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Re: [SB-r-us] Exasperation!!

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  • Nancy or David Gray
    We really need to express this as some kind of complex rate of glazing (single vs double) versus total surface area versus latitude and climate.  David Neeley
    Message 1 of 17 , Jan 1, 2009
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      We really need to express this as some kind of complex rate of glazing (single vs double) versus total surface area versus latitude and climate.  David Neeley may be able to address this and there are many other engineers who I hope weigh in.  Personally, I like the idea of double hung, but they should be some ideal size determined as mathematically as possible.  Best, David Gray

      --- On Wed, 12/31/08, Caralee <cgwoods@...> wrote:
      From: Caralee <cgwoods@...>
      Subject: Re: [SB-r-us] Exasperation!!
      To: SB-r-us@yahoogroups.com
      Date: Wednesday, December 31, 2008, 1:25 PM











      I may be off base here depending on what is needed for the porch, but we are planning a south-facing greenhouse on our home, and will be using double-hung windows which will allow us to open both tops and bottoms of the windows for ventilation when needed. Just a thought about another way to create air flow to regulate temperature.

      Caralee

      Kanab, UT

      ----- Original Message -----

      From: David Neeley

      To: SB-r-us@yahoogroups .com

      Sent: Wednesday, December 31, 2008 12:08 AM

      Subject: Re: [SB-r-us] Exasperation! !



      Donna,



      A solar porch can easily be built with removable glass panels--often

      with screens to replace them in warm weather--making it a very

      comfortable space all year round.



      David

      .





      [Non-text portions of this message have been removed]


























      [Non-text portions of this message have been removed]
    • Ross Elliott
      CMHC (Canada Mortgage & Housing Corp.) has a good book called Tap the Sun , which comes with a CD you can use to optimize glazing types, areas & roof
      Message 2 of 17 , Jan 1, 2009
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        CMHC (Canada Mortgage & Housing Corp.) has a good book called "Tap the Sun",
        which comes with a CD you can use to optimize glazing types, areas & roof
        overhangs, I highly recommend it!



        Ross Elliott - LEED-AP, RASDT

        Technical Manager



        homesol final logo smaller

        RR 1, 981 Conc. 11

        McDonalds Corners, ON K0G 1M0

        (613) 278-0467

        www.homesol.ca <http://www.homesol.ca/>











        [Non-text portions of this message have been removed]
      • orleansdonna
        Ross, you previously recommended that book to me in other correspondence. Thank-you. I reserved it at the library and just picked it up on Monday. Looks
        Message 3 of 17 , Jan 1, 2009
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          Ross, you previously recommended that book to me in other
          correspondence. Thank-you. I reserved it at the library and just
          picked it up on Monday. Looks informative. I'm feeling better about
          my choices and probably worry too much.

          Thanks everyone for the feedback.
          Shari, Darcy and Alan, I'd love to compare notes.
          Darcy, no off-grid. Perhaps solar hot-water. Tertiary septic but
          that's it for "alternative".

          Donna

          --- In SB-r-us@yahoogroups.com, "Ross Elliott" <hbs@...> wrote:
          >
          > CMHC (Canada Mortgage & Housing Corp.) has a good book called "Tap
          the Sun",
          > which comes with a CD you can use to optimize glazing types, areas
          & roof
          > overhangs, I highly recommend it!
          >
          >
          >
          > Ross Elliott - LEED-AP, RASDT
          >
          > Technical Manager
          >
          >
          >
          > homesol final logo smaller
          >
          > RR 1, 981 Conc. 11
          >
          > McDonalds Corners, ON K0G 1M0
          >
          > (613) 278-0467
          >
          > www.homesol.ca <http://www.homesol.ca/>
          >
          >
          >
          >
          >
          >
          >
          >
          >
          >
          >
          > [Non-text portions of this message have been removed]
          >
        • LarenCorie
          Posted by: Caralee cgwoods@hughes.net ... Hello Caralee Double hung windows are pretty much in the terrible range, as south facing windows, for Solar
          Message 4 of 17 , Jan 2, 2009
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            Posted by: "Caralee" cgwoods@...

            > we are planning a south-facing greenhouse on our home,
            > and will be using double-hung windows which will allow
            > us to open both tops and bottoms of the windows for
            > ventilation when needed.

            Hello Caralee

            Double hung windows are pretty much in the "terrible"
            range, as south facing windows, for Solar heating. There
            are three very serious problems, with their general design.
            First, and least, their glass size is considerable less than
            with other types, of windows, especially fixed glass.
            Second, the glass is set back into the jambs, sashes,
            and screen frames, where much of it is shaded for much
            of the day. (since it is shaded glass, not wall, it has much
            heat loss, and in cold or cloudy climates, can significantly
            reduce the effective Solar heating). Third, because the
            screens are mounted on the outside of the glass, they
            block about 20% of the light before it even gets to the
            glass (even more at great angles). This means that you
            have to remove and store the screens, for every heating
            season, or lose what can be the critically significant amount
            of Solar gain that may exceed the winter heat loss through
            the glass. I strongly recommend not using double hung
            window, in any climate where heating is a bigger issue
            than cooling, especially on the south wall, . And, I do
            recommend them for the deep south, where their large
            shading effect is desirable.

            In Utah, you get a lot of sunshine, but the critical
            times, are those overcast days, not the sunny ones.
            Unless you are sure that you are set for 100% Solar
            heating, with inefficient double hung windows, you
            will do better to avoid them. You can get much
            better venting of the sunspace (both higher and lower
            for greater stack effect, plus more vent area, and for
            less cost) by having doors at both ends, with full
            view screens. Lowe's and other stores have fairly
            nice, basic, full-view storm/screen doors for just
            not much over $100. You can then use salvaged
            sliding glass door glass on your south wall, giving
            you and your plants a lot more light, and Solar
            efficiency, for what will usually be a lower total
            cost. However, for optimum venting, you will
            need the door, plus some sort of top vents, as
            high as you can put them. Other wise, the
            warmest air will still be trapped.

            Posted by: "David Gray" ndgray@...

            >We really need to express this as some kind of complex
            > rate of glazing (single vs double) versus total surface area
            > versus latitude and climate.

            You might read my article in the Jan2005 issue of ESSN
            at: www.rebelwolf.con/essn/ESSN-Jan2005.pdf

            > should be some ideal size determined as mathematically
            > as possible.

            There definitely is. However, it is specific to the house, and
            many of other factors, so it takes time, and knowledge. I have
            been studying it, and doing it for a living for the past thirty-plus
            years. I have found no good shortcuts, for real designing.
            They only work well in general conversation.

            -Laren Corie-
            Natural Solar Building Design Since 1975
            www.ThermalAttic.com

            Read my Solar house design articles in:
            -Energy Self-Sufficiency Newsletter-
            www.rebelwolf.com

            Home base:
            LittleHouses YahooGroup
            http://groups.yahoo.com/group/LittleHouses/
          • RT
            ... Then I would strongly suggest re-siting and/or re-orienting and/or re- designing the house so that it can take advantage of winter solar gains. To not do
            Message 5 of 17 , Jan 3, 2009
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              --- In SB-r-us@yahoogroups.com, "orleansdonna" <orleansdonna@...>
              wrote:

              > I pretty much have determined that my house's location on its lot
              > is not going to get a ton of winter solar gain.

              Then I would strongly suggest re-siting and/or re-orienting and/or re-
              designing the house so that it can take advantage of winter solar
              gains.

              To not do so with a new house built in Ontario Canada in the year 2k
              +9 would be, to be blunt, foolish. If it were an existing building in
              the city on a difficult lot, there might be some justification for
              not doing so but on a new home on a rural site ?

              A well insulated/competently air-sealed/properly sited/properly
              oriented 1200 sf normal-looking (ie typical number of normal, modest-
              sized equator-facing windows) house built in this area should easily
              get 60-75% or more of its total heating load supplied by direct gain
              passive solar.

              On days like we've been having this week, a new house in the Ottawa
              area should not require any auxiliary heating at all until just
              before bedtime, if at all, to maintain temperatures in the standard
              range of comfort (18-22 degC).

              === * ===
              Rob Tom
              Kanata, Ontario, Canada
              < A r c h i L o g i c at chaffYahoo dot ca>
              (manually winnow the chaff from my edress in your reply)
            • Islander -- born & bred
              There are alternate ways of utilizing solar gain, if it s not possible to orient your home for maximum southern exposure. Consider using something which at
              Message 6 of 17 , Jan 3, 2009
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                There are alternate ways of utilizing solar gain, if it's not possible
                to orient your home for maximum southern exposure. Consider using
                something which at least provides supplemental heating and reduces
                reliance and costs for fossil fuels, like a Cansolair hot air panel.
                ... an area of approximately 1000 sq. ft. can be heated to a comfortable
                temperature with just 15 minutes of sun per hour. ... [considered] a
                supplemental heating system and is not intended to be the
                sole component in a heating system but to provide FREE heat
                when the sun is shining. I've included links to information from local
                supplier & testimonials from some of their customers who have installed
                it in their homes.
                http://www.renewablelifestyles.ca/products.htm
                <http://www.renewablelifestyles.ca/products.htm>
                http://www.renewablelifestyles.ca/testimonials.htm
                <http://www.renewablelifestyles.ca/testimonials.htm>
                Incidentally, if you've been following the weather in Atlantic Canada
                lately, you'll know we've had 100 km± winds and -20ºC+ windchills
                here on P. E. I. that really suck heat out of structures!
                >
                > > I pretty much have determined that my house's location on its lot
                > > is not going to get a ton of winter solar gain.
                >
                > Then I would strongly suggest re-siting and/or re-orienting and/or re-
                > designing the house so that it can take advantage of winter solar
                > gains.
                >
                > --- In SB-r-us@yahoogroups.com, "orleansdonna" orleansdonna@
                > wrote:
                >
                > To not do so with a new house built in Ontario Canada in the year 2k
                > +9 would be, to be blunt, foolish. If it were an existing building in
                > the city on a difficult lot, there might be some justification for
                > not doing so but on a new home on a rural site ?
                >
                > A well insulated/competently air-sealed/properly sited/properly
                > oriented 1200 sf normal-looking (ie typical number of normal, modest-
                > sized equator-facing windows) house built in this area should easily
                > get 60-75% or more of its total heating load supplied by direct gain
                > passive solar.
                >
                > On days like we've been having this week, a new house in the Ottawa
                > area should not require any auxiliary heating at all until just
                > before bedtime, if at all, to maintain temperatures in the standard
                > range of comfort (18-22 degC).
                >
                > === * ===
                > Rob Tom
                > Kanata, Ontario, Canada
                > < A r c h i L o g i c at chaffYahoo dot ca>
                > (manually winnow the chaff from my edress in your reply)
                >



                [Non-text portions of this message have been removed]
              • Caralee
                Laren, Would you still say the double-hung windows are a bad idea if you knew there were many of them, creating a solid bank of glass one after another along a
                Message 7 of 17 , Jan 3, 2009
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                  Laren,
                  Would you still say the double-hung windows are a bad idea if you knew there were many of them, creating a solid bank of glass one after another along a very long south-facing wall? It seems then there would be more light than you describe. I do agree, however, with the east-west ventilation, and we are definitely planning for that already.
                  Caralee
                  ----- Original Message -----
                  From: LarenCorie
                  To: SB-r-us@yahoogroups.com
                  Sent: Friday, January 02, 2009 11:20 AM
                  Subject: [SB-r-us] Re: Exasperation!!


                  Posted by: "Caralee" cgwoods@...

                  > we are planning a south-facing greenhouse on our home,
                  > and will be using double-hung windows which will allow
                  > us to open both tops and bottoms of the windows for
                  > ventilation when needed.

                  Hello Caralee

                  Double hung windows are pretty much in the "terrible"
                  range, as south facing windows, for Solar heating. There
                  are three very serious problems, with their general design.

                  .


                  [Non-text portions of this message have been removed]
                • orleansdonna
                  Thank you for those kind words. It s a difficult lot. Many trees and much granite, so short of blasting and clear-cutting, I have done my utmost to site the
                  Message 8 of 17 , Jan 3, 2009
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                    Thank you for those kind words.

                    It's a difficult lot. Many trees and much granite, so short of
                    blasting and clear-cutting, I have done my utmost to site the home
                    appropriately with south facing exposure, appropriate glass to mass
                    ratios, design which allows for cross ventilation, natural wind
                    shelter from existing vegetation and overhangs which was what my
                    original question was. And I'm no designer, just a novice house
                    builder who is trying my best.

                    Donna


                    --- In SB-r-us@yahoogroups.com, "RT" <archilogic@...> wrote:
                    >
                    > --- In SB-r-us@yahoogroups.com, "orleansdonna" <orleansdonna@>
                    > wrote:
                    >
                    > > I pretty much have determined that my house's location on its lot
                    > > is not going to get a ton of winter solar gain.
                    >
                    > Then I would strongly suggest re-siting and/or re-orienting and/or
                    re-
                    > designing the house so that it can take advantage of winter solar
                    > gains.
                    >
                    > To not do so with a new house built in Ontario Canada in the year 2k
                    > +9 would be, to be blunt, foolish. If it were an existing building
                    in
                    > the city on a difficult lot, there might be some justification for
                    > not doing so but on a new home on a rural site ?
                    >
                    > A well insulated/competently air-sealed/properly sited/properly
                    > oriented 1200 sf normal-looking (ie typical number of normal,
                    modest-
                    > sized equator-facing windows) house built in this area should
                    easily
                    > get 60-75% or more of its total heating load supplied by direct
                    gain
                    > passive solar.
                    >
                    > On days like we've been having this week, a new house in the Ottawa
                    > area should not require any auxiliary heating at all until just
                    > before bedtime, if at all, to maintain temperatures in the standard
                    > range of comfort (18-22 degC).
                    >
                    > === * ===
                    > Rob Tom
                    > Kanata, Ontario, Canada
                    > < A r c h i L o g i c at chaffYahoo dot ca>
                    > (manually winnow the chaff from my edress in your reply)
                    >
                  • John Barlow
                    ... The best (relocating the house site) may not be easy, but you can live in a less than optimal site - you might have to spend more (perhaps as much as the
                    Message 9 of 17 , Jan 3, 2009
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                      orleansdonna wrote:
                      > ... I pretty much have determined that my house's location
                      > on its lot is not going to get a ton of winter solar gain. ...

                      The best (relocating the house site) may not be easy, but you can live
                      in a less than optimal site - you might have to spend more (perhaps as
                      much as the explosives and tree clearing). You can put in raised solar
                      panels that face the equator, and either pump air or water through the
                      panels to heat the house. Plus you can install a heliostat (a
                      reflector, such as polished stainless steel) to reflect sun into the
                      house (strong structure to avoid wind damage) - see
                      http://www.derekwrigleydesign.id.au/Book_review.shtml for a small
                      discussion of a retro-fitted heliostat to a poorly designed house.

                      Having said all that, I still "vote" (not that a vote is worth anything
                      - it's your house) to have a good look at relocating the house. Free
                      energy from the sun is not to be ignored.


                      John Barlow
                      straw-bale owner-builder
                      http://www.guru.com.au/farm/
                    • RT
                      ... ofblasting ... More kind words... As my sig indicates, I live in (rural) Kanata. I tell people that the cattle around here have pointy heads from trying to
                      Message 10 of 17 , Jan 7, 2009
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                        --- In SB-r-us@yahoogroups.com, "orleansdonna" <orleansdonna@...>
                        wrote:
                        --- In SB-r-us@yahoogroups.com, "orleansdonna" <orleansdonna@...>
                        wrote:
                        >
                        > Thank you for those kind words.
                        >It's a difficult lot. Many trees and much granite, so short
                        ofblasting
                        > and clear-cutting,

                        More kind words...

                        As my sig indicates, I live in (rural) Kanata.

                        I tell people that the cattle around here have pointy heads from
                        trying to graze between the rocks of this terrain which in many areas
                        is the exposed granite of the Canadian Shield.

                        And yet, trees still manage to somehow send roots down and grow to a
                        size where the trunks girth is greater than four adults holding hands
                        can get their collective arms around.

                        In recent years I have seen the countryside around me getting eaten
                        up by homebuilding activity as the city moves out this way.

                        One of the most common mistakes that I see is people buying
                        properties because they are smitten by the gorgeous woods and want to
                        build their home "in amongst the trees" .

                        More often than not, they'll select the most charming spot in the
                        woods for the site of their home, usually where the trees are mature
                        enough to be considered majestic.

                        Then they'll spend a few weekends cutting down trees, keeping the
                        swath of clear-cut as close to the building footprint as possible so
                        as to minimise the number of trees to be taken down.

                        And then more trees have to be cut down to create a nice winding
                        path from the road access. And then they find that the nice winding
                        path needs to be widened so that large trucks can get in to the site.

                        And then more trees have to be cut down at the house site so that
                        trucks and equipment have room to manouevre.

                        And then major roots of the trees at the perimeter of the clearing
                        get butchered/damaged/severed and they eventually get taken down.

                        As the building progresses, more trees get taken down because their
                        limbs or roots impede the process.

                        Then comes the realisation that a raised bed filter media-type septic
                        field needs to be built on top of the rock because their is little or
                        no soil overburden in which to accommodate a conventional septic
                        field.

                        More trees come down.

                        Then comes the 200 dump-truck loads of fill to conceal the septic
                        field lump and bury the foundation .

                        More trees come down.

                        Then another clear-cut swath through to the road to accommodate the
                        tie to the electrical grid supply line.

                        By the time the house is built and final grading around the house is
                        done, they have effectively destroyed that which attracted them to
                        the site in the first place.

                        And to add insult to injury, in the subsequent years following
                        completion of the house, mature trees around the house site keep
                        dying, one after the other because their once sheltered-by-dense-
                        woods root zones are exposed to sun and in many cases have to be
                        taken down by professional arbourists because of the damage to the
                        house that could result if the tree fell the wrong way, as often
                        happens when those not experienced at felling trees try to do so.

                        Moral of the story:

                        Site the house on the worst, most unattractive part of the site and
                        engage in site repair after the house is built, sculpting the earth
                        and vegetation to suit (since you will be importing a hundred or more
                        truckloads of earth in) and to accommodate new, large caliper trees
                        that you've rescued, either from your site or from other nearby
                        construction sites (ie roadwork, fieldwork, suburban developments)
                        where the trees would otherwise have been cut down.


                        === * ===

                        And another common mistake that I see is people trying to deal with
                        rocky terrain by blasting the rock away in order to put in a
                        foundation. Or worse, having a huge excavator with a jack-hammer
                        attachment pounding away for a week or more to break up the rock.

                        Build on top of the rock and bring in earth + organic matter to
                        sculpt the terrain to suit, again engaging in site repair and
                        improvement.

                        Excavation companies are always looking for dumping sites and if you
                        can take a few hundred truckloads, they'll often deliver it for free.
                        (On a rocky site, a couple hundred truckloads of fill doesn't go very
                        far.)

                        === * ===

                        And some more kind words:

                        I realise that you (Donna) are probably a novice at house design but
                        that doesn't mean you still shouldn't try to get it right.

                        Design is a process of constant evaluation of ideas and tossing out
                        of ideas even if they've involved a lot of time to get to that point.

                        Even professionals who have been doing it for a lifetime have to (or
                        should if they're doing a good job) be willing to not cling to bad
                        ideas despite being heavily invested in them.

                        For a novice (ie no formal training, no years of experience, no years
                        of independent research) to expect to whip out a competent design
                        without having to do major revisions and/or tossing out of what is
                        essentially preliminary conceptual work, is unrealistic.

                        Designing a house is a lot like getting pregnant.

                        You can't just be a little bit pregnant and once pregnant, you can't
                        slough off the responsbility of doing all that is possible to ensure
                        that the newborn will be the best that it can be.

                        Not doing so will have consequences well into the future, for more
                        than just one generation.

                        And I'm pretty sure that everyone who has become pregnant was a
                        novice at being such, at least once.

                        --
                        === * ===
                        Rob Tom
                        Kanata, Ontario, Canada
                        < A r c h i L o g i c at chaffYahoo dot ca>
                        (manually winnow the chaff from my edress in your reply)
                      • Lee Gilbert
                        ... I remember when I was a little girl spending my Summers out in Kanata, reading a book about a family moving to Cananda in the 1800 s where the woman begged
                        Message 11 of 17 , Jan 9, 2009
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                          --- In SB-r-us@yahoogroups.com, "RT" <archilogic@...> wrote:
                          >

                          > As my sig indicates, I live in (rural) Kanata.....

                          > And to add insult to injury, in the subsequent years following
                          > completion of the house, mature trees around the house site keep
                          > dying, one after the other because their once sheltered-by-dense-
                          > woods root zones are exposed to sun and in many cases have to be
                          > taken down by professional arbourists because of the damage to the
                          > house that could result if the tree fell the wrong way, as often
                          > happens when those not experienced at felling trees try to do so.
                          >
                          > Rob Tom
                          > Kanata, Ontario, Canada

                          I remember when I was a little girl spending my Summers out in
                          Kanata, reading a book about a family moving to Cananda in the 1800's
                          where the woman begged the workers to save some of the trees being
                          felled around her new log cabin wanting them for shade and beauty.
                          But she was told that unless the trees had grown without the shelter
                          of other trees, their roots would be too shallow to support them once
                          the other trees around had been felled, and would be likely to fall
                          on their house! Better to clear cut and replant, they said. Her
                          husband was a British army officer and there was some great
                          descriptions of canoeing with the local indians and her new life
                          there, I wish I could read it again.
                          I have always wondered, how do you know when you have to take out
                          rock to make a foundation or if it is ok to use the rock as it is?
                          One book I have says that if you take a thin metal rod and lean all
                          your weight on it, and it barely marks the ground, then it is stable
                          enough for a foundation so surely in that case most rock would be
                          find just where it is? We will be digging some trial holes on our
                          land in the Spring to try and answer questions about foundations here
                          for another build we are planning.
                          I looked at Kanata on Google Earth the other evening, man it has
                          grown! It was all very new and quite small then I was there. Where
                          are the cornfields and old abandoned school house that I used to bike
                          to?

                          Lily in Bulgaria
                        • alafau
                          ... Funnily enough not long ago I read at a website on Vaastu the ancient Vedic art of building construction, that you should never build your house in the
                          Message 12 of 17 , Jan 9, 2009
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                            --- In SB-r-us@yahoogroups.com, "Lee Gilbert" <lee@...> wrote:
                            >
                            > --- In SB-r-us@yahoogroups.com, "RT" <archilogic@> wrote:
                            > >
                            Funnily enough not long ago I read at a website on "Vaastu" the
                            ancient Vedic art of building construction, that you should never
                            build your house in the shadow of a tree. FWIW

                            Alan


                            > > As my sig indicates, I live in (rural) Kanata.....
                            >
                            > > And to add insult to injury, in the subsequent years following
                            > > completion of the house, mature trees around the house site keep
                            > > dying, one after the other because their once sheltered-by-dense-
                            > > woods root zones are exposed to sun and in many cases have to be
                            > > taken down by professional arbourists because of the damage to the
                            > > house that could result if the tree fell the wrong way, as often
                            > > happens when those not experienced at felling trees try to do so.
                            > >
                            > > Rob Tom
                            > > Kanata, Ontario, Canada
                            >
                            > I remember when I was a little girl spending my Summers out in
                            > Kanata, reading a book about a family moving to Cananda in the 1800's
                            > where the woman begged the workers to save some of the trees being
                            > felled around her new log cabin wanting them for shade and beauty.
                            > But she was told that unless the trees had grown without the shelter
                            > of other trees, their roots would be too shallow to support them once
                            > the other trees around had been felled, and would be likely to fall
                            > on their house! Better to clear cut and replant, they said. Her
                            > husband was a British army officer and there was some great
                            > descriptions of canoeing with the local indians and her new life
                            > there, I wish I could read it again.
                            > I have always wondered, how do you know when you have to take out
                            > rock to make a foundation or if it is ok to use the rock as it is?
                            > One book I have says that if you take a thin metal rod and lean all
                            > your weight on it, and it barely marks the ground, then it is stable
                            > enough for a foundation so surely in that case most rock would be
                            > find just where it is? We will be digging some trial holes on our
                            > land in the Spring to try and answer questions about foundations here
                            > for another build we are planning.
                            > I looked at Kanata on Google Earth the other evening, man it has
                            > grown! It was all very new and quite small then I was there. Where
                            > are the cornfields and old abandoned school house that I used to bike
                            > to?
                            >
                            > Lily in Bulgaria
                            >
                          • LarenCorie
                            Posted by: Caralee cgwoods@hughes.net ... Hi Caralee; Definitely. It has absolutely nothing to do with the number of windows, except that making the same
                            Message 13 of 17 , Jan 9, 2009
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                              Posted by: "Caralee" cgwoods@...

                              > Would you still say the double-hung windows are a bad idea
                              > if you knew there were many of them, creating a solid bank of
                              > glass one after another along a very long south-facing wall?

                              Hi Caralee;

                              Definitely. It has absolutely nothing to do with the number of
                              windows, except that making the same mistake many times is
                              just that much worse. If they lose heat instead of collecting,
                              then it is like the old joke about " I lose money on every sale,
                              but I make up for it in volume" Beside there simply is no such
                              thing as "a solid bank of glass" when using double hung windows.
                              A typical double hung window will only have about 60% as
                              much glass area, in the same area of wall, compared to fixed
                              glass. Then block 30% of that with screens, andd the shadow
                              of the upper sash, and you get less than half the Solar gain.

                              Shaded glass, like is created by double hung windows, is
                              about the least energy efficient wall you can have, in winter.
                              It does not take very much of it, to totally negate the Solar
                              advantage of the sunlit glass. Screens do not significantly
                              reduce heat loss, but they do significantly reduce Solar gain.

                              I have measures the wire/thread diameters of three screens,
                              and also research it online. Thread/wire diameters vary in standard
                              (non-solar blocking) window screens, from 11/1000 in, for bronze
                              and 10/1000in for aluminum, down to about 7/1000in for very thin
                              fiberglass. I have found reference, that 0.20mm (8/1000in) is the
                              standard thickness. So, using that as a guide, a standard 16x18
                              insect screen will block 25% of light, shining directly through it.
                              However, sunlight does not work that way, becasue the sun is
                              never on the horizon, due south, except in the polar regions.
                              If we take an average Solar altitude of 30°, and an average
                              azimuth of 20° we get an average angle of incident of over
                              34° which increases that 25% shade factor to over 30%.
                              So, if your outdoor temperature is 40° colder than indoors,
                              with 300BTU/day of sunlight, on a semi cloudy day, shining
                              on your 75% transmittance, R2 windows, your gain would
                              be 214BTU without the screen, and less than 150 with it.
                              During that same six hours, the heat loss is 6x40/2 = 120.
                              So, the net gain without the screen is 214-120 = 94BTU/ft²
                              The screened window will give you 150-120 = 30BTU/ft²
                              That is (68% less) That does not even include the shading
                              by the deep setting of the glass, or the screen frame. I think
                              that a 50% reduction in net Solar gain, for using double
                              hung windows, instead of fixed glass, is more than fair
                              for the double hung windows.

                              As you can see in these Andersen section drawings, the
                              upper sash, and screens frame, will definitely shade the
                              glass of the lower sash.

                              http://www.andersenwindows.com/servlet/Satellite/AW/AWProduct/awProductDetail/AWProduct/1135095639066/1102951372825?tab=6-3&tabname=&tableftnav=Basic%20Unit%20&%20Rough%20Opening%20Details

                              > It seems then there would be more light than you describe.

                              No. Double hung windows, and their screen block the same
                              percentage of light, whether it is one window, or thousands.
                              And, though more windows might bring in more light, they
                              also let out more heat. You can have a lot more glass area,
                              using fixed glass. The best way that I have found, to build
                              windows for Solar gain is a timber frame, and fixed glass,
                              with some operable units, for ventilation, usually awning
                              windows.

                              > I do agree, however, with the east-west ventilation, and
                              > we are definitely planning for that already.

                              Agree or not. That is up to you. I am just openly sharing
                              my 30+ years of experience. It is completely up to you
                              to take advantage of it, or ignore it.


                              -Laren Corie-
                              Natural Solar Building Design Since 1975
                              www.ThermalAttic.com

                              Read my Solar house design articles in:
                              -Energy Self-Sufficiency Newsletter-
                              www.rebelwolf.com

                              Home base:
                              LittleHouses YahooGroup
                              http://groups.yahoo.com/group/LittleHouses/
                            • RT
                              ... In quickly scanning through the recent messages in the archives I spotted some excellent questions (posed as comments) that I felt deserved to be
                              Message 14 of 17 , Jan 11, 2009
                              • 0 Attachment
                                --- In SB-r-us@yahoogroups.com, "Lee Gilbert" <lee@...> wrote:

                                In quickly scanning through the recent messages in the archives I
                                spotted some excellent questions (posed as comments) that I felt
                                deserved to be addressed.

                                One person mentioned that (s)he was struggling with "systems"
                                presumably meaning the mechanical systems. I would encourage the
                                person(s) who mentioned that to start a thread on that topic with
                                questions that deal with specific issues and hopefully, herds of
                                Listmembers will jump in on the topic since most of us have close-up
                                and personal experiences with mechanical systems in our daily lives
                                and will likely have thoughts/ opinions/suggestion/wisdom on the
                                matter.

                                The most recent specific question that I saw was from Lily in
                                Bulgaria (but who apparently calls herself Lee Gilbert in the UK)

                                "Lee Gilbert" <lee@d....co.uk> wrote:

                                > I have always wondered, how do you know when you have to take out
                                > rock to make a foundation or if it is ok to use the rock as it is?
                                > One book I have says that if you take a thin metal rod and lean all
                                > your weight on it, and it barely marks the ground, then it is stable
                                > enough for a foundation

                                I have my doubts about the efficacy of the "leaning on thin metal rod
                                test for determining suitability of rock strata for a foundation.

                                It might tell you how hard the rock is (ie Google "Moh's Scale of
                                Hardness") but it wouldn't reveal much about the stability of that
                                rock.

                                For instance, the underlying rock strata here in Kanata is granite.
                                In my particular area, fortunately there is a depression in the
                                granite in which sits a pocket of sandstone.
                                "Fortunate" because water flows more easily through sandstone than it
                                does through granite.
                                I (or more correctly, the well driller) hit a water table at 25 feet
                                down and another at 40 feet down and the well yields a flow rate far
                                in excess of what we'd ever need.

                                OTOH, just two concession roads over from my home, beyond the pocket
                                of sandstone, it's common to drill wells that are 300 to 800 ft deep
                                into the granite only to yield a trickle of water. In some instances
                                people have drilled to depths of ~1200 feet only to hit saline water,
                                remnants of the prehistoric seas that used to cover this area.

                                Oddly enough, the blasting guys who use boring machines to drill
                                holes into the rock in order to plant their explosive charges tell me
                                that the sandstone wears out their diamond bits a lot faster than
                                when drilling into granite.

                                And the excavator operators with jack hammer attachments bigger than
                                a phone booth mounted on (in place of the Volkswagen Beetle-sized
                                shovels), tell me that it's more difficult to break up sandstone than
                                it is granite. ie Sandstone tends to simply crush into a powder under
                                the repeated impact of the relatively blunt jackhammer bit (not
                                really a "bit" because it's bigger than a horse's head) whereas
                                granite will eventually fracture.

                                But I digress. Both the sandstone and the granite would pass the
                                "leaning on thin rod" test.

                                However, if one sweeps away the light dusting of often silty
                                "topsoil" it would be entirely possible to find that the rock you're
                                standing on may be a fragment of rock, the size of which may be the
                                size of a dining room table and only a foot or so thick or it might
                                be the size of a minivan.

                                In both instances, I'd say that they should probably be moved rather
                                than built upon.

                                If it's a collection of minivan-sized (and larger) fragments (ie
                                parts of what would otherwise be a larger whole if uncracked) it'd
                                likely be fine to build on.

                                Bottom line is that it's pretty much necessary to do some digging
                                over a fairly large area of the prospective building site to see
                                exactly what it is that you've got underfoot.

                                --
                                === * ===
                                Rob Tom
                                Kanata, Ontario, Canada
                                < A r c h i L o g i c at ChaffY a h o o dot C a >
                                (manually winnow the chaff from my edress in your reply)
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