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SUper insulation is the key to the future of heating

Post in 'The Green Room' started by Seasoned Oak, Jan 6, 2012.

  1. bpirger

    bpirger Minister of Fire

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    I agree that cost is the big motivator, and a part of that, a big part, is the upfront cost for good spray foam work! Has the price of this come down much in the past decade? It may have, but it stills seems to be 5 times the cost of what a DIYer can install fiberglass for. I agree, fiberglass won't compare to what foam can do, either in R value or more importantly in stopping air flow DEAD.

    As a DIYer, I know I just bought all the fiberglass to install in my addition, R38 in the ceilings, R19 in the walls, for less than $1K. 32x32, cathedral ceilings. I spent a few hundred more to put the 0.5" polyiso sheets on the bottom of the ceiling rafters too, hoping to get a better air seal and a bit more insulations under the actual wood of the rafters.

    In any event, the spray foam people I talked to where talking in the > 5K range. Now, I have to deal with all the crappy fiberglass, I hate it. DIY foam kits seam to be coming along, but they are small, and still very pricey.....

    Has the foam been coming down? What's the primary cost with this? Is it just enough high end market that some will pay, enough to support the high end, high margin business? Will future competition bring this down tremendously?

    I'd love foam.....but I can't seem to spring for that extra $4K plus of cash....which is enough to buy all the 5/8 sheetrock, screws, and likely T&G pine to cover it all up!

    And I agree, it would pay itself back, but then again, my wood is free....

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  2. Flatbedford

    Flatbedford Minister of Fire

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    My father is an architect and has been doing mostly residential work for the last 35 years. He has always kept up with the improvements in this stuff and is even LEED cerified ( http://www.usgbc.org/DisplayPage.aspx?CMSPageID=1988 ). he says that the key is to avoid fiberglass as all it really does is filter the heated air that moves out of a building. I hope to some day build my own super insulated home. I am really interested in the stuff. I just wish I had the cash to get started.
  3. jebatty

    jebatty Minister of Fire

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    It must do a little better than that! No disagreement that better materials are available.
  4. Flatbedford

    Flatbedford Minister of Fire

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    I think his point is that it may insulate well, but does little or no air sealing. I was reading that some, at least in new construction, recommend sealing the exterior walls with a couple inches of closed cell foam and then filling the rest of the wall cavity with fiberglass. It would be kinda tricky to do after the wall are closed up. You get the sealing of the foam but also get the cost advantage of the fiberglass.
  5. bpirger

    bpirger Minister of Fire

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    I have seen that technique used quite a bit....a couple inches of foam, then fiberglass. That makes me think that the actual chemicals of the spray foam are a big part of the cost, becuase it sure wouldn't take much time just to fill the cavity with foam once everything is all ready for it! Seems somewhat silly not to....so it has to be a cost driver.

    Yet I don't understand why it would cost much on the scale of spraying a house.

    If you do fiberglass right I think it does much better than when you don't! You really have to take time to try and avoid gaps for air flow. In my place I used a plastic sheeting as a vapor barrier as well. But, without a doubt, I get leakage around outlet boxes and whatnot somewhat. I believe there are things you can buy to help with this....no doubt required code in Canada...but spray foam would certainly just answer the whole thing!
  6. Seasoned Oak

    Seasoned Oak Minister of Fire

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    I have to agree, FBF, iv been rehabbing old houses for about 25 years .I would not give 2c for fiberglass. Only effective when perfectly installed (which is rare) It also shrinks over time and any gap on the sides makes it just an air filter.
    My system is blown in celllulose. If more R value is needed 1" or more of foam board exterior, you can even put 1" or so under the drywall interior. Just the blown in alone does a much superior job than the fiberglass.IMHO.
  7. semipro

    semipro Minister of Fire

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    Its widely called "flash and batt" and getting more common. Fiberglass is not that bad... if the installation is perfect. The problem is that its almost impossible to get it anywhere near perfect even when real effort is put into it.

    During upgrades to our house I've pulled many a fiberglass batt from our house that was obviously acting as an air filter.
  8. Flatbedford

    Flatbedford Minister of Fire

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    About 20 years ago my father put a sizable addition on the 100 or so year old (at the time) former carriage house while I was away at college. Only one room was not redone, my bedroom. When I was home for winter break I gutted my bedroom. He had me fill the odd size stud bays with fiberglass. Then we put a layer of poly iso insulation sheeting walls and ceiling. Taped all the seams and them added sheetrock. I put all new slides on the old wood windows and filled the sash boxes with insulation too. Being a kid, I the work was kinda sloppy, but the room sure was warmer! The thermostat was out in the hallway and I would melt all night in that room when the heat came on. I'd like to go through my house room by room and do the same thing sometime. I'll have to figure out what it would cost me. I'm sure we would all be much more comfortable year round with that kind of sealing and insulation. I could put up with my rooms being a couple inches smaller for some more comfort and using less fuel.
  9. Frozen Canuck

    Frozen Canuck Minister of Fire

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    Yep called flash & batt in the trade. AFA the cost of foam it comes down to really big petro chemical co's getting max margin. What I do know from my 3 BIL's that work in the refinery here is that the base chemicals for spray foam are just about given away by the refineries, essentially these chemicals are waste/leftover in the process of turning oil into diesel & gasoline & they have very few customers for them hence the low sale price. It's not your local installer making a killing, he is likely just getting by in today's economy, it a company that already has billions.
  10. macmaine

    macmaine New Member

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  11. DickRussell

    DickRussell Member

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    I do agree with most of what has been said on this thread about superinsulation and its future. Even for those (mainly the women?) who may give priority to visible things like granite countertops over the invisible things, buried behind the walls, there is the appeal of a very, very comfortable house in a cold climate. I shudder to think of what some of those McMansions in a zone 6 climate must be like on a windy winter day.

    Getting to superinsulation level in a new house isn't all that difficult, but it has to be well thought out at every stage of design and carried out well during construction. Most builders don't know how to get it right, but many are willing to work with the homeowner who has done his homework and learned what has to be done. It does help to be on site as much as possible during construction and to be on good terms with the crew.

    Superinsulation involves insulation levels much higher than what code requires. As one builder puts it in his tagline, "Code is the minimum to pass. You build to code. Congratulations! Your grade is a D-." It also means air sealing well, to make for a very tight house. It's no surprise that the new air tightness standard for the Energy Star program calls for no more than 3 ACH (Air Changes per Hour) at a blower door depressurization to the standard 50 pascals. Actually, it's fairly easy to get significantly tighter than that. The heat it takes to warm up a given amount of cold air leaking in to replace warm air being pushed out is easy to calculate, and the result can be a surprisingly large fraction of a house's total heating bill.

    Some builders still argue that you can't make a house too tight, that it "has to breathe." Well, the occupants have to breathe. The house has to avoid problems of excessive moisture getting into the exterior walls. Making a house tighter helps in that regard, but the inside air should not be allowed to get too humid. One of the first things learned from the first superinsulated houses is that the tightness that is part of the superinsulation design also leads to very high humidity inside, even in the dead of winter, unless fresh air is introduced in controlled fashion. As mentioned, this commonly is done in cold climates through the use of heat recovery ventilators, which are basically air to air heat exchangers.

    The problem with trying to make a house "not too tight" is that there is no way to build it in a way such that adequate ventilation occurs all the time. All you know is that leakage is at its worst in bitter cold and windy weather, and then may be much too leaky for comfort and energy efficiency or still may be inadequate for human health and comfort. In mild and windless weather the leakage will be practically nothing. Worst, there isn't any control over ventilation rate in such a house, short of opening windows, which most folks won't do in winter. So it's not surprising that along with code changes requiring much tighter new construction, confirmed by blower door test, there also are requirements at least in some states for mechanical ventilation to provide ASHRAE section 62.2 minimum fresh air flow. I think Minnesota is one such state.

    The cost of going to superinsulation level in new construction is not all that much. The number I see often is around 5% more. After all, it's only the outer shell that is changed. To be sure, sprayed foam is the most costly insulation, for a given amount of R value, although it does give a typically very tight outer shell. There are less expensive ways to get a tight house, though, and there are other websites out there that cover all such ways in considerable detail.

    In our case, a 2010-2011 build (our retirement home in NH, climate zone 6), the shell is a double stud wall with a 12" insulation cavity filled with dense packed cellulose. That's an R40 wall. Loose cellulose in the attic, 18" deep, gives R60 there. The parts of the lower level walls that are concrete foundation are water proofed (not just "dampproofed") and have a 2" layer of rigid foam both inside and outside, from footing to sill. The above grade part of the exterior foam is protected with surface bonding cement troweled on. Inside the foam is protected by drywall, as required by code as thermal and ignition barrier. Below the slab is a double layer of 2" rigid foam and poly vapor barrier. So concrete walls and slab have R20 insulation on them. The windows are triple-pane, argon filled, low-E coated casements for the most part. Yes, those were expensive, a big part of the extra cost to go superinsulated. I think they are worth it. There is a noticeable difference at the inside of a triple pane window compared to a regular double pane window. The inside glass temperature is notably warmer.

    The final blower door test, with range hood and woodstove ducting all connected, came in at about 0.8 ACH50, or about 0.04 ACH "natural" worst case air leakage. The energy start examiner said it was the second lowest air leakage he had measured, and number one was for a much smaller house.

    One of the nice things about such a house is that selection of heating system almost doesn't matter, from an energy use point of view. The design load is so small that the system is going to be small, for whatever equipment is selected. In our case, since we were having a new well drilled anyway for water supply, we went with ground source heat pump (aka "geothermal"). The unit is a two-stage, two-ton model, the smallest that Climatemaster makes in its Tranquility 27 line. So far the unit has not gone to second stage operation and keeps the whole house comfortable without running full time.

    We do have a small woodstove in the lower level, a Quadrafire Millenium 2100, with the outside air kit connected to a duct to the outside. This winter, our first in the house, we haven't used it too much, but I like to have a wood fire now and then. That little stove, with the glass door, looks so warming with the fire burning so hot and cleanly inside. We actually used that last winter to heat the whole house to mid-50s, running part time (mid afternoon to perhaps midnight), a temperature the crew found quite comfortable while they finished up the inside work. Quadrafire says that stove is good for heating 1,000 sqft.; this house is nearly four times that. The warmed air distributed nice and evenly throughout the house by itself. The up and down temperatures stayed within one degree of each other.
  12. RORY12553

    RORY12553 Minister of Fire

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    Bought my house in September 2011. It was built in 2001. I use a wood stove that is the bottom floor. I am convinced that insulation is the key to everything. The house does cool down if I don't have the stove going but never gets below 62 even when it is 30 outside. I have my baseboard which is fueled by oil at 55 and haven't used any oil yet this winter for heat. I know it has been mild so far and hope it stays this way!
  13. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Did you use regular sized windows? And what was the brand? Some new houses iv seen look like the windows are too small for the house. Im on the fence right now about installing a 60"double french glass door as opposed to a 36 steel insulated kitchen door as im sure the french door will be a cold spot.
  14. DickRussell

    DickRussell Member

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    I went with Thermotech Fiberglass, out of Ottowa, Canada. The frames are all fiberglass, so I won't have long-term issues with moisture in the frames. With the exception of a few fixed windows, and one awning window, all are casements. Typical size is 30x55, some with a 17" fixed transom window over them. Facing the view is a 71x55 picture window with transom window over it. There are two units consisting of three windows mulled together, with an operable window in the middle and fixed glass to either side, and there are four other units consisting of two operable windows mulled together. I think the total window count is 27, IIRC. There is no shortage of window area in the house, without putting them in unnecessarily. My approach was to use fixed glass where reasonable. Not every window in a house needs to be operable. Also, casement and awning windows are far tighter than double hung or sliders. To make a double hung as tight you'd need to have a crank handle on the thing.

    I think you are right about the 60" door being a cold spot. All our exterior doors are 36", and the glass is just double. Three of those have glass perhaps 3/4 of the height, for view purposes. One side door I kept to just the upper half being glass. During some periods of construction last winter, when there was high humidity in the house from plaster and paint work, the triple pane windows would form condensation just around the edges, where the glass unit frames are more conductive, but otherwise the glass remained dry. The doors, on the other hand, had condensation all over the glass. I spent a lot of time in the house wiping up condensation, to limit damage to the wood veneer on the inside (a costly option).
  15. Adios Pantalones

    Adios Pantalones Minister of Fire

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    We do need to breathe. New stuff out gases lots of chemicals you should avoid- formaldehyde is a good example.

    Houses may need to breathe as well. Mold can be deadly, and it can destroy relatively new construction.

    I know a guy that uses a greenhouse on one side and an embankment on the other- heats his smallish off-the-grid house in Deerfield, NH on about a cord and a half a year. Smart construction and a decent compromise I think, but -40 is a rare if ever occurrence there.
  16. ihookem

    ihookem Minister of Fire

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    If ya don't go foam in the walls a good option is blown in cellulose. I built 2 exact houses on the same lot. One with blown in 2x6 walls, the other with 4" closed cell foam. The foam seems to be the better insulation. The cellulose was darn good though. I went all around the outlets and never found a leaker even @ 40 mph wind @ -20 degrees f. The cellulose was 1,500 less than foam. Foam between the basement joists though. That really helped a lot. I am about 11 btu per cu. ft. @ 0 degrees or so with 9' walls s best I can tell.
  17. Vanskills

    Vanskills New Member

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    House heating is a tiny fraction of oil usage

    Literally EVERYTHING from computers, pencils, couches, tvs, etc uses oil. Without oil we would be living in tents hunting buffalo fir food and clothes.

    Just not realistic, can we use " less" oil? Sure.... But we still need oil for atleast the next couple hundred years unless you want to go back to cave man lifestyle which I'm assuming most people font want to.
  18. begreen

    begreen Mooderator Staff Member

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    If one looks at energy (not just oil, gas is a bigger consumption) used for residential heating and cooling, it's a very large number. About half of the energy uses in a household is for heating and cooling. Add commercial space heating and it's a huge number. As a nation, we waste over half of that. There is a lot of value to insulation. Reducing waste is probably our largest energy resource right now.

    "In 2005, about 6.9 quadrillion BTU of direct-use energy was used to heat homes in the U.S.; another 4.1 quadrillion BTU were used to heat commercial buildings."

    as compared to:
    "In 2005, the nation used 21,653 trillion BTU of direct-use energy to turn raw materials into finished products."

    http://www.window.state.tx.us/specialrpt/energy/uses/heat.php

    Even looking just at oil used for heating, the consumption huge. It follows right after transportation.

    "Heating oil accounts for about 25% of the yield of a barrel of crude oil, the second largest "cut" after gasoline (petrol)."

    http://en.wikipedia.org/wiki/Heating_oil
  19. woodgeek

    woodgeek Minister of Fire

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    Um, I think the 25% cut is all distillates, both diesel and heating oil. Globally, most of that gets burnt in Diesel engines, and only a smallish fraction for home heating (at this point).

    On the materials front, there is some good news....biomass. While I think there are real limits to the ability of biomass to replace transportation fuels, it is clear that there is plenty of biomass for making plastics and other chemical feedstocks, and at a price not much different from what we pay now. So, in a world without oil, we will still have modern materials, we just have to work out the transportation issue.
  20. begreen

    begreen Mooderator Staff Member

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    Well I'd like to get this correct. Can you provide a supporting link please? With the focus on the US, not global use.
  21. woodgeek

    woodgeek Minister of Fire

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    Sure, check out the data at the US Energy Information Administration...the EIA:

    http://www.eia.gov/totalenergy/data/annual/index.cfm#petroleum

    and scroll down to line entitled: 5.15 Fuel Oil and Kerosene Sales, 1984–2009
    and check out the graph.

    For 2009, it shows 'on-highway diesel' at ~2.2 million barrel per day and 'residential fuel oil' at 0.268 million
    out of a total of 3.44 million barrels of distillate.

    IOW, residential fuel oil is ~7.8% of US distillate, or ~0.078*25% = ~2% of total crude usage.

    Of course, I agree that we can and should reduce residential energy use dramatically. And let's start with fuel oil.
  22. begreen

    begreen Mooderator Staff Member

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    Thanks, that is the info I was looking for. You are correct about oil, though that is only a part of the heating picture. Notable is the 50% drop in consumption from 1975 to the present while natural gas is on the rise and electrical consumption for heating is up 450%.

    Because the topic is the value of insulation my focus is more on total residential energy use, of which heating (including wood) can be 50%. The graph on this page is what I had in mind. It puts into perspective the impact of residential energy consumption at about 25% of total energy flow:

    http://www.eia.gov/totalenergy/data/annual/perspectives.cfm

    Also notable on this page is the growth of renewable energy of which wood now accounts for 25%.

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  23. Gasifier

    Gasifier Minister of Fire

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  24. Smarl

    Smarl New Member

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    I am putting a 400 square foot addition on my house (house is 1600 square feet - 2 stories at 800). I would like to know how to best construct and insulate it

    I just finshed rehabbing my house. I had 2" of closed cell foam installed on first floor walls, 4-5" on second floor mansard walls and approx 5" of open cell in attic. Windows:Casement, thermopane, low-e

    Addition will be on backside of fireplace (north side) with wood insert (LOPI answer with blower). Furnace is at other end of house (which I dont want to run much as I just bought an insert) and it will be expensive or difficult to have heat vented to addition. I was thinking I could super insulate and install (but ideally not use) baseboard electric heat.

    Current plan:

    -2 x 6 walls inside 6" lannin stone
    -2 x 8 ceiling joists
    -flat rubber roof
    -foam in walls and ceiling
    -full basement


    Detailed questions:

    -Should I build wall with 2 rows of 2x4's to eliminate thermal bridging?
    -Should I fill wall and ceilings completely with foam?
    -Should I used closed cell foam?
    -Should I install triple thermopane low e windows?
    -I think I will install foam board insuallation around foundation (2") and under concrete floor(4")

    My thought is yes to all but I need some validation that I am not going overboard and to convince my wife.

    Incidentally, after reading this thread I am glad I can at least put more open cell foam in attic if I need to. Next year I will have the addition built and no temporary doors so I can seal up nice and tight. I will then assess need to add in attic. Great thread. I will download book at monolithic.com. Thanks
  25. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Smarl
    Sounds like you are on the right path. THere are several ways you could reduce thermal bridging IMO. You could cover both sides of the 2x4s with foam as well as some form of blown in between. double stud walls is a bit overkill, i think there are better more cost effective ways. Have you looked into using SIPs (structural insulated panes)for the walls or ICFs(insulated concrete forms).

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