Enertia Building Systems passive solar houses
Kirk G. Bobash
houses?
We're looking in to possibly building one in central New Jersey, and we're
wondering how good they really work at keeping the house warm in the winter
and cool in the summer. Also just any comments on how much people like to
live in these houses in general. Also any problems they had in building it,
etc.
Ol' Northwest
Kirk;
Just took a look at some Enertia pages, and bookmarked it. The theory
sounds excellent, and I can vouch for the "enertia" of solid wood. I
built a solid log cabin on a lake in Ontario, no insulation in the
ordinary sense in the walls. Once that place gets warmed up, it holds
heat all night, no hopping up to rebuild the fire. (Roughly 27 degrees
F last weekend.) In the summer, we open windows at night, close 'em in
the morning... and in an 85 degree F day, it's like walking into a cool
cave.
I might examine how the Enertia system would adapt to logs...
Cheers,
Nelson
Thomas G. Baker
80s?
R. Gary Boyd of Charleston designed one which still stands, although the
present owner is uninterested in the passive solar aspects of the house.
TB
Steve Spence wrote:
> IIRC it's an envelope type system. double wall system with air gap between.
> have built similar type system, concept works.
>
> --
>
> Steve Spence
> Subscribe to the Renewable Energy Newsletter:
> http://www.webconx.com/subscribe.htm
>
> Renewable Energy Pages - http://www.webconx.com
> Palm Pilot Pages - http://www.webconx.com/palm
> X10 Home Automation - http://www.webconx.com/x10
> ssp...@webconx.com
> (212) 894-3704 x3154 - voicemail/fax
> We do not inherit the earth from our ancestors,
> we borrow it from our children.
> --
>
> "Kirk G. Bobash" <k...@jerseycow.com> wrote in message
> news:%ZtU5.3$3B3.134@client...
Steve Spence
Nick Pine
>IIRC it's an envelope type system. double wall system with air gap between.
>have built similar type system, concept works.
No. Bad news, especially with no insulation. It only works when the
outdoor temp is more than 70 F during the day and less at night...
Nick
Article: 4143 of alt.energy.renewable
From: ni...@vu-vlsi.ee.vill.edu (Nick Pine)
Newsgroups: alt.energy.renewable
Subject: Re: narrow minded nerds
Date: 3 Feb 1995 09:21:32 -0500
Organization: Villanova University
<big...@ins.infonet.net> wrote:
Robert Winfield <winf...@CPCUG.ORG> writes:
>>> >...Hundreds of articles have appeared in newspapers, books and magazines
>>> >from October 78 to April 1981...
>>>
>>...you are practically calling mr butler a liar...
>
>If the claims hold water...then we'll talk.
There are two articles in Rodale's New Shelter magazine, of September, 1980,
which says "Hard data on double-shell homes" on the cover.
The first article is "Double Shell Houses," subtitled "Finally, some facts,"
on pp 72-82, in which Larry Stains says:
A promotional brochure for Ekose'a, a San Francisco firm that sells double
shell house plans, says its homes "prove it is practical to design and build
a structure which maintains any desired range of temperatures through any
range of climatic conditions at any place on the earth [above the arctic
circle in wintertime, with no sun at all for 6 months? --Nick] without the
necessity of mechanical, electrical or fossil fuel back-up systems."
That's a mighty big claim...
Last winter, two double shell houses were monitored by researchers.
Their findings indicate:
1) The houses _did_ depend on auxiliary heat; thus the design is not
a guarantee of energy self-sufficiency.
2) No way does the earth underneath the house store the majority of
the solar heat collected in the greenhouse.
Don't misunderstand. Double shell houses are good houses that use a fraction
of the energy consumed by conventional designs. But the double shell design
should be understood for what it is, not for what it is cracked up to be.
So, for the facts, let's examine two homes...
A detailed record of temperatures in the Burns house from mid-October to
early February was compiled... then studied by three Boston-area solar
engineers... The monitoring equipment consisted of temperature sensors
at some 30 points throughout the house, and a data logger to keep track
of it all. The findings are revealing. For one thing, temperatures in the
living room sometimes fluctuated from the mid 70s on a sunny afternoon to
the mid 50s by dawn, when it was 0 F outside...
Another double shell given close scrutiny last winter was Robert and
Elizabeth Mastin's house in Middletown, Rhode Island... Last January
the house was monitored for 12 days by scientists from Brookhaven
National Laboratory. To find out how much heat the house required to
stay warm, the scientists installed three 1500-watt heaters in the
house, one on each floor. They were controlled by a thermostat which
the Mastins were requested to keep at 65 F. Daily records tabulated
the electricity used by the heaters. In addition, sensors kept
round-the-clock track of household temperatures. Let's look at one
of the 12 monitored days: January 18. It was overcast; the outside
temperatures ranged from 30 F, at 12:01 a. m. to 41 F at 2 p. m.,
and back down to 37 F by midnight. The Brookhaven equipment showed
that the average "inner house" temperature stayed between 62 and 65 F.
It also showed that the three heaters were tapped for 193,707 Btus
of back-up heat that day. That's the same as burning two gallons of oil.
On a fairly mild winter's day, no less.
The figures for the Burns and Mastin houses help to settle part of the
controversy about double shell homes. But details need to be hammered out...
Everyone has his pet theory, and one double shell aficionado in California
actually talks of "holism" and "loopiness" when explaining the design.
[Gee, I wonder who that was...]
There is a side-box that describes complete working drawings for a series
of double shell houses, sold by Tom Smith and his partner, John Hofacre,
for less than $100. The sidebox also says:
Ekose'a sells blueprints for $500, a semi-custom design service for
$4,000, and a full custom design service for 15% of construction costs.
In order to get plans, you must purchase their $25 book.
The second article is an interview with the same Tom Smith, "The Double Shell:
An owner's Perspective," beginning on page 82. He says, inter alia:
Avoiding confusion about the "envelope" requires only a little deprogramming
from the Higher Order of Convective Loopers. The solar function of the house
is only part of the story, and _there is no significant storage of excess
heat for use during the heat losing times of the day_." [his emphasis]
When asked, "What's the future of the "envelope" system?" (in 1980), he said:
I do not forsee any of the systems we now have surviving past the next few
years. We have created a bit of a Frankenstein with my house here because it
launched the field of envelope homes and is seen in competition with other
systems. Nothing could have been further from my intentions...
I would feel most proud if my house is remembered for being a step in the
evolution toward mass energy-efficient design, rather than for introducing
the "most efficient system."
[Curious how Tom Smith says "my house," not "Lee's house."]
After working on, literally, hundreds of passive designs, and living in
this house over the past three years, I am convinced that energy efficiency
will become considerably less exotic in the future. It is my belief that
if we just study closely what is going on inside a house, we'll come up with
some very simple, if prosaic, solutions. If you have ever spent any time
living in other parts of the world you'd realize that a lot of our energy
problems stem from just plain doing it wrong. It's a snap to save energy
in this country. As soon as more people become involved in the basic math
of heat transfer and get a gut-level, as well as intellectual, grasp on
how a house works, solution after solution will appear.
Amen.
Nick
Pierre Bonnard
Must be more effiscient now with new materials and new products to replace the
air !
Again .. the Ancient were more in advance than moderns !
*****************
Pierre BONNARD pierre...@online.fr
http://pierrebonnard.online.fr/index.htm
A part of MORVAN in France for sabots, handicrafts and wood works
Where to find informations and help on Generic Cadd, Visual Cadd
*****************
Steve Spence a écrit :
Kirk G. Bobash
Glad to hear that you've been warm in your log cabin. I've heard just the
opposite in anecdotal evidence from a friend of a friend (not always the
best source of info!). Of course a lot probably depends on how the house was
built, and the house site (protection from winds, etc.).
Thanks,
Kirk
Ol' Northwest <ngietz...@mts.net> wrote in message
news:3A23B5...@mts.net...
> Kirk G. Bobash wrote:
> >
> > Does anyone out there own one of the Enertia Building System passive
solar
> > houses?
> >
> > We're looking in to possibly building one in central New Jersey, and
we're
> > wondering how good they really work at keeping the house warm in the
winter
> > and cool in the summer. Also just any comments on how much people like
to
> > live in these houses in general. Also any problems they had in building
it,
> > etc.
>
georges
>Nelson,
>
>Glad to hear that you've been warm in your log cabin.
I believe he's warm because he's taken the time and energy
to heat up those log walls. The thremal capacity is large ( Nick jump in:)
compared to the sheetrock in a stick house.
--georges
Nick Pine
>I believe he's warm because he's taken the time and energy
>to heat up those log walls. The thremal capacity is large ( Nick jump in:)
>compared to the sheetrock in a stick house.
Yeah. A house may hold heat for a long time even tho it takes a few
cords of wood to warm it up. High thremal capacity (C) often goes with
low resistivity (R). The product (RC) matters for cooling. As I recall,
wood has about R1 per inch of thickness (the chinking and thin parts
of a log lose most of the heat) and half the specific heat of water,
ie 0.5 Btu/lb-F.
Nick
kgb
Nick Pine <ni...@ufo.ee.vill.edu> wrote in message
news:9041de$q...@ufo.ee.vill.edu...
Help me out here Nick with these calculations you're presenting above, as
I'm a newby to all of these solar calculations. Considering the design
specs for one of these Enertia homes, can you answer the following:
* So if the walls are made with 6x6 lumber, the wall will be 6" thick. The
lumber is stacked on top of each other with no chinking (a groove is precut
in the top/bottom of the lumber into which a spline is placed and some
rubber gaskets), you probably get about R6 out of the wall itself, no?
* The part about the water confuses me a bit. Are you saying that wood has
a thermal capacity of about half that of water?
* Also, if the sun is doing a good part of heating up the wood in the walls
(and the slab in the basement), how well will the wood hold the heat? (also
remembering the double walls in the south and north parts of the house)
-- kgb
kgb
The articles that you have supplied below are from 1980. That seems like a
pretty long time ago in solar technology terms. Have you seen any newer
articles, studies, etc. since then? I think that the Enertia concept may
have been conceived of after 1980, I'm not sure from their web site. The
earliest mention of one of their homes being built that I saw was in 1985.
Thanks,
kgb
Nick Pine <ni...@ufo.ee.vill.edu> wrote in message
news:902dan$q...@ufo.ee.vill.edu...
Nick Pine
>...if the walls are made with 6x6 lumber, the wall will be 6" thick. The
>lumber is stacked on top of each other with no chinking (a groove is precut
>in the top/bottom of the lumber into which a spline is placed and some
>rubber gaskets), you probably get about R6 out of the wall itself, no?
Maybe more. Depends on the wood and the density and the moisture content.
Table 4 on page 22.9 of the 1993 ASHRAE HOF says Hem-Fir with 12% moisture
and 24.5-31.4 lb/ft^3 has US R1.11 to R1.35 per inch across the grain, ie
R6.7 to R8.1 for a solid 6" wall. Pine has R0.9 to R1 per inch. Oak has
R0.8 to R0.9. Conductivity is proportional to density, ie denser woods
have lower R-values.
>* The part about the water confuses me a bit. Are you saying that wood has
>a thermal capacity of about half that of water?
Yes, by weight. The HOF lists all these woods as having a specific heat of
0.39 Btu/lb-F, 39% that of water. So a 28 pound cubic foot of Hem Fir has
0.39x28 = 10.9 Btu/F of thermal capacitance, compared to 28 Btu/F for
28 pounds of water or 64 Btu/F for a cubic foot of water.
>* Also, if the sun is doing a good part of heating up the wood in the walls
>(and the slab in the basement), how well will the wood hold the heat?
Miserably, in my opinion. An average 1000 Btu/ft^2 of sun falls on
a south wall on an average 30 F January day where I live near Phila.
An 8' R6 cube with an R2 double-glazed south wall with 80% solar
transmission and 5x64ft^2/R6+64ft^2/R2 = 85 Btu/F of conductance would
only have a temperature of 30+0.8x64x1000/(24hx85) = 55 F inside,
even if it contained an infinite thermal mass.
The wood stores C = 5x64ft^2x0.5ftx28Btu/F-ft^3 = 4480 Btu/F, like 10
55 gallon water drums. We might think of that thermal mass as being in
the center of the wall, with a temperature halfway between the inside and
the outside on an average day, ie (30+55)/2 = 42.5 F. On a cloudy day,
it loses heat from the inside surface to the outdoors through the R2
south window via half the wall's R-value and from the outside surface
to the outdoors via half the wall's R-value, so we have an equivalent
circuit like this (in Courier font):
R2/64ft^2 R3/(5x64ft^2) R3/(5x64ft^2)
30 F -----www----------www-----*-----www----- 30 F
window <----- |
I --- 4480 Btu/F
---
|
_
RC = 0.00762F-h/Btux4480Btu/F = 34 hours, so after 1 cloudy day, the wood
capacitor temperature drops to 30+(42.5-30)exp(-24/34) = 36.2 F, with the
capacitor losing I = (36.2-30)/0.0406 = 153 Btu/h from the inside to the
outdoors via the window, making the room temp 30+153R2/64 = 34.8 F.
Adding another cube inside or a basement slab doesn't help much.
Hype apparently helps a lot :-)
Nick
Nick Pine
>The articles that you have supplied below are from 1980. That seems like a
>pretty long time ago in solar technology terms. Have you seen any newer
>articles, studies, etc. since then?
No.
>I think that the Enertia concept may have been conceived of after 1980,
>I'm not sure from their web site. The earliest mention of one of their
>homes being built that I saw was in 1985.
Better never than late? :-)
Nick
Steve Spence
and groove with foam and caulking between layers.
--
Steve Spence
Subscribe to the Renewable Energy Newsletter:
http://www.webconx.com/subscribe.htm
Renewable Energy Pages - http://www.webconx.com
Palm Pilot Pages - http://www.webconx.com/palm
X10 Home Automation - http://www.webconx.com/x10
ssp...@webconx.com
(212) 894-3704 x3154 - voicemail/fax
We do not inherit the earth from our ancestors,
we borrow it from our children.
--
"Nick Pine" <ni...@ufo.ee.vill.edu> wrote in message
Steve Spence
life. warm and toasty all winter, even when -40 outside. less airflow than
stick built. 12" logs do have thermal mass. better than 2x6 with pink
insulation.
--
Steve Spence
Subscribe to the Renewable Energy Newsletter:
http://www.webconx.com/subscribe.htm
Renewable Energy Pages - http://www.webconx.com
Palm Pilot Pages - http://www.webconx.com/palm
X10 Home Automation - http://www.webconx.com/x10
ssp...@webconx.com
(212) 894-3704 x3154 - voicemail/fax
We do not inherit the earth from our ancestors,
we borrow it from our children.
--
"Nick Pine" <ni...@ufo.ee.vill.edu> wrote in message
news:905kpn$q...@ufo.ee.vill.edu...
Nick Pine
>Have to disagree on this one nick. I have lived in log homes most of my
>life. warm and toasty all winter, even when -40 outside.
But probably not solar-heated :-)
>less airflow than stick built. 12" logs do have thermal mass...
Sure. Say 1000 Btu/ft^2 of sun falls on a south wall on an average 30 F day,
and your 8' R12 cube with an R2 glazed south wall with 80% transmission and
5x64ft^2/R12+64ft^2/R2 = 59 Btu/F of conductance is 30+0.8x64x1000/(24hx59)
= 67 F inside...
Say the wood stores C = 5x64ft^2x1ftx28Btu/F-ft^3 = 8960 Btu/F, like 20
55 gallon water drums. Suppose that mass is in the center of the wall,
and (30+67)/2 = 48.7 F on an average day. On a cloudy day, it loses heat
from the inside surface to the outdoors through the R2 south window via
half the wall's R-value and from the outside surface to the outdoors via
half the wall's R-value, so we have an equivalent circuit like this
(in Courier font):
R2/64ft^2 R6/(5x64ft^2) R6/(5x64ft^2)
30 F -----www----------www-----*-----www----- 30 F
window <----- |
I --- 8960 Btu/F
---
|
_
RC = 0.01364F-h/Btux8960Btu/F = 122 hours, so after 1 cloudy day, the wood
cap drops to 30+(48.7-30)exp(-24/122) = 45.4 F, losing I = (45.4-30)/0.05
= 308 Btu/h from the inside to the outdoors via the window, making the room
30+308R2/64 = 39.6 F. After N cloudy days with no woodstove, the room temp
becomes 30+11.7exp(-24N/122), 37.9 after 2 days, 36.5 after 3, 35.3 after 4,
and a warm and toasty 34.4 after 5...
Nick
dw
Anthony Matonak
Well, I don't know about that. I've heard that in some countries stables
were designed as the ground floor of buildings so that the heat from
the animals (and I suppose decomposing matter) would rise to the floors
above. In the blurb quoted they don't mention anything about biological
heating systems. I've even heard that spontaneous combustion is a product
of biological activity in oil soaked rags and the like. If bacteria can
generate enough heat to spark off a fire I'm sure you could design something
using them to heat a home with. Yes, it's still a furnace and it'll still
need a fuel but the kind of fuel it takes might be something you're throwing
away now. For that matter, biofuels of any sort aren't 'fossil' fuels so any
oil furnace using vegetable oil should qualify as well.
Anthony
Sylvan Butler
>heating systems. I've even heard that spontaneous combustion is a product
>of biological activity in oil soaked rags and the like. If bacteria can
>generate enough heat to spark off a fire I'm sure you could design something
Nah, last I heard that was not bacteria, that was a chemical reaction.
The "drying oils" such as linseed oil (not all oils are drying oils)
react to air by polymerizing (forming longer hydrocarbon chains). This
produces heat. Too much heat and you get a fire. And since the oil is
flammable, as typically are the rags it is saturating, the odds
increase that you will get a fire.
sdb
--
More guns means less crime. ISBN:0-226-49363-6
***
Watch out for munged e-mail address.
User should be sylvandb1 and host is at bigfoot.com
Do NOT send me unsolicited commercial e-mail (UCE)!
vha...@cc.helsinki.fi
Sylvan Butler <ZsylvanDB...@Zhotmail.Zcom.invalid> wrote:
>On Sat, 09 Dec 2000 23:16:52 GMT, Anthony Matonak <res0...@gte.net> wrote:
>>heating systems. I've even heard that spontaneous combustion is a product
>>of biological activity in oil soaked rags and the like. If bacteria can
>>generate enough heat to spark off a fire I'm sure you could design something
>
>Nah, last I heard that was not bacteria, that was a chemical reaction.
>The "drying oils" such as linseed oil (not all oils are drying oils)
>react to air by polymerizing (forming longer hydrocarbon chains). This
>produces heat. Too much heat and you get a fire. And since the oil is
>flammable, as typically are the rags it is saturating, the odds
>increase that you will get a fire.
A compost heap generates heat and even a small thermally insulated
compost will keep on working in any climate.
Cattle farms have enough dung to get more than enough methane gas,
they don't need any additional energy.
A normal household cannot do it.
VesA
James Stahl
heating and storage of that heat (energy) until needed. Hence the gains made
throughout a sunny day in the design would be absorbed and radiated that
eve. It takes full advantage of a double layer air gap form exterior to
interior. Conduction currents constantly moving around interior envelope.
The other key is the specific heat of the solid wood structure, floor
product in the sun area. The ability to absorb radiant energy form the sun
and transmit it back as the surrounding masses radiant less energy. Also the
below surface or basement area is a constant reservoir of 50 deg F. And when
you think that the barrier from exterior and interior is broken with an air
gap your effective heat loss on the interior is reduced significantly. A
personal biosphere. I like the concept and ironically just began reading of
it a few days ago. Very interesting. Go to www.enertia.com and check out the
facts.
"dw" <wes...@pacbell.net> wrote in message
news:3A325951...@pacbell.net...
dw
cost effective as many, however the sale pitch is out of
this world.
Have looked at the site and considered some of the elements
for a house that is under construction.
dw
> "any desired range of temperatures through any range of
> climatic conditions at any place on the earth"
Nick Pine
>I agree that the enertia systems are very good...
Good bullshit :-)
Nick
malcolm.scott
the ground under the house. This will be conducted away through the ground.
It will not be available for the evening. You can't use 50 deg F ground temp
to heat the house without a heat pump.
To retain heat under the house you need a store, insulated from the ground.
The air gap between inside and outside needs to be very narrow to prevent
losses by convection. Something like 16mm max. Anything wider needs to be
filled with a material to prevent air movement such as foam insulation.
Malcolm
"James Stahl" <jst...@statecollege.com> wrote in message
news:WZaZ5.12391$XY.3...@newsfeed.slurp.net...
dw
"normal" home. Not at all cost effective.
Still can't believe anything when the claims are so wild.
James Stahl
utilized. Such as tile, concrete ...etc. The 50 degree basement level is
just an area with minimal loss and more of a cooling source for the summer
phase. If one understands specific heat of masses and heat transfer one can
only then begin to understand the design of this structure. Also I am very
skeptical on the heating cycle in regards to incorporating some in floor
radiant strategy for my own sense of comfort. Other than that the cost of
this strategy is comparable without incorporating other systems and holds
merit for future considerations. And I am not certain what industry Nick is
in but obviously not thermodynamics.
"malcolm.scott" <malcol...@ntlworld.com> wrote in message
news:2TmZ5.7023$ma1.1...@news2-win.server.ntlworld.com...
Nick Pine
>They remind be a building a green house over the top of a
>"normal" home. Not at all cost effective.
At $1/ft^2, that might be cost-effective compared to a normal attic
and roof, especially with a concrete floor and a bubblewall ceiling.
Nick
Nick Pine
>The solar gains will be stored in the wood structure and heat sink devices
>utilized. Such as tile, concrete ...etc.
Got any numbers?
>...If one understands specific heat of masses and heat transfer one can
>only then begin to understand the design of this structure.
Agreed :-)
>I am not certain what industry Nick is in but obviously not thermodynamics.
I'm just an engineer.
Nick
Nicholson L. Pine System design and consulting
Pine Associates, Ltd. (610) 489-1475/0545
821 Collegeville Road Fax: (610) 489-7057
Collegeville, PA 19426 Email: ni...@ece.vill.edu
Computer simulation and modeling. High performance, low cost, solar heating
and cogeneration system design. BSEE, MSEE. Senior Member, IEEE. Registered
US Patent Agent. Web site: http://www.ece.vill.edu/~nick
John
where it can reach 100 deg F. Without exceptional passive ventilation it is not
going to work.
Marie Michael Gabriel
residences. Can you supply URLs?
Thanks, mmg
--
http://www.marmsweb.com/mwdirect.html Eclectic Site
http://www.sgilbertcompaniesinc.com Heavy Equipment Lease
and Finance
http://billfulcher.com Tax, Securities & Insurance/Texas
Steve Spence
of winter on sunny days, and the house is heated with wood/oil combo
baseboard hot water heat. no complaints. well insulated ceiling (single
story, with basement), no airflow between logs (double tongue and groove,
with caulking and foam strip). House is 15 years old, and performs well.
--
Steve Spence
Subscribe to the Renewable Energy Newsletter:
http://www.webconx.com/subscribe.htm
Renewable Energy Pages - http://www.webconx.com
Palm Pilot Pages - http://www.webconx.com/palm
X10 Home Automation - http://www.webconx.com/x10
ssp...@webconx.com
(212) 894-3704 x3154 - voicemail/fax
We do not inherit the earth from our ancestors,
we borrow it from our children.
--
"Nick Pine" <ni...@ufo.ee.vill.edu> wrote in message
news:90ar78$r...@ufo.ee.vill.edu...
> Steve Spence <ssp...@webconx.com> wrote:
>
> >Have to disagree on this one nick. I have lived in log homes most of my
> >life. warm and toasty all winter, even when -40 outside.
>
> But probably not solar-heated :-)
>
> >less airflow than stick built. 12" logs do have thermal mass...
>
> Sure. Say 1000 Btu/ft^2 of sun falls on a south wall on an average 30 F
day,
> and your 8' R12 cube with an R2 glazed south wall with 80% transmission
and
> 5x64ft^2/R12+64ft^2/R2 = 59 Btu/F of conductance is
30+0.8x64x1000/(24hx59)
> = 67 F inside...
>
> Say the wood stores C = 5x64ft^2x1ftx28Btu/F-ft^3 = 8960 Btu/F, like 20
> 55 gallon water drums. Suppose that mass is in the center of the wall,
> and (30+67)/2 = 48.7 F on an average day. On a cloudy day, it loses heat
> from the inside surface to the outdoors through the R2 south window via
> half the wall's R-value and from the outside surface to the outdoors via
> half the wall's R-value, so we have an equivalent circuit like this
> (in Courier font):
>
> R2/64ft^2 R6/(5x64ft^2) R6/(5x64ft^2)
> 30 F -----www----------www-----*-----www----- 30 F
> window <----- |
> I --- 8960 Btu/F
> ---
> |
> _
>
> RC = 0.01364F-h/Btux8960Btu/F = 122 hours, so after 1 cloudy day, the wood
> cap drops to 30+(48.7-30)exp(-24/122) = 45.4 F, losing I = (45.4-30)/0.05
> = 308 Btu/h from the inside to the outdoors via the window, making the
room
Steve Spence
--
Steve Spence
Subscribe to the Renewable Energy Newsletter:
http://www.webconx.com/subscribe.htm
Renewable Energy Pages - http://www.webconx.com
Palm Pilot Pages - http://www.webconx.com/palm
X10 Home Automation - http://www.webconx.com/x10
ssp...@webconx.com
(212) 894-3704 x3154 - voicemail/fax
We do not inherit the earth from our ancestors,
we borrow it from our children.
--
"Nick Pine" <ni...@acadia.ee.vill.edu> wrote in message
news:9161ii$s...@acadia.ee.vill.edu...