Subject: Re: Let's reconsider solar heating and cooling!

From: [email-masked]
Date: 21 Jul 1995 12:31:50 GMT

Ten years ago, Solar Age magazine published a story about absorbtion cooling
for residential use. The issue is well packed, but I will try to dig it out.
	The house was in Phoenix, outdoor design temp of 105 F. The approx. 2000
sq. ft. house had the southside roof covered with flat panels. The chiller took up a 
large shed next to the house. The only electrical devices were fans, pumps and 
controls, couple hundred watts. The equipment was Japanese.The owner was an
Arizona State engineering professor.
	That's all I can remember of the article.

	Solar cooling needs to start with the custom house and visionairy commercial
developers. Residential construction is usually the last place to see innovation. 

Jim Sullivan

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From: [email-masked] (Will Stewart)
Date: 20 Jul 1995 13:25:24 GMT

>    (1) Is there any value in maintaining the division, "Active" vs.
>        "Passive," which assumes that only one or the other is really OK,
>        and trashes its opposite?

This is simply a way of determining certain system parameters.  If the words
'active' and 'passive' were not used, other words with the same meanings woul
take their place.  Just ignore those who promote division and strife.

>    (2) What's the better use of solar, when indoor life/work/play in hot,
>        humid climates makes refrigerated air conditioning essential for the
>        high productivity of warmblooded animals inside  ---
>           (a) Photovoltaic electricity transformed and stepped up to drive
>               vapor-compression units, or

This can certainly work, though you will need significant storage to run the
A/C after peak solar insolation periods.

>           (b) Thermal energy, stored, concentrated and assisted as needed,
>               driving absorption-cycle units? (water/LithiumBromide, not
>               ammonia!)  

This is also doable, in fact done already in some applications.

The driver at the present time, as I've been told, is cost.

William R. Stewart, Jr	(Will)      "Don't worry, be happy"  - Bobby McFarren
[email-masked]   (703)760-0239

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From: [email-masked] (PAUL KETTLER, 928-4332 , MAIL DROP 5B , MDT CELL)
Date: 21 Jul 1995 15:09:55 GMT

In article <[email-masked]>, [email-masked] (Elaine Gallegos) writes:
>George A. Gleason ([email-masked]) wrote:
>
>
>: Solar: well, when I see the words "active" and "passive" together like that
>: I can't help but think of something vaguely erotic going on; better to drop
>: the distinction since its meaning is diminishing; and, that done, we will
>: probably rid ourselves of a bunch of people whose emotional constitution
>: thrives on dichotomies.
>
>: Item (2), I would think that thermal-based cooling systems are more direct &
>: therefore efficient than going through conversion to electricity.  However,
>: this might be going at it backwards; after all one could do that geothermal
>: cooling thing by drilling a couple of holes in the ground to circulate air
>: through and get it back at 55-degrees F.  Then the solar power could operate
>: the fans which move the air, and that would seem to be more efficient than
>: using the solar power to drive a system which must create a heat
>: differential.  (BTW as you might guess, I'm out of my field here...)
>
>  I think that we need to constentrate on cutting down heat gain in the 
>first place, and consern ourselves with cooling the air down secondarily.
> If the air itself is 90degrees, we only need to cool it down say 10 
>degrees to be reasonably comfortable, and only 15 degrees to be 
>completely comfortable.  No problem for your cooling system to just take 
>it down 15 degrees.
>  Solar heat gain however is like holding a match to one side, and an ice 
>cube to the other.  Your cooling system is going to have to work as hard 
>as it can just to duct away part of the solar heat gain.  You can't even 
>work on cooling the air those few degees it would take to make all the 
>difference in the world.
>  Of course, ideally, we will begin to design out buildings not to have 
>tremendous heat gain in the first place.  We have all had the experience 
>of being out on a blazing hot day, then finding shade under some very 
>dense trees.  Amazingly, we find that it is some 20% cooler under the 
>shade of the trees.  True, trees transpire, and literally cool the air 
>under them, but also what is going on is that in that space under the 
>tree, you're not getting any heat gain.  No complicated electrical 
>cooling system here.
>  What we need to do is to work out methods of reducing heat gain in our 
>present structures.  This is what I have been working on this summer.  I 
>bought some opaque silver tarps, which have been installed over the two 
>walls that are exposed to the sun most during the day.  Covering one room 
>at a time, it seems that the tarps are effective in reducing heat gain.
>  My other big challege will be the roof.  On one end, the ceiling is all 
>open beam.  I have decided to try sprinkers on the roof.  The first 
>attempt was a failure.... insufficient water pressure to for any decent 
>coverage... my coolant ended up all over the ground.  Next, I will 
>purchase some soaker hose and find a way to keep the water on the roof 
>without run off.
>  Another thing that might work is finding a way to stretch a reflective 
>tarp over the top of the house for some dense shade.
>

	Keeping the sun out is very important. I have put foil backed foam
in some windows on the west side . As for tarps I haven't tried It should  
work fine as long as you leave some air gap between the tarp and the surface.

	Sounds like it would be pretty ugly tho.

---

From: "Robert G. Marsh" <[email-masked]>
Date: Fri, 21 Jul 1995 10:02:32 -0400

Hi, as I'm sure everyone here realizes,standard insulation  SLOWS down the 
movement of heat, it does not stop it. One the house I just built in MO, 
as in the last 2 other commercial buildings, I put a double roof on:

Painted galv. steel roofing
purlins
2" spacer running vertically (up and down the slope of the roof)
	this is screened at both the top and bottom, continous opening 
	at both top and bottom, to create a sheet of air moving under the 
	metal roofing to cary away heat, and keep the underside of the metal
	dry (re: condensation).
White rolled roofing (50 yr. warantee for use not exposed to the sun)
plywood
------------    denny paper once, not sure it's needed
2 X 8's on 2' centers with 7.5" fiberglass insulation
vapor barrier
---------------  denny paper   ( perf. foil faced kraft paper)
finished ceiling (tongue and groove or drywall)
4 X 6 rough sawn beams on 4' centers

this was for a cathedral ceiling......
A great construction advantage was building from the bottom up, not 
having to put drywall ( part was drywall) overhead, but placing the 
beams, then the drywall, then the  2x8's etc......

The house is shaded, earth sheltered on the north and 50% of the east and 
west, and has the chases built to hook up earth tubes.....

Feedback on this would be appriciated, but last summer, without the earth 
tubes, consistantly over 100 F outside, this house did hit an 
uncomfortable without a fan 82 F.
Robert

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From: [email-masked] (Elaine Gallegos)
Date: Sat, 22 Jul 1995 18:41:03 GMT

Robert G. Marsh ([email-masked]) wrote:
: Hi, as I'm sure everyone here realizes,standard insulation  SLOWS down the 
: movement of heat, it does not stop it. One the house I just built in MO, 
: as in the last 2 other commercial buildings, I put a double roof on:

: Painted galv. steel roofing
: purlins
: 2" spacer running vertically (up and down the slope of the roof)
: 	this is screened at both the top and bottom, continous opening 
: 	at both top and bottom, to create a sheet of air moving under the 
: 	metal roofing to cary away heat, and keep the underside of the metal
: 	dry (re: condensation).
: White rolled roofing (50 yr. warantee for use not exposed to the sun)
: plywood
: ------------    denny paper once, not sure it's needed
: 2 X 8's on 2' centers with 7.5" fiberglass insulation
: vapor barrier
: ---------------  denny paper   ( perf. foil faced kraft paper)
: finished ceiling (tongue and groove or drywall)
: 4 X 6 rough sawn beams on 4' centers

: this was for a cathedral ceiling......
: A great construction advantage was building from the bottom up, not 
: having to put drywall ( part was drywall) overhead, but placing the 
: beams, then the drywall, then the  2x8's etc......

: The house is shaded, earth sheltered on the north and 50% of the east and 
: west, and has the chases built to hook up earth tubes.....

: Feedback on this would be appriciated, but last summer, without the earth 
: tubes, consistantly over 100 F outside, this house did hit an 
: uncomfortable without a fan 82 F.
: Robert

      82?  the warmest it got was 82 degrees?  without the fan?  My house 
is often 100degrees when it is only 90 outside.  The way my AC sucks up 
energy, I may as well comission my own spillgate at the local dam.

---

From: [email-masked] (Richard Foy)
Date: Sun, 23 Jul 1995 23:03:24 GMT

In article <[email-masked]>,
>energy, I may as well comission my own spillgate at the local dam.

This is a clear demonstration of the ability to lower energy
consumption by sophisitcated efficiency.

I suspect that over the life of the house the total cost the
efficiency house will be much less than an equivalent conventinal one
using ari conditioning to maintain similar comfort levels.

-- 
"No truth will deny its own liberation" --author unknown 

URL ftp://ftp.netcom.com/pub/rf/rfoy/ai.html 
Amnesty International, Richard Foy. Los Angeles CA, USA

---

From: Carroll <[email-masked]>
Date: 24 Jul 1995 15:43:20 GMT

I painted the roof on my shed white using an elastomeric paint, and the 
temp. inside stays pretty cool even with full sun shining on it all day. 
I've read somewhere that white elastomeric will only heat up to about 80f 
(I think from one of the manufactures lit), so inside it stays pretty 
cool with just an air flow from windows to skylights. 

We're building our home right now (40ft dome) and will again use 
elastomeric as the final coating. We've also kept a huge rock in the sun 
room for heating/cooling, plus a stone masonry stove in addition to earth 
tubes. All our windows and skylights are angled for winter sun, so in the 
summer, they don't get any direct light.

Bruce Carroll
Virtual Mountain
Email: [email-masked]

---

From: Richard Austin <[email-masked]>
Date: 24 Jul 1995 15:36:48 GMT

I think the idea of solar air conditioning is too limiting. What about 
night sky refrigeration which uses no sun at all (maybe we should call 
it Moonlight Air Conditioning). Or what about the idea of storing 
winter's coolth for summer cooling of refrigerators and living space. 
The idea of using the sun for cooling seems absurd which the night sky 
is already at absolute zero (or nearly so radiantly speaking). So how 
about using the terms Natural Air Conditioning or Natural Heating?

Other suggestions?

Richard Austin  --  email: [email-masked]  --  radio: KG7SU
-------------------------------------------------------
              Institute for Planetary Renewal
"Creating a Better World Through Healing & Design"

---

From: [email-masked] (Michele Friedrich)
Date: 21 Jul 1995 17:48:14 GMT

>tarp over the top of the house for some dense shade.
Someone at Davis Energy Group (Davis, Ca) came up with a water ballast 
roof which they used on the roof of a post office in Sacramento.  In hot,
dry climates this is a great alternative.  Others are using white, polyvinyl 
or rubber roofing which cuts down on the solar gain and insulates at the
same time.  However, if you live in an area that needs heat more than cool
then you should use black rubber roofing to get more solar radiation and
still insulate

---

From: [email-masked] (Hugh Lippincott)
Date: 26 Jul 1995 16:21:22 GMT

In article <[email-masked]>, [email-masked] (Will Stewart) writes:
|> In article <[email-masked]>, Richard Austin <[email-masked]> says:
|> >
|> >I think the idea of solar air conditioning is too limiting. What about 
|> >night sky refrigeration which uses no sun at all (maybe we should call 
|> >it Moonlight Air Conditioning). 
|> 
|> I've heard of this, were solar collectors that were employed for heat 
|> gain in the winter daytime were used for heat rejection in the summer
|> nights.  I didn't hear how the experiment(s?) went, perhaps others have.
|> I would certainly be interested in hearing any results.

Efficient solar collectors do NOT reject heat at 50-250 F.  That's the
collection temperature.  they should be well insulated and have the right
coating to NOT radiate in that range.

I expect you would have to either have another set of radiators or 
significantly change your collectors. = investment $$$

|> >Or what about the idea of storing 
|> >winter's coolth for summer cooling of refrigerators and living space. 
|> 
|> The issue we're looking into right now is the scale of the storage.
|> It can be done, but can it be done at a reasonable cost?
THAT IS the question.
|> 
|> William R. Stewart, Jr	(Will)      "Don't worry, be happy"  - Bobby McFarren
|> [email-masked]   (703)760-0239

-- 
	Hugh Lippincott 	     x2955	  [email-masked]
	Imaging Systems, SQA,	     M/S 105      Bldg4 2nd floor, Col Q15

---

From: [email-masked] (Michael O'Brien)
Date: Fri, 28 Jul 1995 11:35:01 -0800

How about reconsidering climate-specific heating and cooling? Where I
live, in the Portland/Willamette Valley coastal marine climate, heating
and cooling needs are completely different from the high basin country
that is only about 150 miles away over the Cascades. What works adequately
here, doesn't work over there. So the solutions have to be tailored to the
climate. I would even say that what works for one type of building doesn't
necessarily work on another. For example, night cooling by flushing with
cool outdoor air works great on two-story single family houses, but not
very well on one-level apartments. 

In our energy-efficient home program, Super Good Cents, we concentrate on
maximizing the heating and cooling benefits from architectural and
construction features that are already in the building. For example, code
requires a certain amount of structural ventilation in attics, so every
house has eave vents and roof jacks. For literally a few dollars more, the
code vents can be upgraded to continuous eave and ridge vents, giving
better moisture protection and some cooling benefit. We can go a long way
towards keeping the building comfortable with such measures. Some places,
like Sacramento, have utility- and city-sponsored programs to upgrade
street trees and landscape trees to large shade trees that are wonderful
for cooling. A $200 tree can provide the cooling equivalent of over a ton
of air conditioning, for free.

Personally, I like low-tech solutions that are practical and affordable.
In my experience, people just won't give up their chandeliers and
fireplaces for solar gizmos, but they will spend a few bucks for something
that has an apparent benefit.

Just my $.02, Mike

-- 
Mike

---

From: [email-masked] (Michele Friedrich)
Date: 27 Jul 1995 18:26:41 GMT

>|> I would certainly be interested in hearing any results.

Two years ago as a school project, I looked into this technology.  It ends up that
there are new emissivity coatings being developed that switch (electrically) the solar 
absorber cover (glass/plastic)) in order to change which wavelengths that will 
go through the material.  Lawrence Berkeley Lab (LBL) has developed some 
of these coatings for window panes and using them in solar collectors was 
tested years ago.  I would have to dig into school notes to find the references
but I don't remember it being difficult to find articles on night sky radiation cooling.
>significantly change your collectors. = investment $$$

The coatings are not cheap and the economic analysis I did at the time to 
cool using night sky radiation was not very favorable even out here in the
desert where we have lots of clear nights 

Michele Friedrich
[email-masked]

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From: [email-masked] (George A. Gleason)
Date: 29 Jul 1995 09:25:44 GMT

Test message, ignore...

---

From: "Charles E. Reese" <[email-masked]>
Date: 28 Jul 1995 15:40:55 GMT

[email-masked] (Will Stewart) wrote:
>
> In article <[email-masked]>, Richard Austin <[email-masked]> says:
> >
> >it Moonlight Air Conditioning). 
> 
> I've heard of this, were solar collectors that were employed for heat 
> gain in the winter daytime were used for heat rejection in the summer
> nights.  I didn't hear how the experiment(s?) went, perhaps others have.
> I would certainly be interested in hearing any results.
> 
> >Or what about the idea of storing 
> The issue we're looking into right now is the scale of the storage.
> It can be done, but can it be done at a reasonable cost?
> 

Have you considered underground storage in static aquafers?  The idea is to
have two wells, in the summer pump solar heated water into the deeper well
and pump cold water out of the upper well.  In the winter you reverse the
flow recovering your hot water for heating and storing cold water for the
next summer.  If the water table is reasonably high then you almost don't
need a pump in the winter.  I have seen where large quantities of summer heated
water is stored in old mines in Sweden for use as winter heat.

---

From: Gary Cunningham <[email-masked]>
Date: 30 Jul 1995 21:21:46 GMT

[email-masked] (Will Stewart) wrote:
What about Geothermal.  It is already here, it uses the earth to cool and heat coolant (water).  We use it in Texas.

---

From: [email-masked] (Michael O'Brien)
Date: Mon, 31 Jul 1995 15:41:59 -0800

In article <[email-masked]>, Gary Cunningham
<[email-masked]> wrote:

> What about Geothermal.  It is already here, it uses the earth to cool
and heat coolant (water).  We use it in Texas.

Geothermal (Water Furnace, Florida, and similar) works very well here in
Oregon, for space heating, cooling and water heating, but it is expensive.
Costs anywhere from $10,000 to $15,000 for one house. Is it cheaper in
Texas?

-- 
Mike

---

From: [email-masked] (Will Stewart)
Date: 31 Jul 1995 14:56:40 GMT

In article <[email-masked]>, [email-masked] (Michael O'Brien) says:

>
>In our energy-efficient home program, Super Good Cents,

I'd like to find out more about this, please email me an overview.

>Some places,

I am finding that planning to have PVs on the roof is preventing me from 
taking this route.  Though the design does provide eaves designed to block 
direct solar window gain in the summer, other solar loads still remain.
Of course, if the net electrical consumption is less with shade trees, then
a rethinking of my energy management plan is in order.  

>that has an apparent benefit.

Actually, I am giving up the chandeliers (but keeping the fireplace hearth for
backup heat) for solar gizmos (passive heat, active hot water, PVs, high 
efficiency appliances).  My solar engineering coursework along with my perception
of future energy directions has motivated me to reconsider the usual architectural
and interior approaches.

Regards,

---

From: [email-masked] (Will Stewart)
Date: 31 Jul 1995 14:43:14 GMT

>water is stored in old mines in Sweden for use as winter heat.

Do you have any references, findings, or POCs for these projects?  I would very much
like to find out more, especially lessons learned, empirical data, suitable ground
conditions, etc.

Thanks,

---

From: [email-masked] (George A. Gleason)
Date: 2 Aug 1995 07:09:02 GMT

Hope this isn't offtopic, but does anyone have information on whether
equipment and materials for blown-insulation are available for use by fairly
competant do-it-yourselfers?  A group of us are doing some eco retrofits on
a house in Berkeley which is part of an organisation with ecological and
community-related goals.  We have fairly good construction skills among us;
the work will begin in September.  Feel free to email, [email-masked]
Thanks...

---

From: "Charles E. Reese" <[email-masked]>
Date: 1 Aug 1995 18:00:22 GMT

> [email-masked]   (703)760-0239

Sorry, I think I saw the thing about Sweden on a 'Beyond 2000' or some such program.  I had 
the idea about aquafer storage several years ago and I haven't seen anything published on
it.  I tried a Lycos and WWWW serach but didn't get any hits.
Who knows you might be the first one to do it!!

Charlie Reese

---

From: [email-masked] (George A. Gleason)
Date: 3 Aug 1995 09:08:13 GMT

Interesting!  Now personally I prefer to support locally owned businesses
that pay their workers an honorable wage, rather than the large chains, but
I'm willing to bet that some of the local building-supply places in Berkeley
or Oakland have picked up the idea if nothing else to stay competitive.  If
they haven't, then I'll certainly write a friendly note to management
suggesting it would be a good idea and see what happens.

-george

---

From: Gary Cunningham <[email-masked]>
Date: 2 Aug 1995 22:51:40 GMT

[email-masked] (George A. Gleason) wrote:
> Ref ...
> equipment and materials for blown-insulation 

Yea, 
Go to home depot,  they rent free equip if you by the insulation
>from  them.

GMC

---

From: Dennis Shinn <[email-masked]>
Date: Thu, 3 Aug 1995 21:50:48 -0700

> and heat coolant (water).  We use it in Texas. 

Have any of these projects been published and if so, could you direct me 
to which pubications.

Thanks in advance for the information.

Dennis Shinn / [email-masked]
SAUG-BBS [206] 644-7115 
The Professional CAD & Graphics Network PCGNet 9:517/215

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From: [email-masked] (Russel A. Hill)
Date: 3 Aug 1995 16:14:30 GMT

> uncomfortable without a fan 82 F.

I'd like to know how this house did in the winter.  Did the roof design 
have any significant effect (+/-) of heating cost?

Russel A. Hill

BTW: Are there any references to solar 'refrigeration'.  I don't mean 
cooling a house but rather running a refrigerator for food storage using 
something like the heat engine used in gas appliances except the heat 
source would be solar.  How large a heat sink would be required to get 
through the night? ...an overcast day?  How large a collector would be 
required to gather the necessary heat?

---

From: [email-masked] (John MacDonald)
Date: 4 Aug 1995 18:56:12 GMT

>Costs anywhere from $10,000 to $15,000 for one house. Is it cheaper in

In Halifax, one of the office buildings on the waterfront uses water from
the harbour in a heat pump fashion.

***********************************************
... and crawling on the planet's face
	some insects called the human race...
... lost in time ... lost in space
... and meaning
***********************************************

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From: Robert Gordon Marsh II <[email-masked]>
Date: Sat, 5 Aug 1995 20:51:27 -0400

well.... in the first winter (lots of walls with no insulation), if we 
had sun, we had windows open. This last winter, from the report I 
received from the renters, they burned about 1/3 cord of wood, until late 
in Febuary, and then used about a full cord of wood for the rest of the 
season. (lost the sun, overhang designed to pick up the sun in the fall 
when you need heat, and it therefore loses it too soon in the spring). 
Some of the heat from the stove is direct, the rest is used to heat water 
that circulates through the floors:

------	Ceramic tile
XXXXXX	2.5" concrete slab, with entran tubing 12" spacing
WWWWWW	1" pink board
QQQQQQ
QQQQQQ	8" gravel
QQQQQQ

With the high ceilings, if the floor was not warm, I'm sure it would feel 
cool, the renters thought it was the most comfortable house they have 
lived in.......
	Robert