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re: suggestions for dream house design
29 may 1996
wrote:
>gjessup@nznet.gen.nz (graeme jessup) wrote:
>> wstewart@patriot.net says...
>> >peipp wrote:
>> >> i'm planning to build my dream house this summer and fall. my idea of a
>> >> dream house is one that has the following attributes: low cost, labor,
>> >> maintenance, and minimum enviromental impact and utility usage(electric,
>> >> propane, wood), while still being comfortable to live in. i'm going to use
>> >> as much used materials as possible and am shooting for a cost of
>> >> $5-10/ft^2. i will be doing all of the construction myself.
>> >
>> >the most important initial investment you can make right now is purchasing
>> >last year's back issues of home power magazine 800-707-6585. there are even
>> >back issues on the web.
>
>good suggestion.
perhaps home power has changed. last time i looked, it was full of pv nuts.
i noticed "low cost," above, but didn't detect any off-the-grid-o-mania in
the original posting :-)
>> >> i'm looking for constructive ideas, comments, and suggestions to improve
>> >> the design, especially in the areas of heating, cooling, and reducing
>> >> labor.
>> >
>> >home energy magazine is perfect for this as well.
i subscribed to home energy once. it seemed to be dedicated to helping
people in the business of doing energy audits for electric utilities,
for profit. has it changed?
>> >> the current plans call for a lot of south facing glazing for solar gain,
>> >> 5- 3x8 downstairs windows and 4- 3x5 upstairs windows.
>
>plan on moveable insulation for your windows and isolating that area from
>from the living space when the sun goes down and the room begins to cool.
>also plan on shading the windows in the summer.
why mess with movable insulation if you have a door in an insulated wall?
my impression is that r4 movable insulation costs about $5/ft^2, plus
installation. does anyone have better numbers?
>> >> after seeing all the posts concerning solar rooms and closets i'm now
>> >> wondering if i could get by without backup heat and maybe even eliminate
>> >> the propane water heater.
>
>don't bank on it.
at this point, it seems to me we can design an inexpensive 100% solar house
practically anywhere, using nrel weather data and simple physics :-) norman
saunders, pe, has been building inexpensive 100% solar houses since 1944,
houses with no other form of heat, in cold, cloudy new england, some of which
have long track records.
>> >>i still haven't fully grasp the solar closet concept however.
>
>i'm not sure that anyone but nick has yet.
ask me a question, if you like. quite a few others understand this now,
including the technical review committee of the world renewable energy
congress to be held in denver from june 16-21.
>ask for some real world data from any solar closets actually in existance.
here's the first data we took last fall. very preliminary, but real data...
ambient house sunspace drum sun power elec power
temp (f) temp (f) temp (f) temp (f) (w/m^2) (w)
11/04 00:05 50.5 65.0 60.1 73.3 1 12
11/04 00:10 50.0 64.8 60.1 73.3 1 12
11/04 00:15 49.8 64.6 60.0 73.3 1 12
11/04 00:20 50.2 64.9 59.9 73.3 1 12
11/04 00:25 49.8 65.0 59.9 73.3 1 12
11/04 00:30 49.3 64.6 59.8 73.2 1 13
11/04 00:35 49.4 64.6 59.8 73.2 1 12
11/04 00:40 48.9 64.4 59.5 73.2 1 12
11/04 00:45 48.6 64.3 59.6 73.2 1 13
11/04 00:50 48.8 64.3 59.5 73.1 1 13
11/04 00:55 48.3 63.7 59.3 73.1 1 13
11/04 01:00 47.8 63.6 59.1 73.1 1 13
11/04 01:05 48.1 63.6 59.0 73.0 1 13
11/04 01:10 47.9 63.6 58.9 73.0 1 13
11/04 01:15 47.6 63.9 58.9 73.0 1 27
11/04 01:20 47.5 63.3 58.9 73.0 1 13
11/04 01:25 47.6 63.4 59.0 73.0 1 13
11/04 01:30 47.2 63.3 58.8 72.9 1 13
11/04 01:35 47.6 63.3 58.7 72.9 1 13
11/04 01:40 47.1 63.8 58.6 72.9 1 27
11/04 01:45 47.5 63.7 58.6 72.9 1 12
11/04 01:50 47.1 63.3 58.6 72.9 1 13
11/04 01:55 47.2 62.9 58.6 72.8 1 13
11/04 02:00 46.8 63.3 58.6 72.8 1 28
11/04 02:05 46.8 63.1 58.6 72.8 1 13
11/04 02:10 46.6 62.9 58.6 72.7 1 13
11/04 02:15 46.8 63.2 58.6 72.7 1 27
11/04 02:20 46.5 63.3 58.5 72.7 1 13
11/04 02:25 46.0 62.7 58.3 72.7 1 13
11/04 02:30 46.6 63.4 58.4 72.7 1 28
11/04 02:35 45.7 62.9 58.4 72.6 1 13
11/04 02:40 46.4 63.2 58.3 72.6 1 31
11/04 02:45 45.6 62.7 58.2 72.6 1 13
11/04 02:50 45.5 62.8 57.9 72.6 1 13
11/04 02:55 45.0 62.6 57.8 72.5 1 25
11/04 03:00 44.6 62.8 57.7 72.5 1 13
11/04 03:05 44.2 62.3 57.5 72.5 1 13
11/04 03:10 44.2 62.2 57.2 72.4 1 28
11/04 03:15 43.7 61.7 57.1 72.4 1 13
11/04 03:20 43.5 61.6 56.9 72.4 1 28
11/04 03:25 43.6 62.2 56.9 72.4 1 13
11/04 03:30 44.1 62.1 57.0 72.4 1 13
11/04 03:35 43.2 62.6 57.0 72.3 1 32
11/04 03:40 43.3 62.3 57.1 72.3 1 13
11/04 03:45 43.2 62.5 57.0 72.3 1 13
11/04 03:50 42.5 62.2 56.8 72.3 1 13
11/04 03:55 42.1 62.0 56.8 72.2 1 30
11/04 04:00 42.1 61.6 56.7 72.2 1 12
11/04 04:05 42.1 61.8 56.5 72.2 1 13
11/04 04:10 42.0 61.8 56.4 72.1 1 26
11/04 04:15 42.0 62.1 56.4 72.1 1 13
11/04 04:20 42.6 62.4 56.4 72.1 1 26
11/04 04:25 42.1 62.4 56.4 72.1 1 13
11/04 04:30 42.4 62.4 56.3 72.1 1 12
11/04 04:35 42.6 62.2 56.3 72.1 1 13
11/04 04:40 41.7 62.1 56.3 72.0 1 21
11/04 04:45 41.1 61.6 56.3 72.0 1 13
11/04 04:50 41.1 62.0 56.2 72.0 1 31
11/04 04:55 40.7 62.1 56.1 72.0 1 13
11/04 05:00 40.3 61.6 55.9 71.9 1 13
11/04 05:05 40.4 61.1 55.7 71.9 1 13
11/04 05:10 40.0 61.1 55.5 71.8 1 24
11/04 05:15 40.1 60.7 55.3 71.8 1 13
11/04 05:20 40.1 61.2 55.3 71.8 1 24
11/04 05:25 42.0 61.5 55.3 71.8 1 13
11/04 05:30 40.3 61.1 55.3 71.8 1 25
11/04 05:35 39.9 61.1 55.2 71.7 1 13
11/04 05:40 39.5 60.6 55.0 71.7 1 13
11/04 05:45 39.3 60.9 54.8 71.6 1 28
11/04 05:50 40.3 60.8 54.7 71.6 1 13
11/04 05:55 41.0 61.2 54.7 71.6 1 13
11/04 06:00 39.5 61.1 54.8 71.6 1 28
11/04 06:05 39.0 60.7 54.8 71.6 1 12
11/04 06:10 39.4 60.5 54.7 71.5 1 12
11/04 06:15 40.3 61.3 54.7 71.5 1 30
11/04 06:20 39.8 60.7 54.7 71.5 0 13
11/04 06:25 40.0 60.7 54.7 71.5 1 13
11/04 06:30 39.5 60.9 54.6 71.4 1 29
11/04 06:35 39.6 60.8 54.5 71.4 3 (dawn) 12
11/04 06:40 38.4 60.4 54.4 71.4 6 29
11/04 06:45 38.5 60.1 54.2 71.3 9 13
11/04 06:50 38.6 60.1 54.2 71.3 12 12
11/04 06:55 38.5 60.1 54.2 71.3 14 30
11/04 07:00 38.1 59.2 54.2 71.2 17 13
11/04 07:05 38.8 59.8 54.3 71.2 20 28
11/04 07:10 39.0 59.9 54.4 71.2 24 12
11/04 07:15 38.6 59.8 54.3 71.2 26 26
11/04 07:20 39.8 60.2 54.5 71.1 29 12
11/04 07:25 38.7 59.7 54.6 71.1 31 25
11/04 07:30 39.8 59.9 54.6 71.1 37 12
11/04 07:35 41.2 60.6 54.6 71.1 88 29
11/04 07:40 40.0 60.5 54.9 71.1 248 12
11/04 07:45 41.7 60.5 57.7 71.0 407 12
11/04 07:50 41.8 61.3 63.5 71.0 449 28
11/04 07:55 40.9 60.8 68.3 71.0 480 12
11/04 08:00 40.2 60.6 72.0 71.0 511 16
11/04 08:05 39.5 60.8 75.5 71.1 534 33
11/04 08:10 41.1 62.4 79.6 71.2 553 23
11/04 08:15 40.8 62.4 82.4 71.3 572 24
11/04 08:20 40.4 62.5 85.2 71.4 598 35
11/04 08:25 40.5 63.0 87.9 71.5 617 35
11/04 08:30 40.4 63.6 90.8 71.6 635 35
11/04 08:35 41.0 64.9 93.9 71.7 655 35
11/04 08:40 40.9 65.7 96.9 71.8 675 35
11/04 08:45 40.6 65.5 99.7 71.8 693 34
11/04 08:50 41.4 66.2 101.6 71.9 709 34
11/04 08:55 41.1 66.6 104.0 72.0 726 34
11/04 09:00 41.2 66.8 106.6 72.1 744 34
11/04 09:05 42.1 67.6 109.0 72.2 757 34
11/04 09:10 41.9 68.3 111.5 72.4 772 34
11/04 09:15 41.9 68.3 113.3 72.5 789 34
11/04 09:20 41.8 69.1 114.7 72.6 805 34
11/04 09:25 42.2 69.6 116.3 72.7 819 34
11/04 09:30 43.0 70.5 118.2 72.8 833 34
11/04 09:35 43.4 72.1 120.4 73.0 847 34
11/04 09:40 43.0 71.9 121.2 73.1 855 34
11/04 09:45 44.2 72.6 121.2 73.2 866 34
11/04 09:50 43.7 72.1 122.0 73.4 876 34
11/04 09:55 43.2 72.8 122.5 73.5 888 34
11/04 10:00 43.4 74.1 123.9 73.6 895 34
11/04 10:05 44.3 75.3 124.6 73.8 882 34
11/04 10:10 43.7 74.7 124.5 73.9 921 34
11/04 10:15 46.0 76.7 126.3 74.0 925 33
11/04 10:20 44.9 77.2 126.6 74.2 813 33
11/04 10:25 47.1 77.8 122.2 74.2 849 33
11/04 10:30 47.4 78.4 125.2 74.4 969 33
11/04 10:35 46.4 78.5 126.8 74.6 977 33
11/04 10:40 46.3 78.0 126.9 74.7 901 33
11/04 10:45 45.6 78.9 126.9 74.9 878 33
11/04 10:50 45.2 78.7 126.1 75.0 927 33
11/04 10:55 45.4 77.9 123.6 75.0 809 33
11/04 11:00 46.0 78.5 129.0 75.2 1029 33
11/04 11:05 47.3 80.9 130.9 75.5 868 32
11/04 11:10 46.7 80.6 123.2 75.4 854 33
11/04 11:15 46.7 80.9 126.4 75.6 898 33
11/04 11:20 47.7 81.6 124.5 75.7 796 33
11/04 11:25 48.4 82.9 127.4 75.8 959 33
11/04 11:30 47.7 83.0 129.5 76.1 992 33
11/04 11:35 48.9 83.1 127.4 76.3 676 33
11/04 11:40 49.2 82.4 116.9 76.0 507 33
11/04 11:45 45.9 80.8 122.9 76.0 990 33
11/04 11:50 45.7 80.1 122.9 76.3 686 33
11/04 11:55 46.5 81.1 125.6 76.4 1041 34
11/04 12:00 47.0 82.1 125.4 76.8 788 34
>> >where would you put 30 55-gallon drums?
>
>make sure you can get to them to replace them when they leak.
it's a good idea to be able to top them up if they lose some water by
evaporation over the years, through their non-hermetically sealed bungs,
but plastic drums should last a very long time. steve baer's metal drums
lasted 20 years. he's now using plastic drums, which he expects will last
a lot longer.
>> >how much insulation is required
>> >to keep them at the supposed design temperature of 130 f?
>
>a better question may be can you actually achieve a temperature above 90 f
>with this set up?
that's a good question. you need to be careful about air leaks and thermal
bridges. high temps are not hard to come by. we saw 154 f in our sunspace
last winter. think about stagnated solar collectors. that's what a solar
closet is, with some thermal mass inside, insulated at night... how hot will
your rooftop solar collector get with just one layer of r1 glazing, if it's
30 f outside, and it's getting 300 btu/hr of sun, and there's no water flow,
and there's noplace else for the heat to go except back out thru the glazing?
ohm's law for heatflow, aka newton's law of cooling, says delta t = u x r,
ie t = 30 f + 300 btu/hr x r1 = 330 f. would you disagree with that, dan?
>> >>also what about radiant floor heat?
>...dont overlook the formidable plumbing problems you will encounter when
>you try to connect a radient loop (which can have no air blockage) with
>55 gal drums.
why do all that? just let some warm air rise up into the house from the
solar closet in the basement... if you want a radiant floor, you can heat
it with hot air from below: insulate the ceiling of the closet, and open
up a motorized damper to let some warm air out of the closet to pool below
the basement ceiling and heat the first floor from below. if the air below
an r1 30 x 30' floor is 80 f, (80-70) 30x30/r1 = 9k btu/hr will flow up
through the floor into the 70 f room, more if the floor is not perfectly
airtight. warm air rises, so if the basement is fairly airtight, the warm
air will stay near the ceiling, vs. heating the whole basement.
>just an aside, i've seen a lot of crap posted lately about roof panels.
me too. for instance, some people say they are economical.
>for the record, in 6 years of installing, maintaining, removing and
>reinstalling roof panels for new shingles, i have never once, never, been
>called back for a roof leak. i have 15 year old installations that are
>just as leak proof as the day they went in.
i'm sure you do better work than many in this field, dan. back in february,
pat hennin from shelter institute told me that for a few years, they were
getting phone calls _every day_ from people who wanted their rooftop panels
removed, for various reasons: water leaks, roof leaks, complicated systems
that had stopped working, with nobody around who knew how to fix them,
aesthetics, selling the house, broken glass, etc. that isn't to say this
can't be done right, just that often, it isn't.
>yes, they are expensive, and may not pay back for 7 to 10 years.
let's see... here's one scenario: you buy one or two new 4 x 8 rooftop
solar water heating panels for $30/ft^2 (?), and pay someone $200 (?) to
install them on the roof with some $50 mounting brackets, and run 40 feet
of $1/foot insulated pipe down to the basement, where there are two $50
pumps and a $50 tank and a $50 heat exhanger and a $150 differential
thermostat and miscellaneous plumbing to connect all this to an existing
water heater, and the 50 watt pumps run 1,500 hours a year, ie 1500 kwh/year,
another $15 worth of electricity, and the whole system lasts forever...
requiring no mantenance, and collects 1,000 btu/ft^2/day of sun every day,
ie 23 million btu/year, equivalent to 180 gallons of oil/year, say $180's
worth? so... we've invested $2560 in this system, to save $165/year, net,
so the simple payback is 15.5 years. not bad, but it seems to me that
there are better places to invest money, and i'm not sure about all these
costs and assumptions. perhaps you have more accurate numbers.
>but quality panels, made of extruded aluminum and good grade copper with
>glass glazings should last at least five times that, maybe much more.
agreed.
>tell me they're not worth the cost after 50 years of replacing your
>polyethelene sheets every 2 or 3 years.
for some people who don't have much money, poly film, or clearer long-life
mylar film is a good way to go. recycling it every 3 years takes about an
hour, if you use the right hardware, ie 16 hours over 50 years. greenhouse
uv poly film costs 5 cents/ft^2, and it's guaranteed for 3 years. with a
piece of shadecloth over it in the summer, it should last longer.
but there are more than two choices. many people might prefer polycarbonate
plastic or glass to polyethylene sunspace glazing, with some sort of bare
water heating panels, eg big fins, inside the sunspace, with no pumps or
heat exchangers, with warm water naturally rising up to a conventional water
heater upstairs that seldom turns on, and the "waste heat" heating the house.
if you can read a book in your sunspace on a sunny winter afternoon, the
economics change...
nick
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