What happens if you seal up the leaks in your house… add a bunch of insulation… and then find out it’s too tight?
For a while now, we’ve been telling you about an attempt to make a 110-year old house in Michigan the oldest net-zero home in America. Net-zero means it uses no more energy than it produces. Lester Graham has the latest installment in our ongoing story.
Matt Grocoff is getting close to his goal. He’s been sealing up his drafty old house, restoring and tightening the windows, insulating everywhere possible. But he’s got to make a change. The house is so tight, he now needs an air exchanger to get some fresh air circulating, otherwise, the air would get too stale – too much CO2 and not enough oxygen.
He kinda knew eventually he’d have to have one, but wasn’t exactly sure what kind or where he’d have to put it. It turns out the attic is going to be the best space because of easy access to return air ducts. Since this project is all about energy efficiency, the air exchanger is a fancy energy-saving unit. We’ll talk about it more in our next report.
But first the attic has to be insulated at the roofline.
I’ve climbed up a stepladder to lift myself into the attic and peek at what’s going on. A guy in a hazmat-like suit and filter mask is spraying insulation foam on the underside of the roof.
If you think of the attic as the triangle shape at the top of the house… you’d usually insulate the bottom of the triangle to keep the rooms below warm. But, because of the new equipment Matt will be installing… the angled sides of the triangle need to be insulated. This is called a ‘hot roof.’
Doug Selby is with Meadowlark Energy. He’s the contractor for this job.
DS: “With a ‘hot roof,’ what we’re able to do is to insulate the actual roofline itself. So, it creates a conditioned space in the attic and what that does for us is seal a lot of the places where a house leaks naturally and it also creates a space where we can run our mechanicals without fear of losing a lot of that energy to the atmosphere.”
We’ll get to why that’s important in our next report on the energy efficient air exchanger that they’re installing.
But for now… let’s just say… it’s kinda cool to see this sticky foam sprayed on the underside of the roof… expand for a bit… and then harden into a sort of styrofoam that’s sealed every nook and cranny. Matt Grocoff says this is easier than it might sound.
MG: “You’re right, we’re spraying it into the rafters rather than laying the stuff onto the floor. And if you look for Greenovation TV on our Facebook page, you’ll be able to see some photographs that we’ve got up there and you’ll be able to see exactly how this stuff is installed and sprayed in and what it looks like when you’re done.”
It’s making a whole new usable space out of an attic that was not usable for much of anything.
Matt can finish it off with drywall, paint it, and then put down a floor. Voila! New space.
MG: “Well, that’s one of the cool things, is that we’re kind of fantasizing now about what we’re going to do with this extra space. And what we think we’d like to do is just have this little cozy space, we’ll put a little pull down ladder up in the attic and have a little yoga space or a little place with some cushions where we can read and stuff like that. And just make it a really cozy, quiet getaway up there in the attic that will be conditioned.”
LG: Matt Grocoff the Greenovation-dot-TV guy, doing yoga in his attic. Alright, thanks, Matt.
“My wife is the real yoga expert.”
We’ll look at the new air exchanger the Grocoffs will install in a small part of that attic space… next Tuesday on the Environment Report. I’m Lester Graham.
If you’re wondering how to make your house more energy efficient…. Matt recommends first getting an energy audit to find out where the leaks are in your house. You can find out how to do that and you can catch up on Matt’s adventures on our website: environment report dot org. I’m Rebecca Williams.