Passive Solar Heating Panels

[Morris Dovey]

Over the past month I've put together a web page describing a passive
solar heating panel capable of providing 100% of the heat needed to
maintain a comfortable temperature 24/7 in a conventional structure with
reasonably good insulation and which is reasonably snug. The panels need
to be installed in unshaded south-facing walls.

These panels work reasonably well in overcast conditions and will
produce heat whenever there's enough sunlight to read a newspaper. They
work unreasonably well in clear-sky direct sunlight.

Five years' experience in central Iowa indicates that each square foot
of panel area can heat approximately 125 cubic feet of air with enough
additional heat for storage to maintain that much air at a comfortable
temperature for more than a week of completely dark days.

My plan is to add both English and metric 3-D DXF/DWG files and an
assembly animation, and to clean up some of the stuff that I don't think
I presented as well as I might have. I didn't hold off because I have
friends outside the US who need the info now.

The web page will remain a work in progress for some time. If you find
the content interesting, I suggest linking to the page rather than
downloading a snapshot - and I ask that you not re-publish the page or
any of the content until I have it in final form.

The page is at http://www.iedu.com/Solar/Panels

--
Morris Dovey

[Jim Wilkins]

"Morris Dovey" <mrd...@iedu.com> wrote in message
news:kdpnbh$gb6$1...@speranza.aioe.org...

>
> Over the past month I've put together a web page describing a
> passive solar heating panel capable of providing 100% of the heat
> needed to maintain a comfortable temperature 24/7 in a conventional
> structure with reasonably good insulation and which is reasonably
> snug. The panels need to be installed in unshaded south-facing

> walls.....

>
> The page is at http://www.iedu.com/Solar/Panels

> Morris Dovey

The local plastics supplier wanted nearly twice this price:
http://www.greenhousemegastore.com/product/polycarbonate-panel-8mm-clear

My experiments seem to show that one layer of treated polycarbonate
over a cheaper clear PVC sheet is adequate to withstand storms and
falling branches. The PVC is stiffer and sags less under a snow load.
They are the corrugated sheets from HD and Lowes, so I can quickly
replace a damaged panel without having to store spares. The rounded
PVC and trapezoidal polycarbonate corrugations make only intermittent
line contact, with mostly thin insulating airspace between them. They
make good roofing but I don't think they look good enough for the wall
of a home.

Do you know of a decent-looking durable reflective material besides
plywood siding to replace or cover the panels with during the summer?
Large painted panels are difficult to store densely without scratching
them, as I know from managing theatre scenery. The volume the flats
took up would be excessive for a home.
jsw

[Morris Dovey]

On 1/24/13 7:24 AM, Jim Wilkins wrote:
> "Morris Dovey" <mrd...@iedu.com> wrote in message
> news:kdpnbh$gb6$1...@speranza.aioe.org...
>>
>> Over the past month I've put together a web page describing a
>> passive solar heating panel capable of providing 100% of the heat
>> needed to maintain a comfortable temperature 24/7 in a conventional
>> structure with reasonably good insulation and which is reasonably
>> snug. The panels need to be installed in unshaded south-facing
>> walls.....
>>
>> The page is at http://www.iedu.com/Solar/Panels
>> Morris Dovey
>
> The local plastics supplier wanted nearly twice this price:
> http://www.greenhousemegastore.com/product/polycarbonate-panel-8mm-clear

The retail price of a 6mm sheet was ~$30 when I began the project.

> My experiments seem to show that one layer of treated polycarbonate
> over a cheaper clear PVC sheet is adequate to withstand storms and
> falling branches. The PVC is stiffer and sags less under a snow load.
> They are the corrugated sheets from HD and Lowes, so I can quickly
> replace a damaged panel without having to store spares. The rounded
> PVC and trapezoidal polycarbonate corrugations make only intermittent
> line contact, with mostly thin insulating airspace between them. They
> make good roofing but I don't think they look good enough for the wall
> of a home.

As you probably figured out, aesthetics was not one of my primary design
considerations - and cost was only a secondary consideration. Some
people don't like /black/ panels. :-)

My experience with vertically-installed panels has been that snow load
considerations don't apply.

> Do you know of a decent-looking durable reflective material besides
> plywood siding to replace or cover the panels with during the summer?
> Large painted panels are difficult to store densely without scratching
> them, as I know from managing theatre scenery. The volume the flats
> took up would be excessive for a home.

The vertical orientation and flat surface appears adequate to minimize
summer heating in at least northern US and southern CA.

I think your covers need only be opaque (not reflective) if you provide
an adequate air space between cover and glazing - but it makes more
sense to me to eliminate the need for them.

--
Morris Dovey

[j]

On 1/24/2013 8:24 AM, Jim Wilkins wrote:
> "Morris Dovey" <mrd...@iedu.com> wrote in message
> news:kdpnbh$gb6$1...@speranza.aioe.org...
>>
>> Over the past month I've put together a web page describing a
>> passive solar heating panel capable of providing 100% of the heat
>> needed to maintain a comfortable temperature 24/7 in a conventional
>> structure with reasonably good insulation and which is reasonably
>> snug. The panels need to be installed in unshaded south-facing
>> walls.....

Very nicely done. The part about air flow characteristics is fabulous
knowledge.

>>
>> The page is at http://www.iedu.com/Solar/Panels
>> Morris Dovey
>
> The local plastics supplier wanted nearly twice this price:
> http://www.greenhousemegastore.com/product/polycarbonate-panel-8mm-clear
>
> My experiments seem to show that one layer of treated polycarbonate
> over a cheaper clear PVC sheet is adequate to withstand storms and
> falling branches. The PVC is stiffer and sags less under a snow load.
> They are the corrugated sheets from HD and Lowes,

The Lowes product is different than the HD.The HD SunTuff has a UV
coating while the Lowes does not need it. I could never get thin flat
polycarb here, which surprised me. It all had to be shipped.

so I can quickly
> replace a damaged panel without having to store spares. The rounded
> PVC and trapezoidal polycarbonate corrugations make only intermittent
> line contact, with mostly thin insulating airspace between them. They
> make good roofing but I don't think they look good enough for the wall
> of a home.

I'm less concerned about conventional appearance, which is fortunate for me.

I've been using mylar as the interior glazing. I have a variety of ways
I've tried this. The UV coating on the SunTuf protects the mylar.

Currently I'm redoing the solar hot water. A frame cut from sheet
polyiso is covered on both sides by 1 mil mylar. This sits inside the
collector and is then covered by SunTuf. Typically the corrugated Suntuf
is shortly above that. About a half inch air space is about right, which
is the thickness of the polyiso. In the home,the storm frames are also
1/2", but made of wood.

>
> Do you know of a decent-looking durable reflective material besides
> plywood siding to replace or cover the panels with during the summer?
> Large painted panels are difficult to store densely without scratching
> them, as I know from managing theatre scenery. The volume the flats
> took up would be excessive for a home.

The aluminized heavy duty tarps from Northern Tool might work, I'm well
pleased with the durability of them.

As far as sun temps the vertical orientation plus summer foliage is all
I need. Site specific, of course.

Jeff

> jsw
>
>

[j]

On 1/23/2013 5:14 PM, Morris Dovey wrote:
>
> Over the past month I've put together a web page describing a passive
> solar heating panel capable of providing 100% of the heat needed to
> maintain a comfortable temperature 24/7 in a conventional structure with
> reasonably good insulation and which is reasonably snug. The panels need
> to be installed in unshaded south-facing walls.
>
> These panels work reasonably well in overcast conditions and will
> produce heat whenever there's enough sunlight to read a newspaper. They
> work unreasonably well in clear-sky direct sunlight.
>
> Five years' experience in central Iowa indicates that each square foot
> of panel area can heat approximately 125 cubic feet of air with enough
> additional heat for storage to maintain that much air at a comfortable
> temperature for more than a week of completely dark days.

I've had a bit more time to go through this, although I haven't absorbed
it all.

It seems to me that you must be close to optimum, as far as getting the
amount of heat out of this. That you can generate heat with so little
light is striking.

A few notes.

I notice that you said a thin coat of gloss worked better than flat
black. This strikes me as similar to the way selective coatings work.
The absorption is slightly lower but the re-radiative losses are much
less. Certainly important in a cold climate.

I note the distance from the absorber fins to the glazing and the back
is on the order of a half inch. Larger distance seem to create their own
air currents and are counter productive, that was not obvious to me!

I also note your point that the object is to heat the air and not the
absorber! I've made some progress here, IR measurements of my absorber
(black felt) show it be a good bit cooler than the air between it and
the glazing. In my collector I'm pulling air from the collector and
pushing it into the old air vents.

The fin rolling "machine" is very interesting. I made a series of jigs
to form aluminum around the copper risers. That and riveting it all
together was extremely exhausting. Perhaps some details of the machining
would be useful.

I've altered my own solar air collector several times as money and
experience has allowed. The current geometry is too much depth, but that
was largely determined by the geometry of the house and the jalousie
windows. On the plus side the cats love to spend time inside the
collector (the house side).

Cheers,
Jeff

[Morris Dovey]

On 2/3/13 11:53 AM, j wrote:

> It seems to me that you must be close to optimum, as far as getting the
> amount of heat out of this. That you can generate heat with so little
> light is striking.

I don't think I'm as close as I'd like to be - but future improvements
are likely to be in smaller increments.

Coating the back plenums with high gloss paint might make a significant
improvement to air flow. Back when I was building panels I didn't think
so, but I'm still learning - and think this worth trying.

The shape and spacing of the fins can almost certainly be improved, but
I think that'll need to be done by someone with the right combination of
physics/math/geometry skills - which I don't have. There's a gentleman
who lives in southern France who might be able to nail this down, but
all my contact info for him was lost when my old HP machine
self-destructed. :-(

> A few notes.
>
> I notice that you said a thin coat of gloss worked better than flat
> black. This strikes me as similar to the way selective coatings work.
> The absorption is slightly lower but the re-radiative losses are much
> less. Certainly important in a cold climate.

There's a lot of room for exploration here. By the time I'd built my
last panel I'd realized that what I'd been calling an absorber shouldn't
/be/ an absorber - that's just the word everyone wants to hear. Ideally
it's purely a reflector. :-)

> I note the distance from the absorber fins to the glazing and the back
> is on the order of a half inch. Larger distance seem to create their own
> air currents and are counter productive, that was not obvious to me!

Now you're sounding a lot like me. :-) It turns out that there's a lot
of behavior that's best labeled counter-intuitive. My favorite joke on
myself was that my level of ignorance was colossal and growing at an
exponential rate!

> I also note your point that the object is to heat the air and not the
> absorber! I've made some progress here, IR measurements of my absorber
> (black felt) show it be a good bit cooler than the air between it and
> the glazing. In my collector I'm pulling air from the collector and
> pushing it into the old air vents.

I think this notion of (as much as possible) heating only the air is a
key concept. AFAICT a hot collector is necessarily a lossy collector.

> The fin rolling "machine" is very interesting. I made a series of jigs
> to form aluminum around the copper risers. That and riveting it all
> together was extremely exhausting. Perhaps some details of the machining
> would be useful.

It's just a forming press with a cutting blade on the infeed end. My
thought was to use a stepper to pull ribbon from the spool, an empty
spool to ballast a loop of ribbon, and another stepper to measure ribbon
from the loop into the press. A pair of LED/photodetectors would let the
controller sense when to feed from the spool and when to stop feeding
(all copied from some of the early computer tape devices). The inset
detail in the sketch shows the ribbon positioning I actually used with
my manual press.

> I've altered my own solar air collector several times as money and
> experience has allowed. The current geometry is too much depth, but that
> was largely determined by the geometry of the house and the jalousie
> windows. On the plus side the cats love to spend time inside the
> collector (the house side).

(I'm imagining some very contented cats!)

--
Morris Dovey
http://www.iedu.com/Solar

[j]

On 2/3/2013 6:17 PM, Morris Dovey wrote:
> On 2/3/13 11:53 AM, j wrote:

OT for a moment...

My sewer line here is blocked, I've tracked it with great difficulty, by
digging and looking. It takes a right into my backyard and then another
right so it circles the house.

So, I found the line is blocked between the sidewalk and the street. So,
we dug down and struck... the new (and unused) gas line, 6" under that
the crushed sewer pipe.

I call the city at 3PM and they tell me to file a damage report with the
gas company. However at 5PM someone from the city shows up and says the
city will fix it by Sunday.

Just now, someone came out and marked the water and sewer lines, the
ones that I had no idea where. I've never seen anything like it, he had
a collapsible metal divining rod and just walked across the pavement. It
snapped to the side and he marked. In fact, he marked all the water and
sewer lines, just like that, in no time. And it matches exactly.

So, I am thoroughly impressed with the speed and psychic powers of this
city!

</OT>

>
>> It seems to me that you must be close to optimum, as far as getting the
>> amount of heat out of this. That you can generate heat with so little
>> light is striking.
>
> I don't think I'm as close as I'd like to be - but future improvements
> are likely to be in smaller increments.

It would seem so, the base heater designer is very good.

>
> Coating the back plenums with high gloss paint might make a significant
> improvement to air flow. Back when I was building panels I didn't think
> so, but I'm still learning - and think this worth trying.

small increments, as you said.

>
> The shape and spacing of the fins can almost certainly be improved, but
> I think that'll need to be done by someone with the right combination of
> physics/math/geometry skills - which I don't have. There's a gentleman
> who lives in southern France who might be able to nail this down, but
> all my contact info for him was lost when my old HP machine
> self-destructed. :-(

Ouch.

>
>> A few notes.
>>
>> I notice that you said a thin coat of gloss worked better than flat
>> black. This strikes me as similar to the way selective coatings work.
>> The absorption is slightly lower but the re-radiative losses are much
>> less. Certainly important in a cold climate.
>
> There's a lot of room for exploration here. By the time I'd built my
> last panel I'd realized that what I'd been calling an absorber shouldn't
> /be/ an absorber - that's just the word everyone wants to hear. Ideally
> it's purely a reflector. :-)

Perhaps, re-radiator...

>
>> I note the distance from the absorber fins to the glazing and the back
>> is on the order of a half inch. Larger distance seem to create their own
>> air currents and are counter productive, that was not obvious to me!
>
> Now you're sounding a lot like me. :-) It turns out that there's a lot
> of behavior that's best labeled counter-intuitive. My favorite joke on
> myself was that my level of ignorance was colossal and growing at an
> exponential rate!
>
>> I also note your point that the object is to heat the air and not the
>> absorber! I've made some progress here, IR measurements of my absorber
>> (black felt) show it be a good bit cooler than the air between it and
>> the glazing. In my collector I'm pulling air from the collector and
>> pushing it into the old air vents.
>
> I think this notion of (as much as possible) heating only the air is a
> key concept. AFAICT a hot collector is necessarily a lossy collector.

That makes sense.

>
>> The fin rolling "machine" is very interesting. I made a series of jigs
>> to form aluminum around the copper risers. That and riveting it all
>> together was extremely exhausting. Perhaps some details of the machining
>> would be useful.
>
> It's just a forming press with a cutting blade on the infeed end. My
> thought was to use a stepper to pull ribbon from the spool, an empty
> spool to ballast a loop of ribbon, and another stepper to measure ribbon
> from the loop into the press. A pair of LED/photodetectors would let the
> controller sense when to feed from the spool and when to stop feeding
> (all copied from some of the early computer tape devices).

Yowza.

The inset
> detail in the sketch shows the ribbon positioning I actually used with
> my manual press.

I'm struck by the amount off the shelf and cheap technology available.
And the Arduinos and the like to control them. Anything is possible,
parts you can't get you can send off to the 3D service bureau to get made.

>
>> I've altered my own solar air collector several times as money and
>> experience has allowed. The current geometry is too much depth, but that
>> was largely determined by the geometry of the house and the jalousie
>> windows. On the plus side the cats love to spend time inside the
>> collector (the house side).
>
> (I'm imagining some very contented cats!)

Oh yeah, on a cold day it is "the" spot.

Cheers,
Jeff
>

[Morris Dovey]

On 2/5/13 11:42 AM, j wrote:

> My sewer line here is blocked, I've tracked it with great difficulty, by
> digging and looking. It takes a right into my backyard and then another
> right so it circles the house.
>
> So, I found the line is blocked between the sidewalk and the street. So,
> we dug down and struck... the new (and unused) gas line, 6" under that
> the crushed sewer pipe.
>
> I call the city at 3PM and they tell me to file a damage report with the
> gas company. However at 5PM someone from the city shows up and says the
> city will fix it by Sunday.
>
> Just now, someone came out and marked the water and sewer lines, the
> ones that I had no idea where. I've never seen anything like it, he had
> a collapsible metal divining rod and just walked across the pavement. It
> snapped to the side and he marked. In fact, he marked all the water and
> sewer lines, just like that, in no time. And it matches exactly.
>
> So, I am thoroughly impressed with the speed and psychic powers of this
> city!

That /is/ impressive! Tell us the name of this exceptional city! :-)

> I'm struck by the amount off the shelf and cheap technology available.
> And the Arduinos and the like to control them. Anything is possible,
> parts you can't get you can send off to the 3D service bureau to get made.

See http://portabee3dprinter.com - at under $500 for the kit I think I'd
prefer to be my own service bureau for all but precision parts, but I
think I'd be inclined to pay a bit more for the fully-assembled version.
The additive technology is moving toward the point where we should
(soon) be able to print circuit boards and houses.

>>> I've altered my own solar air collector several times as money and
>>> experience has allowed. The current geometry is too much depth, but that
>>> was largely determined by the geometry of the house and the jalousie
>>> windows.

I'm not sure you can actually have too much depth, but suspect that
there's a point of diminishing returns. I'm fairly sure that with my
(nominal) 8" panel depth, I hadn't reached it yet.

[Morris Dovey]

On 2/5/13 3:44 PM, Morris Dovey wrote:

> See http://portabee3dprinter.com - at under $500 for the kit I think I'd
> prefer to be my own service bureau for all but precision parts, but I
> think I'd be inclined to pay a bit more for the fully-assembled version.
> The additive technology is moving toward the point where we should
> (soon) be able to print circuit boards and houses.

Oops! http://www.youtube.com/watch?v=JdbJP8Gxqog

--
Morris Dovey
http://www.iedu.com/Solar/

[amdx]

On 2/5/2013 11:42 AM, j wrote:
> On 2/3/2013 6:17 PM, Morris Dovey wrote:
>> On 2/3/13 11:53 AM, j wrote:
>
> OT for a moment...
>
> My sewer line here is blocked, I've tracked it with great difficulty, by
> digging and looking. It takes a right into my backyard and then another
> right so it circles the house.
>
> So, I found the line is blocked between the sidewalk and the street. So,
> we dug down and struck... the new (and unused) gas line, 6" under that
> the crushed sewer pipe.
>
> I call the city at 3PM and they tell me to file a damage report with the
> gas company. However at 5PM someone from the city shows up and says the
> city will fix it by Sunday.
>
> Just now, someone came out and marked the water and sewer lines, the
> ones that I had no idea where. I've never seen anything like it, he had
> a collapsible metal divining rod and just walked across the pavement. It
> snapped to the side and he marked. In fact, he marked all the water and
> sewer lines, just like that, in no time. And it matches exactly.
>
> So, I am thoroughly impressed with the speed and psychic powers of this
> city!
>
> </OT>
>

Still OT.
If you can tell your sewer line story I can tell mine.

My drains were running slow, I tried drain cleaners, snaking from
in the house, nothing helped. I needed to bite the bullet, and spend a
weekend digging up the yard and installing a clean out so I could snake
the run to the road.
I got a 3 ft piece of 1/4" rod and poked the ground to locate and mark
where the sewer line ran. I started digging early Saturday morning, on
my third shovel I hit the pipe, on the fourth I saw a brass clean out plug.

Eureka!!

There is a clean out I didn't now about, and I hit it in 4 shovels. I
removed the plug (destroying it), went and rented the power snake
and bought a new plug. By noon I was done. If I had started digging a
foot closer to the road I would have missed the clean out and spent the
weekend digging.
The clean out is well marked, now.
Mikek

[j]

On 2/5/2013 4:44 PM, Morris Dovey wrote:
> On 2/5/13 11:42 AM, j wrote:
>

<snip>

>> So, I am thoroughly impressed with the speed and psychic powers of this
>> city!
>
> That /is/ impressive! Tell us the name of this exceptional city! :-)

Atlanta, Ga.

They were back out today marking the gas lines and the line into my
yard. Very colorful.

I used to get to get top notch garbage collection too, but I would leave
cold beers for them on hot days.

>
>> I'm struck by the amount off the shelf and cheap technology available.
>> And the Arduinos and the like to control them. Anything is possible,
>> parts you can't get you can send off to the 3D service bureau to get
>> made.
>
> See http://portabee3dprinter.com - at under $500 for the kit I think I'd
> prefer to be my own service bureau for all but precision parts,

Trouble is that there are multiple techniques depending on the material,
and that printer is limited in what in can print (as are all).

I can't find the bookmark now, but there is a service bureau that
charges by the CC (no setup fee) and prints in a variety of plastics,
stainless steel, silver, ceramic and other materials. Seemed cheap
enough for small parts.

Not that I wouldn't want to do it here.

but I
> think I'd be inclined to pay a bit more for the fully-assembled version.
> The additive technology is moving toward the point where we should
> (soon) be able to print circuit boards and houses.

I watched the cement "printer". Unbelievable.

>
>>>> I've altered my own solar air collector several times as money and
>>>> experience has allowed. The current geometry is too much depth, but
>>>> that
>>>> was largely determined by the geometry of the house and the jalousie
>>>> windows.
>
> I'm not sure you can actually have too much depth, but suspect that
> there's a point of diminishing returns. I'm fairly sure that with my
> (nominal) 8" panel depth, I hadn't reached it yet.

I test fired up one of the solar hot water collectors today for a while.
The box holds 4, ~ 80SF with each single collector ~ 2' x10'. I just
recycled water from a 5 gallon bucket.

It leveled off at ~ 120F, I think if the lines and bucket were insulated
it would do better. I'll run some more tests... With water it is easy
to calculate how many BTUs are produced, unless you are Rossi...

Cheers,
Jeff


>

[j]

On 2/6/2013 7:53 AM, amdx wrote:
> On 2/5/2013 11:42 AM, j wrote:
>> On 2/3/2013 6:17 PM, Morris Dovey wrote:
>>> On 2/3/13 11:53 AM, j wrote:
>>

<snip>

>>
> Still OT.
> If you can tell your sewer line story I can tell mine.
>
> My drains were running slow, I tried drain cleaners, snaking from
> in the house, nothing helped. I needed to bite the bullet, and spend a
> weekend digging up the yard and installing a clean out so I could snake
> the run to the road.
> I got a 3 ft piece of 1/4" rod and poked the ground to locate and mark
> where the sewer line ran. I started digging early Saturday morning, on
> my third shovel I hit the pipe, on the fourth I saw a brass clean out plug.
>
> Eureka!!

I like your luck better than mine!

Jeff

[Morris Dovey]

On 2/6/13 5:48 PM, j wrote:
> On 2/5/2013 4:44 PM, Morris Dovey wrote:

>> That /is/ impressive! Tell us the name of this exceptional city! :-)
>
> Atlanta, Ga.

I like that it's Atlanta because I was born there. :-]

> I can't find the bookmark now, but there is a service bureau that
> charges by the CC (no setup fee) and prints in a variety of plastics,
> stainless steel, silver, ceramic and other materials. Seemed cheap
> enough for small parts.

I'll STFW, but if/when you run across the bookmark, I'd /really/
appreciate an e-mail!

> I test fired up one of the solar hot water collectors today for a while.
> The box holds 4, ~ 80SF with each single collector ~ 2' x10'. I just
> recycled water from a 5 gallon bucket.
>
> It leveled off at ~ 120F, I think if the lines and bucket were insulated
> it would do better. I'll run some more tests... With water it is easy
> to calculate how many BTUs are produced, unless you are Rossi...

I think Rossi is trying to get all the recognition without disclosing
all that would be necessary for that to happen. Too bad for him - he's
making himself irrelevant. :-(

I built my one and only water heating panel forty years ago come May and
managed to scald myself three minutes after turning it to face the sun
on the first test. E-mail me if you'd be interested in trying out (yet)
another approach. :-)

[j]

On 2/6/2013 8:20 PM, Morris Dovey wrote:
> On 2/6/13 5:48 PM, j wrote:
>> On 2/5/2013 4:44 PM, Morris Dovey wrote:
>
>>> That /is/ impressive! Tell us the name of this exceptional city! :-)
>>
>> Atlanta, Ga.
>
> I like that it's Atlanta because I was born there. :-]

They are still at work. Yesterday a 3 man crew came out and looked it
over, the repair crew should be next. It's been raining here...

>
>> I can't find the bookmark now, but there is a service bureau that
>> charges by the CC (no setup fee) and prints in a variety of plastics,
>> stainless steel, silver, ceramic and other materials. Seemed cheap
>> enough for small parts.
>
> I'll STFW, but if/when you run across the bookmark, I'd /really/
> appreciate an e-mail!

The bookmark failed me, but searching history yielded the culprit, which
I originally found in a forum reference:

http://www.shapeways.com/materials

I have not used them,yet.

>
>> I test fired up one of the solar hot water collectors today for a while.
>> The box holds 4, ~ 80SF with each single collector ~ 2' x10'. I just
>> recycled water from a 5 gallon bucket.
>>
>> It leveled off at ~ 120F, I think if the lines and bucket were insulated
>> it would do better. I'll run some more tests... With water it is easy
>> to calculate how many BTUs are produced, unless you are Rossi...
>
> I think Rossi is trying to get all the recognition without disclosing
> all that would be necessary for that to happen. Too bad for him - he's
> making himself irrelevant. :-(
>
> I built my one and only water heating panel forty years ago come May and
> managed to scald myself three minutes after turning it to face the sun
> on the first test. E-mail me if you'd be interested in trying out (yet)
> another approach. :-)

Sure. I'll try to avoid the scalding though.

I ran another test a couple days ago. 5 gallons of water from 34F to
125F in the few hours before I stopped the test. I'm using a submersible
pond pump and I didn't want to damage the pump.

I'll try to get this plumbed into the house this week, and plug in the
other collectors. I'd like to be able to run it between 100F and 140F to
start off. Delta 40F at 100 gallons should give me 32K BTUs to get
through the night.

Jeff
>

[Morris Dovey]

On 2/13/13 7:12 AM, j wrote:
> On 2/6/2013 8:20 PM, Morris Dovey wrote:

>> I'll STFW, but if/when you run across the bookmark, I'd /really/
>> appreciate an e-mail!
>
> The bookmark failed me, but searching history yielded the culprit, which
> I originally found in a forum reference:
>
> http://www.shapeways.com/materials
>
> I have not used them,yet.

Thank you! Bookmarked them and just sent off an inquiry.

>> I built my one and only water heating panel forty years ago come May and
>> managed to scald myself three minutes after turning it to face the sun
>> on the first test. E-mail me if you'd be interested in trying out (yet)
>> another approach. :-)
>
> Sure. I'll try to avoid the scalding though.

Good plan! My test panel was 24wx30h and, since it was a tiny panel and
an overcast day, I decided to suck cold water up through the panel. In
the minute or so it took to do that, the water got quite a bit warmer
than I'd anticipated - it took weeks for my mouth to heal.

As time permits, I'll work up a drawing for a panel like that and let
you know when it's ready.

[Morris Dovey]

On 2/13/13 10:50 AM, Morris Dovey wrote:

> As time permits, I'll work up a drawing for a panel like that and let
> you know when it's ready.

Sketch is at http://www.iedu.com/tmp/SolarWaterHeater.png - it uses the
same fin approach as the air heater, and baseboard radiator (finned)
tubing in the heat exchanger. It's intended for vertical installation.

I'll leave it on-line through the weekend.

[j]

On 2/13/2013 4:42 PM, Morris Dovey wrote:> On 2/13/13 10:50 AM, Morris

Dovey wrote:
>
>> As time permits, I'll work up a drawing for a panel like that and let
>> you know when it's ready.
>
> Sketch is at http://www.iedu.com/tmp/SolarWaterHeater.png - it uses the
> same fin approach as the air heater, and baseboard radiator (finned)
> tubing in the heat exchanger. It's intended for vertical installation.
>
> I'll leave it on-line through the weekend.

Thanks, got it.

What's the cost of the feedstock for the fins?

Cheers,
Jeff
>

[mike]

On 2/13/2013 1:42 PM, Morris Dovey wrote:
> On 2/13/13 10:50 AM, Morris Dovey wrote:
>
>> As time permits, I'll work up a drawing for a panel like that and let
>> you know when it's ready.
>
> Sketch is at http://www.iedu.com/tmp/SolarWaterHeater.png - it uses the
> same fin approach as the air heater, and baseboard radiator (finned)
> tubing in the heat exchanger. It's intended for vertical installation.
>
> I'll leave it on-line through the weekend.
>

Can you explain how it works?
If I'm interpreting the drawing correctly, there's a barrier
between the fins and the heat exchanger.
Shouldn't the air be going across the exchanger fins??

[Morris Dovey]

I don't know - the pieces I used in my little panel were cut-offs from a
friend's remodeling job that the heating contractor hadn't hauled away.

[Morris Dovey]

You read it correctly - the front side heats the air and the back side
cools it. I played with it for a weekend and then retired it. The only
reason it got built at all was because I had the (free) materials and
was curious - and because I'd never soldered copper tubing and thought
it'd be a good learning experience.

[ It /was/ a good learning experience. I learned that an oxy-acetylene
torch was too hot for soldering copper tubing. :-) ]

From that (and more recent) experience I think there must have been a
strong air circulation inside the box - enough to overcome the friction
of all those fins. My interest back then was simply in seeing if my
conceptualizations matched up with the real world. I decided that they
did and moved on to more interesting projects.

Both panels went into the trash. :-)

[Morris Dovey]

Oops! I may not have understood the question. The front fins were cut
from (replaced) venetian blind slats - repainted flat black.

[Ecnerwal]

In article <kfho2c$l4l$1...@speranza.aioe.org>,

Morris Dovey <mrd...@iedu.com> wrote:
> [ It /was/ a good learning experience. I learned that an oxy-acetylene
> torch was too hot for soldering copper tubing. :-) ]

Nah, you just have to use the right flame. A long, soft (fuel-rich)
feather - you never get the cone involved, just the feather.
Comparatively expensive, but quite effective.

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

[Morris Dovey]

On 2/14/13 9:36 AM, Ecnerwal wrote:
> In article <kfho2c$l4l$1...@speranza.aioe.org>,
> Morris Dovey <mrd...@iedu.com> wrote:
>> [ It /was/ a good learning experience. I learned that an oxy-acetylene
>> torch was too hot for soldering copper tubing. :-) ]
>
> Nah, you just have to use the right flame. A long, soft (fuel-rich)
> feather - you never get the cone involved, just the feather.
> Comparatively expensive, but quite effective.

You shoulda seen my expression when I flash vaporized one of the thin
aluminum fins on the first piece of tubing!

The second try melted the end off a copper tube.

Then there was a whole sequence of tries with the tubing so hot that the
solder just ran off without wicking into the joint...

I wish I had a video - it'd be a hoot. A kid in his mid-20's with no
experience and no guidance. I did the reasonable thing, I went to the
hardware store and for suggestions - then finished the job with a
propane torch.

Well, it seems funny /now/. :-D

[Bob F]

I really appreciate you offering this info, even though I am in no position to
be able to put it to use. I'd love to use this technology,but live in cloudy
Seattle with several large poplar and other trees right on my south yard line,
so the low winter sun is pretty well blocked. I just wanted to say thanks. I
find it impressive what you have done. You have certainly been one of the more
generous participants in this forum.

[Morris Dovey]

On 2/16/13 12:27 PM, Bob F wrote:

> Morris Dovey wrote:

>> The page is at http://www.iedu.com/Solar/Panels
>
> I really appreciate you offering this info, even though I am in no position to
> be able to put it to use. I'd love to use this technology,but live in cloudy
> Seattle with several large poplar and other trees right on my south yard line,
> so the low winter sun is pretty well blocked. I just wanted to say thanks. I
> find it impressive what you have done. You have certainly been one of the more
> generous participants in this forum.

Thank you for your kind words - you're very welcome!

It would have been nice to have been able to produce a "silver bullet"
that'd work for everyone, and I'm certain that what I've managed to do
can be improved upon - but it's a start. I'm hoping that over the next
century architects, builders, and landscapers will transition to more
energy-efficient standards.

I'm not really all that generous. Think of it as payback to all those
who've gone before to lay the foundations I built on and to all those
who have been patient and helpful. Without them there'd be nothing to
share. :-)

[djh]

Morris, I really thank you on this. I have been thinking about building one
of these since the 70's Have not had the opportunity to yet, but am always
trying to learn more and more.
Wow.. on your presentation... Much interesting information in one place,,,
and available for all to review and learn from.
Thanks... what alt.energy.homepower is all about
kudos
Dave

"Morris Dovey" <mrd...@iedu.com> wrote in message
news:kdpnbh$gb6$1...@speranza.aioe.org...
>

[Morris Dovey]

On 5/21/13 9:29 PM, djh wrote:
> Morris, I really thank you on this. I have been thinking about building one
> of these since the 70's Have not had the opportunity to yet, but am always
> trying to learn more and more.
> Wow.. on your presentation... Much interesting information in one place,,,
> and available for all to review and learn from.
> Thanks... what alt.energy.homepower is all about

Dave...

You�re very welcome. It took a few years longer than I�d expected, but
then the result was also more satisfying than I�d expected. :-)

Kudos should be directed to some of the folks over at alt.solar.thermal
who patiently fielded a /lot/ of dumbass questions, fed me some really
helpful explanations and search criteria, and went out of their way to
help keep me on productive paths. Whatever accomplishment there might
be, they share in it.

A Kiwi friend has agreed to produce an MP4 assembly animation - and I�ll
add that to the web page as soon as he�s able to deliver.

There are a couple of (convenience) improvements that�ll have to wait
for completion of the current LENR/MHD project, but they�re intended to
improve high-rise installations and shouldn�t affect performance.

--
Morris Dovey
http://www.iedu.com/Solar/

http://www.facebook.com/MorrisDovey