Subject: Re: looking suggestions dream house design

From: [email-masked] (Nick Pine)
Date: 25 May 1996 16:01:15 -0400

William R Stewart  <[email-masked]> wrote:
>Peipp wrote:
>> I'm planning to build my dream house this summer and fall...
>> I live in N.E. Oklahoma( 45 mi N.E. of Tulsa)...
>> After seeing all the posts concerning solar rooms and closets I'm now
>> wondering if I could get by without backup heat...

>Where would you put 30 55-gallon drums?

How about a walkout basement, since heat rises? The drums might be 2 deep
and 2 high in a 4' wide x 8' tall x 8' long insulated room. 

>How much insulation is required to keep them at the supposed design
>temperature of 130 F?

Let's see... We'd need an R-value such that

      Ein = 1210 Btu/hr x .8 xmsn x 64ft^2 = 61,952 Btu/day 
	  = 6 hr (130-80)64/R1    south wall, day
	  +18 hr (130-35)64/R     south wall, night
	  +24 hr (130-70)128/R    other walls, 24 hours
          = 19,200+(109,440+184,320)/R = 19,200 + 293,760/R, ie

   42,752 = 293,760/R, or R = 6.87, eg 1" of styrofoam or 2" of fiberglass.

>If they are in the basement, you will have to have a blower running...

Why use a blower, vs a $60 Grainger 36 watt 560 cfm fan that runs when the
sun is shining, with the closet static pressure being 0.05" H20 as measured?
With more care, natural convection would work. 

>and will likely have to have a blower for distribution as well...

How about a 2 Watt $50 Honeywell actuator that opens a damper automatically,
using a $15 Grainger house thermostat to let some warm air rise up into the
house, as required.

>unless you plan to run up and down stairs to adjust a natural convection vent.

Why do that? Another option is an automatic foundation vent such as Leslie-
Locke's FV1-B, with a bimetallic spring that opens some louvers when the
house gets cool, which you can buy at Home Depot for $11.83.

>> What keeps the heat from leaking out of the thermal mass
>> on cloudy days and at night? 
>
>My understanding is there is huge amounts of insulation around the
>55-gallon drums and ducting to them.

That huge inch of Styrofoam? :-)
 
Cheers,

Nick

---

From: [email-masked] (Mike Baum)
Date: Sun, 26 May 1996 17:03:21 GMT

[email-masked] (Nick Pine) wrote:

...snip

>How about a walkout basement, since heat rises? The drums might be 2 deep ...snip again

Not to nitpick but since the nature of heat seems rather basic to this
group I question the reference to "heat rising".   Correct me if I am
wrong, but doesn't heat move without regard to up or down. A more
accurate description might be "hot air rises".

I do apologize for this criticism of a worthy post in a worthwhile
thread but the "heat rises" thing kind of gets me going. 
Mike Baum 
email [email-masked]

---

From: [email-masked] (Nick Pine)
Date: 26 May 1996 16:53:26 -0400

Mike Baum <[email-masked]> wrote:
>>How about a walkout basement, since heat rises?...

>wrong, but doesn't heat move without regard to up or down.

Sure, in conduction and radiation.

>A more accurate description might be "hot air rises".

Right. And water above 39 F, and gases, etc.
 
For the last few days I've been trying to think of a way to make heat go down, 
in a house with high thermal mass walls and a heat-trap type "collector," in 
which one wall has an air heater outside the insulation, with an outlet near
the ceiling. Does anyone have any ideas on how to do that, simply? Wall
conduction? A ceiling fan? Some sort of slow-moving water?

Nick

---

From: William R Stewart <[email-masked]>
Date: Mon, 27 May 1996 07:37:16 -0400

> conduction? A ceiling fan? Some sort of slow-moving water?

You could use ducting and a fan, as you have mentioned before, to move the hot air
down to your basement thermal store.  You could then use the controls you mentioned
earlier to open dampers to let the hot air naturally convect upwards.

You could also use a low power pump for circulating water the collected heat, by 
using larger than normal pipes and have the minimum number of bends, elbows, and 
other head-adding components. The same convective controls can be used for 
distribution of heat by natural convection.

This is a classic problem active solar designers have been facing and resolving for
decades.

Cheers,

Will Stewart

---

From: [email-masked] (Nick Pine)
Date: 27 May 1996 11:22:59 -0400

William R Stewart  <[email-masked]> wrote:
>Nick Pine wrote:
>>...I've been trying to think of a way to make heat go down, in a house
>>with high thermal mass walls and a heat-trap type "collector," in which
>>one wall has an air heater outside the insulation, with an outlet near
>You could use ducting and a fan, as you have mentioned before, to move the
>hot air down to your basement thermal store.

That's how Norman Saunders, PE, gets warm air out of his attic warmstores
and into the living space... One 1/4 HP fan to move air down from the attic
(where he collects sun thru the roof, with his "$olar $taircase"), and
another to move house air thru his basement coolstore. Cliff house works
this way, with 10K pounds of water in the attic and 20K pounds of rocks in
the basement, in Weston MA. He says the annual operating cost is about $100
for the fans, but I suspect that cost is a bit out of date, since a 1/4 HP
motor probably uses 250 Watts full tilt, and that seems like a lot of power,
even the way Norman uses them, controlling the fans to 16 different speeds
with his custom-designed controller/data logger...

Norman is 80 years old now, and semi-retired, and he was a bit surprised
recently that a good rule of thumb for the cost of electricity is: 1 watt
used continuously costs about $1/year. He was also surprised that swimming
pool tube mat collectors are up to $4/ft^2. I'm sure he would be shocked
at rooftop collector prices. I doubt ever uses those. He also tends to avoid
plastic glazing, but he says he hasn't looked into that in a long time...

A 5' ceiling fan blowing air down through a hole in the ceiling might be
more efficient, to gently pressurize a central area, with some sort of large
air passages into adjacent rooms, eg a large supply grate in the floor of 
the central area to allow air to flow along the basement ceiling and up
into adjacent rooms thru large floor grates, with return air grates to the
attic in the ceilings of each room... The ceiling grates might each have
a 2 Watt $100 Honeywell motorized damper to control the temp in each room.

But I'd like to see Norman's system somehow simplified more and made more
cost-effective. It seems to me that it's better to have the water containers
on the ground instead of in the attic, so the weight and earthquakes are less
problematic, and we can use lower power fans to move air, or with the right 
design, motorized dampers and natural convection, or $12 automatic dampers
with bimetallic springs, that open or close at adjustable threshold temps.

>You could then use the controls you mentioned

Seems better to just collect the heat in a walk-out basement with a glazed
south wall to begin with. But... I like one way Norman collects heat in the
attic--he glazes the whole south wall of a house to make a huge low-thermal-
mass sunspace, a few inches away from the house wall itself, in some cases,
and lets the warm air rise up to the attic, where it stays trapped, like
heat in an igloo, with the entrance lower then the floor. That kind of solar
collection is completely passive, and doesn't even need dampers, but the
hot air outlet needs to be at the top of the wall, so the natural place to
store heat is in the attic, if you want to use the whole wall... Hmmm. 

>You could also use a low power pump for circulating water the collected heat,
>by using larger than normal pipes and have the minimum number of bends,
>elbows, and other head-adding components.

That's a good idea. You know, Monolithic Domes have remarkably even heat
distribution. They are made with about 2" of reinforced concrete inside
3" of foam insulation, so if the bottom heats up, say with sun through a
window, the warm air goes up to the ceiling and the concrete conducts the
heat back down to the floor level. They say a 200' hemisphere might only
have a 5 F temp difference from top to bottom... But we don't want that all
the time. It would be nice to leave the thermal mass in the dome ceiling hot,
and just bring the heat down controllably, on cloudy days. How can we do
that, a horizontal thermal break? Say an insulating ring of foam, 2" thick
x 3" wide, that breaks the concrete conductivity high up near the dome
ceiling, to isolate the ceiling from the walls, with some simple low-power
way to move heat across the insulation gap? 

On a cold day one might bring the heat down from the high thermal mass
ceiling into the conductive masonry walls of a dome or a room with a new
vaulted stone ceiling, or a house made with cement block walls, by moving
some water thru a few large short pipes that cross a thermal gap near the
ceiling, using a low-power, low-head pump. The pipes might be in a vertical
serpentine pattern, to inhibit natural convective waterflow.

>This is a classic problem active solar designers have been facing and
>resolving for decades.

Resolving more or less well... 

Seems to me this "active/passive" dichotomy has limited further usefulness.
What is more important to me is cost and reliability and performance. Is a 
solar heating system that uses 2 Watt dampers or 36 Watt fans to collect and
distribute 50 kW of sun "active"? Yes, if you are a purist... They used to 
call these "hybrid" systems, eg John Cristopher's 100% solar building in
Nashua, NH, which has a COP of 50 (2% fan power, 98% solar power.) But a
hot air furnace and blower burning 1 gph of oil might use 600 Watts while 
running, so it might have a fossil-fuel COP of 60 or so. Seems like we have
to improve heat distribution systems to raise these COPs. I think we can
make a simple, reliable system with a solar COP of 10,000, with excellent
temperature control, and no backup heat.

Nick

---

From: "Duane C. Johnson" <[email-masked]>
Date: Tue, 28 May 1996 10:11:47 -0700

Hi Nick;

> conduction? A ceiling fan? Some sort of slow-moving water?

This is just an idea to think about. I don't know if it works in the large scale
but it worked in a small model.

I made what looked like a Sterling engine to move air through a solar panel. The
engine was composed of 2 bellows connected to a crank shaft at 90deg. The cold air
(if I remember right) was forced into the collector through one way flapper valves.
The heated air was admitted into and released from the power bellows by a sliding
valve mechanism. These valves were, in the model ,made from scrap fiberglass PC 
board material. The slider would cover and uncover holes on the PC board.

The whole system had very low friction and needed to do very little work, except
to move the air, i.e. no output from the crankshaft. It ran for several years in my 
living room window. I did have to give it a shove every day to start it as it 
was not self starting.

I haven't seen anything similar described any where except for the high speed power
generating Sterlings. The little demo was successful probably because it was slow 
and used very low pressures.

What do you think. Could this be used as a self powered solar air mover? Can a fan
be used on the crankshaft for moving air in adjacent collectors?
-- 
CUL8ER
Duane C. Johnson
1825 Florence St.
White Bear Lake, MN, USA 55110-3364
http://www.geocities.com/SiliconValley/3027/
[email-masked]
(612)426-4766 h  635-5065 d

---

From: [email-masked] (Nick Pine)
Date: 28 May 1996 17:11:02 -0400

>Hi Nick;

Hi Duane :-)

>This is just an idea to think about. I don't know if it works in the large 
>scale but it worked in a small model.

OK...

>I made what looked like a Sterling engine to move air through a solar panel.
>The engine was composed of 2 bellows connected to a crank shaft at 90deg.
>The cold air (if I remember right) was forced into the collector through
>one way flapper valves. The heated air was admitted into and released from
>the power bellows by a sliding valve mechanism. These valves were, in the
>model ,made from scrap fiberglass PC board material. The slider would cover
>and uncover holes on the PC board.

I see :-)

>The whole system had very low friction and needed to do very little work,
>except to move the air, i.e. no output from the crankshaft. It ran for
>several years in my living room window. I did have to give it a shove every
>day to start it as it was not self starting.

Wow... :-) This sounds a little like Steve Baer's solar powered "Dubble Bubble
Diving Engine" (US Pat. No. 4,134,264), which was about 6' tall and made
1/2 Watt at 15 rpm :-) I admire your ingenuity...

>I haven't seen anything similar described any where except for the high
>speed power generating Sterlings.

You know, if you had patented your engine, Cummins might be paying you to
use your technique in their liquid sodium version with the concentrating
collector... Even if what you did seemed impractical, your patent might
have covered later more practical applications, altho collecting the money
is a different matter.

It sounds like you had fun and learned by building it, anyway...

>The little demo was successful probably because it was slow 

So did Steve's engine...

>What do you think. Could this be used as a self powered solar air mover?
>Can a fan be used on the crankshaft for moving air in adjacent collectors?

Seems like it  could,  but what I was looking for was some simple arrangement
of gases and pipes that might do the ceiling-to-floor heat transfer with no
moving parts. The best we've come up with so far is a pipe in the ceiling
slab and a pipe in the floor slab, and some sort of liquid that boils at,
say 75 F half that fills the floor pipe, with the tube to the ceiling pipe
exiting below the liquid level in the floor pipe, and a solenoid and
thermostat (or bellows and valve?) in the down vapor tube from the ceiling
pipe, so that when the room is cooler than 70 F or so, the valve opens to
let vapor from above push liquid up the liquid tube from below...

I wonder how to size something like that to deliver say, 20K Btu/hr with
the ceiling at 80F and the floor at 70F. The heat transfer rate through the
pipe walls might be about 50 Btu/hr-F... Hmmm. 80 ft^2 of pipe walls?

Nick

---

From: [email-masked] (Nick Pine)
Date: 29 May 1996 06:28:51 -0400

<[email-masked]> wrote:
>[email-masked] (Graeme Jessup) wrote:
>> [email-masked] 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?
 
>> >> 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
 
>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

---

From: [email-masked] (Dan Settles)
Date: Wed, 29 May 1996 15:41:16 -0500

> Nick

Hi Nick,

I took a few minutes to plot the data you posted.  It was interesting to
look at some real data points.  I was wondering under what conditions this
test was performed.  This doesn't appear to be the test box on the roof
that I have heard you talk about before.  Is this data from a solar closet
in a real house that someone is living in currently?  Can you give a few
more details regarding the size of the closet, water volume, collector
size, insulation, etc.  

Not that you seem to need any defense, but I enjoy reading the creative
and inexpensive solar heaing ideas you have.  Keep it up.

Dan Settles

---

From: Andy Kirby <[email-masked]>
Date: 30 May 1996 20:28:25 GMT

Here's a couple of sackless ideas (or maybe there noT)

Does anyone remember seeing a toy boat that used a
spirit burner to power the boat around a bath.
INside the boat was a tube which had a coil over the
burner flame. The inlet and outlet were on the rear of the boat.
I dunno what principle this device used but maybe there is
something in the principle.

Idea two how about using a peltier effect module to generate
electricity from the temperature difference and blow air/pump
water around the system. This would be self regulating. The greater
difference in temperature the greater the flow of heat transfering
medium.

Another interesting effect that may be of use is that used in the
gas refrigerator. I remember my great grandmother having one when
i was a kid. somehow the gas is burned and causes a cooling effect
by heating some part of a closed loop volatile liquid system.

OK the last idea heat pipes !!!!!
There have been some astounding papers published on these and
they seem to be good at moving heat from A to B. I gather that they
are used in satelite technology to transfer heat from the sunward
side of the device to the shadow side where the heat is disipated
into space.

Sorry but i just had to get those of my chest.
Unfortunately my knowledge in some of those areas is lacking so i can 
not illuminate further as yet.

Andy Kirby
([email-masked])

---

From: John Koch S1c <[email-masked]>
Date: Fri, 31 May 1996 10:39:00 -0400

> burner flame. The inlet and outlet were on the rear of the boat.
	Yes and you can get one from American Science & Surplus at
http://www.sciplus.com/.  It is in their online catalog in the
"experments" section and is listed as "Lil' Putt Putt". 
"Only" $11.95  :)

John Koch

---

From: [email-masked]
Date: Fri, 31 May 1996 18:05:08

>be used on the crankshaft for moving air in adjacent collectors?
---------------------------------------------
If you haven't already patented  :-)  this, could you provide an ASCII
drawing and rough dimensions?   Model Engineer magazine (a British mag)
had a article last October on a small stirling engine which could be
held in your hand...ran from sunlight on a windowsill or could run
sitting on top of a hot mug of coffee....
TIA
Jay

PS..anybody know about the small Stirling engine fans which are still
being manufactured in Pakistan; if they are imported into the USA?
These shouldn't cost very much and might be perfect for this
type of application (couple four together to make a self-starting fan).

---

From: [email-masked]
Date: Fri, 31 May 1996 19:10:51 -0400

In article <[email-masked]>, [email-masked]
(Nick Pine) wrote:

snip
> installation. Does anyone have better numbers?

How well insulated are the walls? or the door?  How about the unwanted
summer heat in the glazed sun space? A 3x4 Window Quilt at R5 will cost
$12/ft installed but also cuts up to 86% of heat gain in the summer.
There's a math exersise for you. Since they seal on all four sides of the
window frame with an unperforated sheet of mylar sandwiched between, they
also do an excellent job of stopping infiltration leaks.
  
> >> >> the propane water heater. 

snip

> >Ask for some real world data from any solar closets actually in existance.
 
charts and other verbage snipped

> ie T = 30 F + 300 Btu/hr x R1 = 330 F. Would you disagree with that, Dan?

Trust me here Nick, I have a sound working knowledge of the basics. My
point to you, which is the same point that I tried to make over a year ago
(and a few times since) is simply that you are not getting this heat into
the storage medium. Look at your own one day trial. Count your BTUs. Once
the house is up to a comfortable level (70-80F ?), VERY LITTLE of the
additional heat gets into storage.  Your 120-154F is wasted. Your storage
temp went from 73.3 to a low of 71.0 to a high of 76.8, while your living
area swung from 59.2 to 83.1. My wife would not be happy in this house.
The same square footage of flat plate collector connected to a real
storage tank would be well over 100F  on this same day. Connect that to a
real distribution system and the house would not have a 23 degree swing.
Yes, it's simple, yes, it's cheap, but no, it wont perform the way you are
expecting us to believe that it will. You will not get 120F into storage
when ambient temps are 40 or below. I doubt that you hit 95F without 5
days of 60F plus ambient. Am I wrong?

Its a good thing that you cant achieve those temps, too, because 120F in a
plastic drum is stupid. But, again, this is old territory.

snip 
> can't be done right, just that often, it isn't.

He's right. I see it all the time. And it all stems from a time when solar
customers were promised the world, and the world was never delivered.
Whether these promises were made by charlatans or well intentioned
contractors, engineers or architects that didn't know or didn't think
things all the way thru doesn't matter. What matters is disappointed
customers who now find it easy to believe the electric companies and the
plumbers who dont understand a simple solar dhw when they say "these
things dont work." 

By the way, three things make for a roof leak on a solar installation.
One, panels installed flat on the roof with little or no space between
roof and panel collecting debris and causing water damming. Two, roofers
who dont know the temps achievable and seal pipe penetrations with
roofer's tar or other low temp sealants, only to have the sealant melt
away when the system gets hot. And three, panels installed as a part of
the roof structure. In other words panels that form a portion of the
waterproof skin of the building. Different materials joined together and
required to heat up and cool down will move at different rates and in
different directions, causing leaks and infiltration. Obviously, inferior
materials (like wood which will get wet and rot with condensation even if
you can keep the leaks out, or plastic which deforms in heat and becomes
weak and brittle in sun light) will exacerbate this condition.

> costs and assumptions. Perhaps you have more accurate numbers.

OK, you're making me do math and that pisses me off. Whoa! $200 to carry
two panels on your roof? Not me buddy. A $50 tank? I'll buy all you can
deliver. All new materials might cost more like $3000-$3500 installed. 
Oops, I'm going the wrong way.  $2500 is reasonable if we're not buying
new panels.

No maintenance is a ridiculous assumption. Figure $125 every 4 years for
glycol change = $31.25 per year. Pumps, controls, sensors etc go bad. I
offer a warranty (even on 15 and 20 year old systems) that covers
everything except glycol and the plumbing parts that works out to about
$100 per year. By the way, if it were not a money maker, I'd raise the
cost. It makes my customers happy, so I offer it. This relates to a pump
or control replacement every 2.5 years, which will not happen.

So we have $3500 plus $100 per year for repair plus $31 per year for
maintenance plus $15 per year for operating costs = $4960 for 10 years.
 
Alright, 23 million Btu/year, equivalent to 180 gallons of oil/year. Hold
the phone, Nick. Look at your post. You are asking me to justify the cost
of purchase, installation, maintenance, repair and operating costs of
hardware designed to process and store these BTUs in a usable form.
Compared to the cost of delivering #2 heating oil to your door ("That's
right Buddy, dump it right here on the ground, I'll scoop it up later").
What about the hardware to process and store the oil? Maybe it was a gift
>from  God ("We just woke up this morning and... PRAISE THE LORD, there she
sat"). Tanks, burners, filters, delivery piping, vents, flues, etc. OK,
you've already got those things for your space heating equipment. What
does an indirect fired tank cost installed with all it's plumbing, pumps,
controls, etc.? $1500? $2000? A stand alone oil fired water heater? I
don't know.  But, you say, I use my space heat boiler as an instantaneous
dhw supply, so it's free. Bullshit. You have to oversize this boiler to
provide both space heat and dhw at the same time, which means higher
initial cost, faster wear and tear on the burner, boiler, flues, etc., in
addition to lower efficiency of BTU capture when it's only being used for
one or the other function, more losses into the house in the summer which
you now pay Three-Mile-Island to ac back out of the house, etc. Lets guess
$1500 installation for an 80% efficient burner, fair? But we have to get
that oil into heat and that heat into the water. 180 gallons at .8 /gallon
efficiency = 225 gallons or dollars per year. Plus $100 per year
maintenance and repair (burner jets and filters need to be replaced,
ignition systems checked, flues inspected, etc).

So, $1500 plus $100 per year for maintenance and repair plus $225 per year
operating costs = $4750 for ten years. If it's an indirect fired system,
add $7.50 per year operating costs for the same bronze pump that's in the
solar tank. Provided nothing goes wrong with the burner, oil tank, flue,
circulator or control system ( remember, I warrantied the solar).

But what if you're like most of us who pay the electric company to burn
the oil, change that into electricity and pipe that electricity into the
water tank? Lets buy the cheapest 30 gal, R7 (the solar tank is R19...
come to think of it, it's also got an internal, removeable heat exchanger
which means 1 cast iron pump which means only $7.5 per year opearating
costs -but I wont quibble), 5 Year warranty tank that we can find, $150.
Fair? Plus installation at $250. And one thermostat or element change in
ten years at $100. Assuming 100% efficiency at your electric element; one
kwH = 3413 BTU so 23 mill BTU = 6739 kwH. Multiplied by $.10 /kwH (your
figure) = $673.9 per year.

So, $400 tank plus $100 repair and maintenance, and $674 per year
operating costs = $7240. Even at $.07/kwH, $472 per year operating costs =
$5220. Now lets say you're on time of day use at $.15/kwH...

Let's review, shall we?

Ten years of oil - $4750... $4825 if we add a circulator...provided no
complications and ignoring unwanted summer heat gain because ac costs in
this country are negligible.

Ten years of electric - $5220 at $.07/kwH...$7240 at $.10/kwH.

Ten years of solar - $4960...$4885 if we use a single pump system.

You do the numbers on the second ten years when all three storage tanks
need replacement. I'll give you a hint, I want $1000 to replace your solar
tank. You've agreed that the panels should last 50 years.

As I tried to indicate in the discussion of oil burners, the realities
make the numbers real muddy, you're milage may vary. The solar with an
internal element in the upper third of the tank can be a stand alone
system, or we can pipe it into an existing oil burner for back up, or
both. The end result is that a properly sized solar dhw will pay back most
users in about 7 years. Bottled gas (propane) will cost similar to
electricity. Natural gas we dont wish to discuss. Just kidding, compared
to gas, solar will pay back in about 10 years.
 
> If you can read a book in your sunspace on a sunny winter afternoon, the

There you go again. The system you describe is a pipe dream. How many
square feet of Big Fins do you need to achieve only the part about "a
conventional water heater upstairs that seldom turns on?" I guarantee that
it's a great deal more than most readers are visualizing. By the way, it's
the best idea you've had yet for capturing some of your sunspace's massive
losses. After you've figured all the pipe, fittings, hangers, Big Fins,
glazings and replacement glazings, I'd bet that I can match or beat your
performance with a similar dollar outlay in commercial panels.

Again, I am not saying that it wont work. But it will not work as well as
you lead the reader to believe.

Shoddy workmanship, second rate materials, half-baked logic and the
frustration caused by spending time, energy and money on items that dont
live up to expectation are exactly the cause of the sad state of the solar
industry today. 

Nick, you hold a peculiar responsibility here. The forcefulness of the way
you post your arguments, the overwhelming and mind numbing use of
mathematics and formulas (if you can't dazzle them with brillance...), and
the shear proliferation of your posts make some think that you know what
you are saying. To say nothing about your self appointed importance, 
"designer of low-cost, high-performance solar houses." If you propagate a
theory as fact and it doesn't quite pan out, or overlook a basic componet,
it becomes a detriment to all of us.

Dan

---

From: [email-masked] (Nick Pine)
Date: 1 Jun 1996 05:22:34 -0400

<[email-masked]> wrote:/>(Nick Pine) wrote:

Good morning Dan...

>How well insulated are the walls? or the door?

I don't know... Hmmm. Suppose you had a big sunspace with R1 glazing, say
a 12 wide x 16' tall sunspace, 8' wide at the base, with an R30 house wall
behind it and an R8 door in the wall. Does it make sense to add $12/ft^2
(installed price) R5 Window Quilts to the $1/ft^2 (material price) glazing?
Or just close the door or close the damper. I guess it depends on whether
you plan to heat and use the sunspace often at night. I could see snuggling
under a blanket for a few minutes after dinner, and looking up at the stars
in a cold sunspace at night, or sleeping out there in a sleeping bag, once
in a winter while, with the door to the house closed...

>How about the unwanted summer heat in the glazed sun space?

How about an overhang, some greenhouse shadecloth, runner beans, grapes,
trumpet vines, clematis, etc, and some small screened vent doors that are
open all summer?

>A 3x4 Window Quilt at R5 will cost

It's nice to have better numbers for this. I was going by Shelter Institute's
price of $3-5/ft^2, just for the material, with free homeowner labor. A 15
cent/ft^2 piece of 80% absorbing greenhouse shadecloth hung outside the
glazing will reduce summer sun input by 80%, and it only needs to be moved 
twice a year, and it makes the glazing last longer, if plastic... I wonder
what it means, exactly, to say that Window Quilt at $12/ft^2, installed,
"cuts 86% of heat gain"? 

>There's a math exersise for you.

Where's the math exercise? Why is it for me? Perhaps this is one for you.

>Since they seal on all four sides of the window frame with an unperforated
>sheet of mylar sandwiched between, they also do an excellent job of stopping
>infiltration leaks.

Sounds good. I've often wondered whether these numbers like "R5" include
the effects of air leaks around the edges of the Window Quilt. Do they?
Was that R5 as measured or R5 bulk insulating material? If Window Quilts are
movable (and moved, with daily manual labor), it seems to me there must be
some tiny gap around the edge, eg 1/64"? (I'm thinking of Will's "tracked
and easily movable window insulation here, but maybe that doesn't apply.)
I wonder what a gap like would do to an R5 insulator in front of a 3x4 R2
window on a 30 F day? Let's see... If the room were 70 F and the Quilt were
R5, and it worked perfectly, we'd have (70-30)12 ft^2/(R5+R2) = 68.6 Btu/hr
of heat flowing thru the window. If the gap were like a little chimney,
allowing (1/64")/12x3'(16.6)sqrt(4(70-30)) = 0.05 cfm of 70 F air to flow
up between the Quilt and the window, that would only add another 0.05(70-30)
= 2 Btu/hr to the heat loss, and a little condensation, perhaps. So...
I don't know... I guess they wouldn't sell these things if condensation
were much of a problem, but then condensation is not normally a problem
on windows without Window Quilts. So... I dunno. 

>> >...can you actually achieve a temperature above 90 F with this set up?

>Trust me here Nick, I have a sound working knowledge of the basics.

OK... Would you disagree with the line above? I'm sure you're familiar
with the solar collector stagnation problem. This is a more controlled
version of that. I am not sure that you have a sound working knowledge
of "the basics." Or even that we are talking about the same "basics."
I think of "Ohm's law for heatflow" as basic, and I don't know if you are
familiar with that or not. Norman Saunders, PE, wrote a book called
_Solar Basics_ in 1974 (4th edition :-) It's not a simple book. 

>My point to you, which is the same point that I tried to make over a year ago
>the storage medium. Look at your own one day trial. Count your BTUs.

We did that once... About 55% of the sun that fell on the closet glazing 
ended up in the water storage. I don't recall the details now, but the
water was not very warm at the time, and the day was not very cold. If you
look in Steve Baer's _Sunspots_ book, on pages 114-116, you will see a
bunch of experiments he did with a rock storage/convective air loop system,
using a similar air-type collector, with similar efficiencies. You can
see similar efficiencies in Duffie and Beckman's _Solar Engineering of
Thermal Processes_ and Andy Zaugg's air heater book.

>Once the house is up to a comfortable level (70-80F ?), VERY LITTLE of the
>additional heat gets into storage.

Why do you say that, exactly? There's a graph of some data we measured in
our Congress paper that shows almost all of the additional solar heat
getting in to the water store on a sunny day, with a 70 F room temp...

>Your 120-154F is wasted.

I'm not sure what you mean by that. Hot air is hot air, and it isn't too hard
to predict the response of a cooler object sitting in hot air, these days. 
It gets warmer. Take a look at Figure 1 on page 22.1 of the 1993 ASHRAE
Handbook of Fundamentals.

>Your storage temp went from 73.3 to a low of 71.0 to a high of 76.8,
>while your living area swung from 59.2 to 83.1. My wife would not be
>happy in this house.

Neither would most people, I suppose. The data I posted was taken last
November 4, on the very first morning we had our box set up on the roof,
as soon as we had things plugged together and working, and it's not typical
of what you would see in a real house. We have piles and piles of data,
but little of it is typical of what you would see in a house, because we
were experimenting, and because of my carpentry talents, which resulted in
a box with R5 walls :-) 

>real distribution system and the house would not have a 23 degree swing.

I think we are comparing expensive apples and inexpensive oranges here, and
I'm not sure what you mean by what you say above (wouldn't that depend on
the size of the tank, etc, etc?), and you really do seem to like rooftop
collectors, perhaps because you sell them. I don't sell anything... I do
try to give away money sometimes, without much success :-)

>when ambient temps are 40 or below.

I wonder why you say that? We could do a few numbers here, but that just
seems to irritate you, Dan. You just say "it won't work." I say it will.
I have numbers. You have chutzpah. Neither of us has real data for this.

>I doubt that you hit 95F without 5 days of 60F plus ambient. Am I wrong?

I don't recall. But that could well be true of our little 2'x4'x8' test box.
Recall the R5 walls...

>plastic drum is stupid. But, again, this is old territory.

You know, I've never tried filling a 55 gallon drum with 120 F water. Sounds
like an interesting but tedious experiment, and a waste of hot water, but
learning is expensive, no? Perhaps I'll use Ursinus College water. Do you
have a plastic 55 gallon drum? I tried filling a 2 liter plastic soda bottle
with 130 F water, and that seemed fine. I tried filling the bottle with
boiling water, and it shrank to 1 liter... So, who knows? Do plastic drums
in Utah warehouses often melt? It seems to me there would be no structural
problem with 130 F water in unpressurized plastic drums, stacked 2-high, and
you think "it's stupid." There's not much point in our arguing here like
the old Greek scientists who debated about and discussed nature without ever
observing it and decided, for example, that porcupines pull out their spines
and throw them at their animal enemies as a defense. We should just try this,
or look up some specs, or something.

>customers were promised the world, and the world was never delivered.

A sad time, that.

>roof and panel collecting debris and causing water damming.

That's too bad, because the collectors might be a bit warmer underneath
without all the cold wind whistling under their backsides, and carrying
off that heat to the outdoors. Sunspaces come to mind :-)

>Two, roofers who dont know the temps achievable and seal pipe penetrations
>with roofer's tar or other low temp sealants, only to have the sealant melt
>away when the system gets hot.

I can imagine that happening.

>And three, panels installed as a part of the roof structure. In other words
>panels that form a portion of the waterproof skin of the building.

Ah, you are talking about my solar attic, perhaps, covered with 600 ft^2
of $1/ft^2 non-leaky (so far) single layer corrugated polycarbonate plastic?

>Different materials joined together and required to heat up and cool down
>will move at different rates and in different directions,

Yes.

>causing leaks and infiltration.

Not necessarily. That depends on the design.

>Obviously, inferior materials (like wood which will get wet and rot with
>condensation even if you can keep the leaks out, or plastic which deforms
>in heat and becomes weak and brittle in sun light) will exacerbate this
>condition.

That may not matter. When you step into a car, do the tires collapse?

>> install them on the roof... and collect 1,000 Btu/ft^2/day of sun every day,

>OK, you're making me do math and that pisses me off.

So I notice :-) Perhaps you also think I'm attacking your livelihood.

>Whoa! $200 to carry two panels on your roof? Not me buddy. A $50 tank?
>I'll buy all you can deliver.

I was trying to be generous in this exercise.
To make rooftop panels look good, economically.

>All new materials might cost more like $3000-$3500 installed. 

What do we do when we run out of old panels?

>or control replacement every 2.5 years, which will not happen.
 
OK.

>maintenance plus $15 per year for operating costs = $4960 for 10 years.
  
OK.

>hardware designed to process and store these BTUs in a usable form.

I don't think I asked you to do that.

>right Buddy, dump it right here on the ground, I'll scoop it up later").

I don't think I asked you to do that either.

>sat").

This is an interesting oil delivery system. It might work in Texas...

>Tanks, burners, filters, delivery piping, vents, flues, etc. OK,
>you've already got those things for your space heating equipment.

Maybe, maybe not.

>What does an indirect fired tank cost installed with all it's plumbing, pumps,
>dhw supply, so it's free.

I said that?

>Bullshit. You have to oversize this boiler to provide both
>space heat and dhw at the same time, which means higher
>$1500 installation for an 80% efficient burner, fair?

Um, that's fine with me. Whatever you say, Dan.

>But we have to get
 
Efficiency can be a bit higher these days, eg with an Intelligen system,
making electricity too, and only sending 7% of the oil's heat up the chimney.  

>circulator or control system ( remember, I warrantied the solar).

A little fin-tube pipe in a solar closet seems attractive here.

>figure) = $673.9 per year.

OK... Does this trail have a map? :-)

>Let's review, shall we?

OK... I guess we are sufficiently confused.

 
 
>tank. You've agreed that the panels should last 50 years.

I guess I did. Do I have to do the numbers?
 
>to gas, solar will pay back in about 10 years.

OkOkOk. I believe you. But wouldn't it be nice if it paid back in 1-3 years,
and added some daytime floor space to your house, and gave you a place to
grow things and store your lawn mower? (I don't have a lawn mower.)

 
>> >polyethelene sheets every 2 or 3 years.

Oops, I forgot to do that. They are not worth the cost after 50 years of
replacing polyethelene sheets every 2 or 3 years. There, I did exactly
what you wanted. I even mispelled polyethylene.

>There you go again. The system you describe is a pipe dream.

No. I saw a system exactly like that near Princeton, NJ in 1980, and as
I recall, Big Fins were Zomeworks' most successful product... I think there
are lots of systems just like that out in the Real World (tm.)

>How many square feet of Big Fins do you need to achieve only the part about
>"a conventional water heater upstairs that seldom turns on?"

That depends on the hot water load, the climate, the sunspace glazing,
and what we mean by "seldom."

>I guarantee that it's a great deal more than most readers are visualizing.

The system I saw had 50-100 ft^2, about 6" under the sunspace glass, as
I recall, with 1-2" gaps between the fins to let the sun filter through.
It looked very nice, and worked very well. The homeowners were quite happy
with it. I remember being surprised that one could make hot water like that
with bare surfaces in a sunspace, but then I did the math, and it seemed
reasonable. Suppose you have 1 ft^2 of bare something (it might work better
with a little foamboard on the back, or something, but these were just bare
Big Fins, painted black). If the water temp is, say 100 F (picking a number
between 60 and 130), what would the solar collection efficiency be, in full
sun, in an 80 F sunspace? For still air, U is about 1.5 Btu/hr-F, and the
fin has two sides, so about 300 Btu/hr goes in to the water, and another
(100-80)2 ft^2x1.5 = 60 Btu/hr leaks out into the sunspace air, for a
collection efficiency of (300-60)/300 = 80%. Not bad, and the "waste heat"
goes into the house, and the panels are simple and could be cheap in large
quantities, and with a little care, the sunspace can be kept above freezing, 
so no antifreeze or heat exchangers are needed. Looks good to me...

I think there are lots of solar water heaters in Israel that have collectors
with selective surfaces sitting right out in the open, with no glazing, even.

>By the way, it's the best idea you've had yet for capturing some of your
>sunspace's massive losses.

Hey, faint praise! But who cares about "massive losses"? The sun is free.
Think of how much is wasted on every football field. Quick, Dan, go glaze
over those fields! What matters to me is simplicity and performance and
economics. 

>After you've figured all the pipe, fittings, hangers, Big Fins,

How much would you like to bet? Shall we count the floorspace at $20/ft^2?

>you lead the reader to believe.

It seems pointless to argue about how well Big Fins work.
There are lots of them in the field, and they work very well.

>live up to expectation are exactly the cause of the sad state of the solar

I think a lot of that was fueled by tax credits.

>Nick, you hold a peculiar responsibility here.

Correct. I feel a need to present the truth as I see it.

>The forcefulness of the way you post your arguments,

Ah the joy of life intense, as opposed to live in houses...

>the overwhelming and mind numbing use of mathematics and formulas

Some minds are more easily numbed than others, but this is mostly high
school arithmetic. I find it much simpler than IRS forms.

>(if you can't dazzle them with brillance...),

Baffle 'em with bullshit? That's not my intention at all.

>and the shear proliferation of your posts make some think that you know what
>you are saying.

Remarkable, isn't it? Just tell the truth, and some people believe you.

>To say nothing about your self appointed importance, "designer of low-cost,
>high-performance solar houses."

Did I say that? No... And in fact I haven't ever helped design a house. Not
for long, anyway. I'm a mere engineer, not an architect. I started helping
design a house a few months ago, with a local builder who'd sold his clients
on using me as their solar design consultant, but at our last meeting, the
architect began screaming at me and ordered me out of the room. Can't imagine
why :-) It might have had something to do with the fact that it was a fixed-
price design job, and the builder and architect decided they wanted a larger 
share of that money, after the clients were hooked.

>If you propagate a theory as fact and it doesn't quite pan out, or
>overlook a basic componet, it becomes a detriment to all of us.

Only to those who believe it can work, and find it cannot. 

You don't seem to be in that camp.

You are not a pioneer.

Nick

---

From: [email-masked] (paul milligan)
Date: 1 Jun 1996 11:15:35 GMT

In article <[email-masked]>,
   John Koch S1c <[email-masked]> wrote:

~~>	Yes and you can get one from American Science & Surplus at
~~>http://www.sciplus.com/.  It is in their online catalog in the
~~>"experments" section and is listed as "Lil' Putt Putt". 
~~>"Only" $11.95  :)
~~>
~~>John Koch

	Which said link can in turn take you to

http://www.eskimo.com/~billb/ , which has lots of neat creative science

stuff, including :

http://www.eskimo.com/~billb/supliers.html

Which lists lots of neat suppliers !  Good links to browse when you get a
 chance !

_________________________________________________________
No Disclaimer needed - This is my own PPP account, and my
employer doesn't care what I think anyway !  :-)
_________________________________________________________

The SEHVAC FAQ is at: http://www.elitesoft.com/sci.hvac/
My humble personal pages are at: http://www.webbuild.com/~pjm/index.html

---

From: [email-masked] (gcp)
Date: Wed, 29 May 1996 21:05:52 GMT

>conduction? A ceiling fan? Some sort of slow-moving water?

I presume this is in a solar house?

If you want something purely passive you might try a black walled
'chimney' to pull the air out, with the intake being in your sunspace.
I believe the technique has been used to ventilate commercial
glasshouses.
You may think this is a waste of the heat going up the chimney,
but the sun is provided free and the system will operate just when it
is needed.
It's only an idea.   :-)