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Posted by Morris Dovey on December 11, 2010, 9:45 pm
 
On 12/11/2010 2:43 PM, Frontier wrote:

Very possibly it was a gentleman in Sarnia, Ontario.


Solar or no solar, the first order of business should definitely be to
get rid of air leaks and to insulate as well as you can.


The amount of energy available is determined by the capture area. Use
all of it that you can. The twinwall polycarbonate that I used was
manufactured for roofing applications, and is used in my area for at
least some greenhouses.

I'm all for recycling, but there are times when "free" and "cheap"
actually end up costing more.

Polygal(tm) twinwall panels are available in lengths that'll do the job.
I think they're made in NC. There are probably other manufacturers
making similar products - check with your nearest large plastics
distributors for sizes and prices.

I used aluminum ribbon - see

   http://www.iedu.com/DeSoto/Misc/Coil (320x240).jpg

for a look - with really good results. The downside of the ribbon was
that I had to order a minimum 25 km of the stuff.

The problems with cans are (1) they don't allow an adequate airflow
(which makes for unacceptably high temperatures in the front of the
panel, which maximizes heat losses), and (2) any method of painting them
(other than careful powder-coating) results in an insulating layer. For
folks who're only going to build one or two panels, I usually recommend
1" venetian blind slats with a black factory powder-coat.


I've been encouraging people to design and build their own from the
start. I've been frustrated that most of those just wanted to copy mine
when there's such a huge need for more ideas and exploration. My
developments were limited (severely) by available budget.

A good source of DIY info is Gary Reysa's site at

   http://www.builditsolar.com

and it's worth noting that Gary has been willing to try his own ideas
and has had some measure of success. I think my panels are better, but
while Gary held a DIY focus, my interest was in something suitable for
mass-production, commercial distribution, and that could be dropped into
a rough opening more or less like a manufactured window unit.


Don't stay away so long this time - and please share what you do and
learn from your experience with the rest of us!


Lucky you! You've got mills all around you and at least one of the
glazing manufacturers is reasonably close - pretty country, too!

--
Morris Dovey
http://www.iedu.com/DeSoto/
PGP Key ID EBB1E70E


Posted by Frontier on December 11, 2010, 11:21 pm
 
Morris,
Thanks for all the information. I pretty much had gotten what you're saying
with regards to innovation and so on from your posts I read previously and
your reverse engineering page on your site now. I have to admit, my work in
construction and the wood shop are so overwhelmingly busy right now that I
was/am looking for a bit of a guide to doing something that would work
rather than trying to re-invent the wheel. I really enjoy building
prototypes and working out designs and so on when I have time but it is what
I am doing all day and I simply don't have many more hours (or ounces of
energy) to add something else to the mix.

I am really not motivated by saving gas or money on this deal either its
just that living off grid, seeing these two openings that are going to be
closed up looks to be a prime opportunity to do "something" with them other
than wall them in. Additionally our shop is right on the main street and
seeing these panels would likely cause some buzz but I hate to think of it
that way as someone will likely walk in wanting us to build them some and I
have enough things to build. It would however be nice exposure for solar
heating in general.

I will do some reading on the site you posted. At a quick glance you may
have also posted that information as it looks a little familiar.

Agreed with regards to closing up/sealing up however its not going to be a
quick process in this building as I don't have the time to re-wire the
entire place in one shot and I am not willing to bury much of the work the
old "firemen" did when they put up this building. It's a wonder the fire
station didn't burn down.

I will look to some sources for aluminum and see what I can come up with. At
present I am thinking of a box unit made of 1/2" MDO ply and now will have
to come up with something for the collector but it shouldn't be a major
issue. I will get to reading.

--
Mark


Posted by Morris Dovey on December 12, 2010, 6:08 pm
 On 12/11/2010 5:21 PM, Frontier wrote:

I'm not much of a wordsmith and am inclined to be blunt when I'm
frustrated. There are a lot of smart people in the world - and it makes
me at a little crazy when people won't follow through on their /own/ ideas.

The zinger with solar panels is that, in spite of keeping warm in the
sun for millions of years, the technology hasn't been developed to the
point where we're ready to /engineer/ good solutions.


I hear you - but in this field we haven't really managed to get beyond
the point of recognizing that something without corners rolls better
than something with corners - but we still haven't figured out that our
proto-axle needs to attach at the very center of our proto-wheel. :)

If we want to heat air with sunshine, then we need to know about at
least sunshine and heat and air, and it doesn't work to say that because
we can't see them there's nothing to know.

By way of example, when air is heated its viscosity increases - a
behavior opposite that of familiar substances like honey. When air is
heated by coming in contact with a hot surface, it gets "gooier" and
sticks to that surface and resists flowing - and then the "stuck" air
forms an insulating layer over the surface. That's one of the reasons
why the old pop/beer can designs work so poorly.


Welcome to the club!


Well, people will take notice - and even if you don't want to get into
the business of building panels, it probably wouldn't hurt to be seen as
someone who can "think outside the box" - and that perception might help
to attract the business you /do/ want...


Gary's a good guy. He may lurk here. I know he at least occasionally
posts to news:alt.solar.thermal - and he's responded in a friendly,
helpful way whenever I've e-mailed him questions/comments.


I'm sympathetic - I can't remember a renovation project where, at some
point, I didn't have the thought that starting over from scratch might
have been easier. :)


I think the big box (Lowes, Home Depot, etc) stores all sell aluminum
blinds and, believe it or not, black is one of the standard colors. You
might need to wait a week for them to get stock - but you can order the
width you want.

I built two panels with 3/4" MDO (Rob in Sarnia has one of them) and
decided afterward that I liked 1x boards better. The MDO seemed too
"bendy" and SPF/poplar boards had better thermal characteristics. If I'd
had a good SYP source, I think I might have liked 1x8 SYP for the box frame.

I'm still amazed that someone would pour a less than 6" slab to support
fire trucks...

--
Morris Dovey
http://www.iedu.com/DeSoto/
PGP Key ID EBB1E70E


Posted by Frontier on December 12, 2010, 9:35 pm
 
Well, this is a very country/rural area to say the least and what often
shocks me in places like this is things are either grossly over engineered
or horrendously under engineered. You see this all the time in old farm
buildings or homes where something was slapped together out of parts or junk
wood because the people either didn't have the money or were to cheap to buy
what they needed but then they put 52 nails in a joint where two 2x4s come
together so that its "nailed good". They go way over the top where it really
doesn't matter and fall far short where it does.

This floor is actually quite comical because we have had to cut it to form
trough's for ducting. They threw anything and everything in the slab to act
as rebar. Old telephone pole guy wires coiled around willie nilly, rod,
pieces of pipe, and so on. Then it looks that they put large rebar on top of
the pour and worked them down to the wet mix so now you have your mat in the
upper third of the slab rather than in the lower third where it should be.
This of course adds virtually no strength and then causes the thin layer of
concrete over top of the mat to break/flake off. So in many places the wear
layer of the slab has flaked away exposing a #6 bar an inch below the
surface.

How it held up as long as it did I don't know but we have heavy clay soils
here so they have extremely high compressive strength and that is likely
what saved them.

The rest of the building is better but similar. It was put together with
volunteer labor on donated land and I am sure on a shoe string budget so
they did the best they could with what they had.

Even with all that we have 4000sq' under roof for a very small fraction of
what it would cost to build a new building so I have to count my blessings.

Thanks again for the info and nice to talk,
Mark





Posted by z on December 13, 2010, 3:03 am
 

Yeah I know what you are saying.  Our volunteer fire department has
similar issues.  We still had a tender that was a 1956 international not
too long ago, and a lot of times those buildings were just put up by
volunteers with zero funding.  And then you always have the guy who's the
'chief' who -- if you are lucky is a very good fire fighter with
experience etc -- or it could just be the loudest dude in town.

Our town is about 400 people ish and the fire department was set up kind
of like you are talking about.  In the past 10 years or so it's improved
A LOT.  They also got some home land security money for equipment and the
new chief isn't an idiot.

But the fire house is just about like the building you describe (minus
the bad floor -- they must have had a buddy with a cement truck when
built back in 1930-1940 some time.  The walls though.. it'll blow your
cap off in there with the doors closed if the winds are high :)

It's never that cold here though on the oregon coast, so heating the
place isn't that important.  I don't even think we have heat in there.  
It's a truck and equipment shed/barn more or less.

Also, since it was a public building a lot of times they could get away
with not following any kind of code, especially in the old days.

Even now our old red brick school would be totally illegal as a shopping
mall or whatnot due to lack of earth quake proofing, but it's totally
fine for 3rd graders.  

good luck with your project

-zachary in Oregon


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