Tuesday, January 18, 2011

"Drive-By Energy Audits"

This is what my job has enabled me to do, in more ways than just looking at how much snow is left on rooftops as a determinant of how poorly insulated the house is.

I recall an advanced solar workshop I took around this time last year, in which the instructor told us we were "solar teenagers."  We know just enough to be dangerous to ourselves and others, without the refinement of years of experience.

I guess I'm like a green building teenager: bursting with new knowledge, that my opportunity to practice it to refinement has not yet caught up with.  I know enough to know, for example, that the fact that my house has no housewrap is kind of a very bad idea, but am not in possession of enough wisdom to know if it's really worth taking all the siding off to put it up. Ostensibly doable and actually very low-cost if DIY--yet really, is it worth jumping into a huge and consequential project I've never done before?

(As an aside: how else do you go from not knowing how to do things to knowing how to do them, whether you're a solar teenager, a building teenager, or a hands-on-skill teenager of any other kind?   Like the whole "if you don't know how to fix a car; you're not stupid, you just haven't learned how to do it yet" quote that I love so much.  Sometimes you really do have to take the opportunity to do things, on your own terms and in your own way, to get the experience to not be a "teenager" anymore.  This path is fraught with the peril of mistakes, and it would be best if one could learn from the mistakes others have already made first, but sometimes it seems the choice is between potentially making a mistake or sitting on the couch and thinking "gee, I wish I knew how to accomplish something!")

Anyway.  From the linked post:

This blog isn't at all meant to suggest that we should skip a "real" energy audit as we think about how to improve the energy performance of our houses. A thorough energy audit by a weatherization contractor will include a blower-door test and, often, thermographic analysis (in which a special infrared camera is used to identify areas of excessive heat loss). But the drive-by energy audit after a snowstorm is a great way to get a quick sense of the need for a real energy audit.

Maybe the experience of an energy teenager can point something out here.  Both of those tools, the blower door test and a thermal camera, are things the physicist in me salivates over--they provide awesome information about the performance of the house, and they might even be best done after you make improvements so you can see how well the improvements worked.

But they are expensive.  Not in the thousands, as energy retrofits might be, but if you're going to spend thousands it is a hard sell to spend a few extra hundred on something that only tells you how effective your thousands might be.  When we do audits, we don't do these tests, and we don't do them after retroftis either, because our audits and retrofits would cost a lot more than most folks are willing to pay if we did.  And the energy-not-so-teenager knowledge we can provide is enough to bring people savings, if not the abosolute most savings that could be wrung out of the house considering available technology, then likely savings on the same order of magnitude in cases with extremely "low hanging fruit," which probably any house older than 20 years old that hasn't had any energy efficiency attention is going to have plenty of.

I can't tell you how much I'd love to "nerd out" to the level of thermal cameras and blower door tests on every house I see, but alas nerding out is pretty expensive.  That was one of my biggest disappointments on entering the business world from the academic one:  cost matters.

So the wisdom of the "drive-by audit" is that in many cases this stuff isn't quantum astrophysics.  If there's not much snow on the top of your roof, it's because all the heat you're paying to pour into your house is going there.

Here are some more low-hanging fruit drive-bys, courtesy this green building teenager/former quantum astrophysicist (research technician for one, anyway):

1) If your heating and cooling ducts are not in conditioned space (the are in an attic or a crawlspace or garage), you are wasting a lot of energy.  There is also nothing you can do to completely fix this, seeing as you can't move them now, but you can still get some benefit from sealing and insulating the ducts.  Because the amount of energy this setup wastes is very large--like a fuel line in a car that leaks out 20% of the gasoline before it gets to your engine--this is a Do This First For Instant Payback fix.  

2) If there are gaping holes in your walls, floors, and ceilings themselves, fix them before you put any money anywhere else. It doesn't take a thermal camera to show you they matter a lot, but if you had a thermal camera, you'd notice the holes would be a completely different color (indicating a vastly different temperature, and usually the opposite extreme from what you'd like your house to be) than anywhere else.

3.) If you are keeping an 10+ year old extra fridge in your un-conditioned garage for the cooling of your alcoholic beverage supply...consider whether it's really worth $600 a year to you to keep your supply of beer cold.

4.) If you live east of the Mississippi River and are shopping for a home to buy or even rent, and you like the idea of the house maintaining structural integrity past the first year or so after it's built (forget energy, structural integrity comes first) don't let anybody tell you that gutters and/or overhangs are not necessary.

No comments:

Post a Comment