What happens here?

What happens here?

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Thursday, March 21, 2013

Insulation is like a practical pair of shoes. Not sexy but oh so comforting.

The price of solar electric panels, or photovoltaics (PV), is really low. Depending on the source I've seen price guidelines that range from $1.75 to $3.75 per watt installed. That's actually a huge range and part of the reason is that most installers quote costs AFTER incentives (Rebates, tax credits, local tax allowances, etc.) which vary widely by location. But, PV is still a good deal. So why wouldn't it be the first thing you do?

Well, for one thing I work mostly with conservation measures, so it's less work for me. A better reason might be very simple. Conservation, air sealing and insulation, will make you more comfortable, PV panels won't.

Aha! I saw your head turn. You like to be comfortable, right? I can do it for you and save you money. Those PV panel can save money but they won't make you feel all warm and secure on a cold winters night. Let's have a little chat about the least sexy part of this, air sealing.

Air sealing involves some really dirty work, see least sexy above. You climb into attics, move insulation raising all sorts of dust (you are wearing a really good dust mask aren't you) and seal every large, medium and small hole you can find. The temperature in the attic is probably between very hot and hotter-than-people-are-able-to-survive-at. All the sweating you are doing will make the dust you are raising stick to your skin. The good part is that when you come out of the attic you will feel chilly. Even if it's 95F and humid.

After the attic you can do the crawl space and/or basement which will be cooler, but could be nasty in a different way. All in all this is pretty unglamorous. But if you have eliminated most of the big drafts in your house you will be more comfortable (no cold air blowing over your skin) and saving money. The more holes you fill the more you save.

Insulation comes after air sealing. Almost always. Sometimes insulation is air sealing, but only if it is rigid and not fluffy. Depending on your choice of insulation you will be dealing with materials that are either itchy, dusty, or both. Unless it is rigid, then it will cost a lot more. And you will be back in the attic and crawlspace. YIPPEE!

So how will insulation make you more comfy? It will warm up the surfaces near you. OK, that's not the same as warming up you, but really it's better. Just a bit of physics, that's all. Heat behaves very consistently, it goes to cold. That is, a warm thing will give up heat to a cold thing. Since you're typically warmer than the walls and ceilings, or you should be, you will be giving up heat to them. The warmer they are the less heat they will take from you. That make you more comfortable. Simple right? Just not very sexy.

That's OK. Now that you're nice and comfy you can sit around and plan how you're going to get that PV system installed.

Questions or comments, or if you want to complain that I really dumbed down the physics just use the comment box below.

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