean said, there are a lot of Clevelanders taking advantage of the GoodCents program while it lasts-it's set to expire by the end of 2012.)

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