11-08-11, 05:47 PM | #1 |
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More insulation or more BTU's?
Moving this discussion over here so I don't clutter up the KWH thread
My house is 2 stories,about 1800SF, 1/2 on a finished basement and 1/2 on slab. 2x4 construction with R13 batts and 1" of some sort of foam board from the 70's under newer siding. Attic has 8" blown in fiberglass and I added R19 to that (almost R40 total). Ceiilng above finished basement is insulated from the first floor via R13 batts . Newer double pane windows throughout. Front door and garage entry door are steel insulated. Rear slider to 3-season room is a nice Pella. All heat is currently electric re$istance baseboard, no ducts, no access to NG . I also have two small children so controlling hvac in bedrooms is important to us. Basement doesn't need any additional heating but I will probably pull the panelling and put up a couple inches of foam on the walls before re-rocking; also I'll likely add 1" to the floor while I'm at it. No plans on pulling the siding because it's in really good shape and don't want to add foam to living space, that would make our small rooms even smaller. So that's about it, I'm open to suggestions on either insulation or heating systems. Right now I'm leaning toward 8.2 HSPF Multi-splits. I had a 4x9kbtu grunaire in my last house and we were really happy with it. But for this house we would want 5 indoor units (3 for bedrooms, 2 downstairs), with 2 outdoor units. Thanks! |
11-08-11, 07:51 PM | #2 | |
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If you want a better argument for not insulating from the inside, try the argument that tearing the walls out will totally disrupt your family's life and make your wife and you miserable while you are working on it. Then there is the expense, since the geometry of inside walls is more complex and you'll have to do so much twiddly fitting to make it really good, especially the finish work around windows and doors to account for the extra depth. Again, I think you're shooting too low. The HSPF for the Fujitsu Halcyon 12RLS is 12, why not go for the gold? But you might want to try a blower door test before you try anything else. Some cities subsidize such a thing, so it's free or cheap. -AC_Hacker
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11-08-11, 08:21 PM | #3 |
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"electric re$istance baseboard"! Ouch! Or, maybe not.
What is the total kwh rate you pay? How many kw hours (per month) are you using for heat on average, during the heating season? And do you live in a area with a mild climate? Where you only need heat during Dec & Jan?
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11-08-11, 10:56 PM | #4 |
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I agree with AC Hacker and would just like to reinforce the blower door test, or a DIY leak test. Your insulation doesn't seem too bad, but if your house isn't sealed up good that insulation doesn't do much good at all.
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11-09-11, 01:16 AM | #5 |
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Seal first, then insulate. I read somewhere that every $1 spent on insulation is worth a few bucks saved on heating/cooling. And insulation on the outside is more effective than on the inside - maybe you can wait 5-6 years for that to be done?
Of course, in the meantime you can install a mini-split or two and use the baseboard on colder days, or only in rooms without the mini-split. Just make sure that you don't end up with a surplus of minis after you finish sealing and insulating.
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11-09-11, 08:11 AM | #6 |
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I've added insulation to small rooms before and found it to be worth while, I felt that using foil faced foam gave the best results, also if you pull off the old dry wall you have a chance to seal up any cracks and gaps and that is a big part of installing foam as well is sealing up cracks at the same time.
Your attic insulation, the fiberglass will allow more air flow then cellulose does, so pulling the fiberglass in to the center and air sealing where the ceiling meets the outside walls, then adding blown in cellulose will help more then just going over top of the fiber glass, fiber glass doesn't slow drafts as well as cellulose and expanding foam will stop drafts. |
11-09-11, 05:44 PM | #7 |
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Thanks for the input so far guys.
AC Hacker- I agree that it would be very little reduction in space, however if you add in the mess, cost and time I would probably rather pull the siding and wrap the house with foam instead. Much less disruption to the family and would probably do a much better job of sealing with no reduced space. That will probably wait a couple yrs down the road though. Blower test is on the list for sure. |
11-09-11, 05:48 PM | #8 | |
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11-09-11, 05:53 PM | #9 | |
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11-09-11, 06:00 PM | #10 | |
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