Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland

THOMAS CLEVELAND, wrote the following at or about 6/7/2007 1:01 PM:
Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Unless it's a sealed system, I'd be leery of a gas unit in a workshop.

I installed one of these (a Dayton Electric G73 electric ceiling heater)
in my 24'x16' shop two years ago and have never regretted the decision
for a second.

It keeps the well insulated shop above 45 degrees year around very
economically and when I want to work out there in the dead of winter,
brings the shop up to around 70 degrees in about 12-17 minutes. I ran a
separate 30amp line for it (have a 100 amp panel in the garage/shop).

http://www.dealtime.com/xPF-G73

THOMAS CLEVELAND wrote:
Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

I don't know what a "hot dog" heater is (by that name at least) but I'll
echo Confused's concern -- gas is ok in a shop but should definitely be
external draft model, not internal. Higher initial cost, but for a
small area wouldn't be exorbitantly different and the peace of mind is
priceless...

Only way I'd relent is if this is to be an "all-Neandertool" shop and no
plan for finishing--in that case the dust and/or fumes generation could
be minimal enough as to not be a major concern.

--

dpb wrote in :

THOMAS CLEVELAND wrote:
Hello
I'm building a new but small shop, it will be 8' X 10' how ever
living
in the north east it will get cold up here, it will be insulated,
tyvec
wrapped and sided, have ac for the summer, but need heat for the
winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and
run
on propane, any input will be gladly welcomed.

I don't know what a "hot dog" heater is (by that name at least) but
I'll
echo Confused's concern -- gas is ok in a shop but should definitely
be
external draft model, not internal. Higher initial cost, but for a
small area wouldn't be exorbitantly different and the peace of mind is
priceless...

Only way I'd relent is if this is to be an "all-Neandertool" shop and
no
plan for finishing--in that case the dust and/or fumes generation
could
be minimal enough as to not be a major concern.

--



I may not be the same as the rest of you folks. OK, I'm not. But what
I planned to do in my shop when I started 6 or 8 years ago is different
than what I do today.

Make no inflexible choices, particularly where safety is concerned.

I started out with power tools, but I don't use them nearly as much as I
used to. At least, it seems that way. Maybe it's just less dramatic
than it once was.

Get a good, externally vented heater. This isn't an open construction
site we're discussing here. Fumes accumulate.

Patriarch

On Jun 7, 2:38 pm, Patriarch wrote:

SNIP of good thoughts

Get a good, externally vented heater. This isn't an open construction
site we're discussing here. Fumes accumulate.

Absolutely couldn't agree more. Even radiant heaters can generate a
spark by igniting a small piece of sawdust thrown in the air that
circulates close to the elements, and on the better ones that put out
some real heat, I have seen little sparklets generated when heavy
sanding appears.

It wouldn't take much for all manner of fumes to accumulate in a shop
that small. No would it take much for noxious gasses to build up
DEPENDING on the type of heater you get as the years go by and the
machine becomes less efficient at burning its fuel.

Robert

On Thu, 7 Jun 2007 14:01:08 -0400, (THOMAS
CLEVELAND) wrote:

Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland






I just use a "construction" heater hung from my ceiling- takes up
little space and provides plenty of heat- especially if the shop is
small and insulated.

Runs on 220, have had one for 8 years, no problems at all. Live in
central BC so the heater gets plenty of use.

Mick

THOMAS CLEVELAND wrote:
Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland


Never having been in the NE, it still seems to me that for a small "insulated,
tyvec wrapped and sided" 8x10 shop like yours practically any small electric
space heater would do the job.

Wayne

THOMAS CLEVELAND wrote:
| Hello
| I'm building a new but small shop, it will be 8' X 10' how ever
| living in the north east it will get cold up here, it will be
| insulated, tyvec wrapped and sided, have ac for the summer, but
| need heat for the winter, I saw and like the "Hot Dog" heaters that
| hang from the ceiling and run on propane, any input will be gladly
| welcomed.

You might find the link below if interest - a somewhat larger shop in
my area that's solar heated.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/SC_Madison.html

Morris Dovey, wrote the following at or about 6/7/2007 5:27 PM:
THOMAS CLEVELAND wrote:
| Hello
| I'm building a new but small shop, it will be 8' X 10' how ever
| living in the north east it will get cold up here, it will be
| insulated, tyvec wrapped and sided, have ac for the summer, but
| need heat for the winter, I saw and like the "Hot Dog" heaters that
| hang from the ceiling and run on propane, any input will be gladly
| welcomed.

You might find the link below if interest - a somewhat larger shop in
my area that's solar heated.

Morris, forgive me for asking if you've explained this previously but
what's the square footage of that shop, the ceiling height and what do
you consider to be a "comfortable daytime temperature" in the winter
months for that particular application?

Also, that makeup heater looks to be just a tad bigger than the one I
have. What is it, about a 7500 watt?

That is just such a great looking installation and shop area and to
think, once installed and paid for, it's nearly maintenance free and
starts paying back immediately.

Were I building/rebuilding my shop, we'd be talking for sureg.

Great work!

mick wrote:
On Thu, 7 Jun 2007 14:01:08 -0400, (THOMAS
CLEVELAND) wrote:

Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland

Hi Thomas. I used the smallest Hot Dog heater in my old 650 sq ft. shop.
In your smaller shop, I think you would find it overwhelming. Lots of
btu's, lots of air movement - too much of both in 80 sq. ft would be my
guess.

Rick

My shop is 12 x 24 metal siding and roof and no insulation, located in
southern MN.

When outside temperature is below 35 degrees I abandon it and do other
things.

But warmer than that, I bundle up good (insulated pants, multiple jacket
layers, and stocking cap) and go out. I have a small propane radiant
heater (the round type). I hung 2 250 watt heat lamps over the bench, and
two over the lathe.

(By the way, I tested the heater by blowing a handful of sawdust into it
when it was running. Just a mini 4th of July as dust grains flared into
sparks).

I've been amazed how much I can do in that environment, without my hands
getting TOO cold. Of course any gluing, or finishing has to be moved into a
heated location, as well as anything that has water.

Probably doesn't fit your situation.

Old Guy
Luxuriating in warmth these days.
"THOMAS CLEVELAND" wrote in message
...
Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland

With a shop that is a mere 8' x 10' then, unless you are a person who
would prefer to work wood on a beach in the Bahamas, you'll do just fine
with a quartz radiant heater as you will not be moving around very much
in such a relatively confined space. The quartz heater is grand for
heating a static area of the workbench where hand/power tool work is
done. That, and a quilted shirt on the coldest of days in winter, will
serve you well, IMO, as any sort of open flame is just asking for
trouble. A blast of human/compressed air on the heater to dispel any
accumulated dust or whatever is all that is needed prior to starting the
heater (and then only if you have a really dusty shop).

J.

(working in one half of a two-car garage in NY for nearly 15 years)



THOMAS CLEVELAND wrote:
Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland

Thu, Jun 7, 2007, 2:01pm (THOMAS*CLEVELAND) doth
claimeth:
Hello
****I'm building a new but small shop, it will be 8' X 10' how
ever living in the north east it will get cold up here, it will be
insulated, tyvec wrapped and sided, have ac for the summer, but need
heat for the winter, I saw and like the "Hot Dog" heaters that hang from
the ceiling and run on propane, any input will be gladly welcomed.

You're building it, eh? I wonder then if you realize just how
small a 8'X10' shop is going to be, especially after you start putting
tools and all in. Unless yoo maybe don[t plan on doing woodworking -
you didnt say. My shop is 8'X12' only because that was all I had money
to spare for at the time, a choice of something, or nothing. It's
uninsulated, but even so, a small electric heater, with a fan, warms it
up nicely. I tried one of those electric oil-filled radiator type
heaters; worked well enough, but took quite a bit longer than I cared
for to get the heat up. If I'd been willing to turn it on, then go back
out a 2-3 hours later it should hve served well, but I prefer something
a bit faster. The little electric ceramic type heater I have out there
now serves well enough.

I'd like to know what you plan on doing in such a small shop. That
is if you ever come back, so many seem to ask a question, then never
show up again.



JOAT
If a man does his best, what else is there?
- General George S. Patton

On Thu, 7 Jun 2007 14:01:08 -0400, (THOMAS
CLEVELAND) wrote:

I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

You might consider one of the "motel type" heater/cooling units. It
can be mounted through the wall or in a window and if you have power
for a window unit, the same will run the heat.

Mike O.

Unquestionably Confused wrote:
| Morris Dovey, wrote the following at or about 6/7/2007 5:27 PM:
|| THOMAS CLEVELAND wrote:
||| Hello
||| I'm building a new but small shop, it will be 8' X 10' how ever
||| living in the north east it will get cold up here, it will be
||| insulated, tyvec wrapped and sided, have ac for the summer, but
||| need heat for the winter, I saw and like the "Hot Dog" heaters
||| that hang from the ceiling and run on propane, any input will be
||| gladly welcomed.
||
|| You might find the link below of interest - a somewhat larger shop
|| in my area that's solar heated.
|
| Morris, forgive me for asking if you've explained this previously
| but what's the square footage of that shop, the ceiling height and
| what do you consider to be a "comfortable daytime temperature" in
| the winter months for that particular application?

That shop is 30' x 40' - so floor space will be a bit less than 1200
sq ft. A comfortable daytime temperature is anything in excess of 72F.
If there's a run of especially sunny days, the owner will probably
need to open windows during the day to keep the temperature in the
70's.

| Also, that makeup heater looks to be just a tad bigger than the one
| I have. What is it, about a 7500 watt?

I don't remember - I think he told me that it's a 20kBtu heater. Food
for thought: in the solar context, his ceiling fan will be even more
important than his unit heater.

| That is just such a great looking installation and shop area and to
| think, once installed and paid for, it's nearly maintenance free and
| starts paying back immediately.
|
| Were I building/rebuilding my shop, we'd be talking for sureg.

Always glad to do that - on the other hand, one of the purposes of
that web page is to demonstrate the total absence of magic. On the
third hand, there's more to the design than meets the eye. g

If you're inclined to go the DIY route, there're links on the DeSoto
Solar home page that provide some essential "getting started"
information. (Some of the info is specific to the USA, and I'd be
pleased to be able to make the same information available for other
parts of the world.)

| Great work!

Thanks. It's interesting to wrestle with the trade-offs to deliver a
maximum of heat for a minimum of cost - in a panel intended to serve
for the lifetime of the structure. These panels were the best I'd ever
produced - but provided info leading to _three_ low-cost design
improvements that'll make these inferior to all my future panels.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/SC_Madison.html

On Jun 7, 2:01 pm, (THOMAS CLEVELAND) wrote:
Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland

My insulated, detached, 2 car garage/shop in Detroit heats up on a
zero degree day in about half an hour. I use a little electric heater
that runs on 220, from Lowes or Home Depot, called "The Hot One" (made
by Cadet, I think). I like it a lot - but I think they make smaller
units more appropriate for your space.

Subject

For a shop in the NE, used on an intermittent basis, the MOST
IMPORTANT thing will be a good insulation job along with radiant heating.

Electric, operating at 240VAC, would be my choice.

Lew

With a shop that is a mere 8' x 10' then, unless you are a person who
would prefer to work wood on a beach in the Bahamas, you'll do just fine
with a quartz radiant heater as you will not be moving around very much
in such a relatively confined space.

I'll echo this, based on my own experience. I have a basement shop in
upstate NY that's about 8x12 or so, and a quartz radiant heater is
just fine. Of course in the basement it never gets below 40-45F, but
your well-insulated shop should do OK. With the limited floor space,
I often hang my heater on the (cement) wall, but if I were buying a
new one, there are some ceiling-mount heaters by Marvin - I believe
Lee Valley sells at least one model with a halogen light in it. Even
my ceiling space is filling up with stuff, so if you can get a light
and heater in one, I'd consider that a valuable use of space.
Good luck,
Andy

mick wrote:
On Thu, 7 Jun 2007 14:01:08 -0400, (THOMAS
CLEVELAND) wrote:

Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland






I just use a "construction" heater hung from my ceiling- takes up
little space and provides plenty of heat- especially if the shop is
small and insulated.

Runs on 220, have had one for 8 years, no problems at all. Live in
central BC so the heater gets plenty of use.

Mick

I used the same type of heater in my 12 x 20 shed. I lived in the shed
while I was building my house. Slept out there when temps. got down
below -40 deg. Mild Manitoba winter night.

THOMAS CLEVELAND wrote:

Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.


My shop is 11x14 and not as well insulated as yours. A simple electric heater
keeps it at 40 all night. Before breakfast I go out and turn it up. Takes
about an hour to raise the temperature to 60 if the outdoor temp is above 20.
If it's colder than that I don't want to go out anyway :-).

BTW, when I'm in the shop the heater sits anywhere out of the way. When I'm
not it sits on the cast iron tablesaw top. It's always plugged into a GFCI
outlet. That way I feel it's pretty safe.

--
It's turtles, all the way down

Morris Dovey, wrote the following at or about 6/7/2007 9:20 PM:
That shop is 30' x 40' - so floor space will be a bit less than 1200
sq ft. A comfortable daytime temperature is anything in excess of 72F.
If there's a run of especially sunny days, the owner will probably
need to open windows during the day to keep the temperature in the
70's.

Any idea how impressive that is to us dorks who are paying into the
grid?g That's incredible, Morris. If you don't mind saying, what was
the cost of those "Panels of Madison County."

I don't remember - I think he told me that it's a 20kBtu heater. Food
for thought: in the solar context, his ceiling fan will be even more
important than his unit heater.

That's close to what I use in my shop. I think the high output mode on
the Dayton is 17.5kBTU

I can understand the necessity for the ceiling fan as we have cathedral
ceilings in the kitchen and family room. Certainly helps to balance the
heat from the wood stove out there.

Always glad to do that - on the other hand, one of the purposes of
that web page is to demonstrate the total absence of magic. On the
third hand, there's more to the design than meets the eye. g

It certainly does make a point. No magic, but the output is way more
than what I ever would have guessed for those two panels in that sized
structure.

Unquestionably Confused wrote:
| Morris Dovey, wrote the following at or about 6/7/2007 9:20 PM:

|| That shop is 30' x 40' - so floor space will be a bit less than
|| 1200 sq ft. A comfortable daytime temperature is anything in
|| excess of 72F. If there's a run of especially sunny days, the
|| owner will probably need to open windows during the day to keep
|| the temperature in the 70's.
|
| Any idea how impressive that is to us dorks who are paying into the
| grid?g That's incredible, Morris. If you don't mind saying,
| what was the cost of those "Panels of Madison County."

It's not a "Bad Thing" to pay into the grid - it's only bad to pay in
more than is needful. Solar energy isn't a panacea, but in some
applications it does offer solid economic advantage.

I don't mind saying - but I say it at
http://www.iedu.com/DeSoto/sc_prices.html so no one finds an old price
in the archive and gets PO'd because I ask 'em to write a check for
more than what they'd found.

The sun does deliver an impressive amount of energy to our little
planet. I've knocked myself out to produce a design to capture
everything from low-frequency EM through UV, and it seems to pay off
(most notably in the IR range). If you haven't seen the plot of solar
energy distribution by wavelength, you might find
http://www.iedu.com/DeSoto/Absorber.html interesting.

|| I don't remember - I think he told me that it's a 20kBtu heater.
|| Food for thought: in the solar context, his ceiling fan will be
|| even more important than his unit heater.
|
| That's close to what I use in my shop. I think the high output
| mode on the Dayton is 17.5kBTU
|
| I can understand the necessity for the ceiling fan as we have
| cathedral ceilings in the kitchen and family room. Certainly helps
| to balance the heat from the wood stove out there.

In this shop, the insulated 6" concrete slab acts as a big thermal
"flywheel". Since warmed air "wants" to stay up near the ceiling, the
fan is necessary to shoot it down to warm the floor. When the sun sets
and the solar panel shuts down, the heat stored in the floor radiates
as IR to extend the daily comfort period and prevent the shop
temperature from dropping anywhere near the freezing range overnight.

|| Always glad to do that - on the other hand, one of the purposes of
|| that web page is to demonstrate the total absence of magic. On the
|| third hand, there's more to the design than meets the eye. g
|
| It certainly does make a point. No magic, but the output is way
| more than what I ever would have guessed for those two panels in
| that sized structure.

The structure is well-sealed and well-insulated, which is important
regardless of heating system. If you stand a full arm's length away
from these panels at noon on the winter solstice, these totally
passive panels will blow your hair back - if you have hair vbg

It's important to panel efficiency to get the heat out of the panel as
quickly as possible. By designing to maximimize capture bandwidth and
to maximize the volume of air flowing through the panel, the panel
operates at a lower temperature and delivers more heat. Operating the
panel at a lower temperature reduces the black body (IR) radiation
back through the glazing, and lowers conductive losses through the
panel body. It's a balancing act, but as you home in on the balance
point, panel performance does seem to peak spectacularly.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

Morris Dovey, wrote the following at or about 6/8/2007 6:07 PM:
I don't mind saying - but I say it at
http://www.iedu.com/DeSoto/sc_prices.html so no one finds an old price
in the archive and gets PO'd because I ask 'em to write a check for
more than what they'd found.

Sorry about that, found the price list after the question went out.
Damn! ~$3200 for a unit to heat that place. Let's see now... Gotta be
what? $2000 for a decent FANG unit, ductwork and install and you get
to keep paying and paying to keep it fueled and running vs what solar
offers. Damn that's a hard one - not!g

In this shop, the insulated 6" concrete slab acts as a big thermal
"flywheel". Since warmed air "wants" to stay up near the ceiling, the
fan is necessary to shoot it down to warm the floor. When the sun sets
and the solar panel shuts down, the heat stored in the floor radiates
as IR to extend the daily comfort period and prevent the shop
temperature from dropping anywhere near the freezing range overnight.

Again, I guess I'm somewhat surprised that the concrete (insulated or
not) comes into play that much. Would expect it, I guess, from basking
in the direct sunlight behind a wall of windows, etc. but not so much
with the air above circulating over it.


The structure is well-sealed and well-insulated, which is important
regardless of heating system. If you stand a full arm's length away
from these panels at noon on the winter solstice, these totally
passive panels will blow your hair back - if you have hair vbg

Yeah, I still have enough to blow around with a convertible and probably
with one of your panels as well. What really blows me away though is
your system. Thanks for sharing your knowledge.



It's important to panel efficiency to get the heat out of the panel as
quickly as possible. By designing to maximimize capture bandwidth and
to maximize the volume of air flowing through the panel, the panel
operates at a lower temperature and delivers more heat. Operating the
panel at a lower temperature reduces the black body (IR) radiation
back through the glazing, and lowers conductive losses through the
panel body. It's a balancing act, but as you home in on the balance
point, panel performance does seem to peak spectacularly.

Okay, that explains why the high efficiency panels are "more better"
though they are operating at 140 degrees vs the discontinued economy
panels that were running at 160 degrees.

Lot's of good replies so far.
MY .02:
Do NOT use any heater that runs on propane, fuel oil, etc that vent into
the shop. Safety aside, they ALL generate a lot of water, which will
rust everything.
Your main goal is to warm yourself, but right behind it is to
produce a non-condensing environment for you shop's equipment. That
requires some heat above ambient all the time. When your equipment is
cold and the air warms up, water condenses out of the air onto those
cold surfaces and you get rust.

No one has mentioned warming the floor. I don't know about you, but my
feet and lower legs are my main problem when standing in a shop. DO
get a heater that has a blower so the floor area can be warmed, not just
the top 4 feet of the shop.
I use counter-flow (extermally vented) propane furnaces in my shops
and they are great. I work several days a month in a shop that has one
of those ceiling mounted heaters and it is miserable, as far as I am
concerned. It is often 95 degrees 7 feet off the floor and 50 degress
or less 2 feet off the floor.

Pete Stanaitis
---------------------------

THOMAS CLEVELAND wrote:

Hello
I'm building a new but small shop, it will be 8' X 10' how ever living
in the north east it will get cold up here, it will be insulated, tyvec
wrapped and sided, have ac for the summer, but need heat for the winter,
I saw and like the "Hot Dog" heaters that hang from the ceiling and run
on propane, any input will be gladly welcomed.

Cheers,
Thomas Cleveland

Unquestionably Confused wrote:
| Morris Dovey, wrote the following at or about 6/8/2007 6:07 PM:

|| In this shop, the insulated 6" concrete slab acts as a big thermal
|| "flywheel". Since warmed air "wants" to stay up near the ceiling,
|| the fan is necessary to shoot it down to warm the floor. When the
|| sun sets and the solar panel shuts down, the heat stored in the
|| floor radiates as IR to extend the daily comfort period and
|| prevent the shop temperature from dropping anywhere near the
|| freezing range overnight.
|
| Again, I guess I'm somewhat surprised that the concrete (insulated
| or not) comes into play that much. Would expect it, I guess, from
| basking in the direct sunlight behind a wall of windows, etc. but
| not so much with the air above circulating over it.

Normally (without the fan) the slab would not play such an important
role. The ceiling fan provides a whole collection of benefits, and
it's difficult to say that any one of them is more important than the
others.

By pushing the warm air away from the ceiling, it helps to reduce
conductive losses through the ceiling.

By mixing the warm air with the cooler air below it reduces
stratification and evens out the heat distribution throughout the shop
to make the whole more comfortable.

The continuous flow of warm air on the insulated slab warms raises its
temperature (stores energy in it) so that the it will begin giving up
its heat to the air as soon as the air temperature drops below that of
the slab. If the slab were left cold, it would still take some energy
from the air that touched it, but it would warm less and might
continue absorbing heat well beyond the point where the air felt
chilly.

|| It's important to panel efficiency to get the heat out of the
|| panel as quickly as possible. By designing to maximimize capture
|| bandwidth and to maximize the volume of air flowing through the
|| panel, the panel operates at a lower temperature and delivers more
|| heat. Operating the panel at a lower temperature reduces the black
|| body (IR) radiation back through the glazing, and lowers
|| conductive losses through the panel body. It's a balancing act,
|| but as you home in on the balance point, panel performance does
|| seem to peak spectacularly.
|
| Okay, that explains why the high efficiency panels are "more better"
| though they are operating at 140 degrees vs the discontinued economy
| panels that were running at 160 degrees.

Exactly! The concept you've grasped is of the utmost importance - that
heat (energy) and temperature are _not_ synonyms.

My current aim is to lower that 140F to 120F for a 6'-tall panel
without major cost increase. The Madison County installation won't
quite make it but I'm getting closer with every design iteration.
Interestingly, I'm not sure that achieving that goal will necessarily
produce a more efficient /system/.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/SC_Madison.html

spaco wrote:

| No one has mentioned warming the floor. I don't know about you,
| but my feet and lower legs are my main problem when standing in a
| shop. DO get a heater that has a blower so the floor area can be
| warmed, not just the top 4 feet of the shop.

Pete...

One solution to this problem is to install an inexpensive ceiling fan
(the "ceiling huggers" are best) and run it at low speed to use the
warm air near the ceiling to warm the floor. Not only will it provide
greater comfort, but it'll allow you to use less fuel.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

Morris Dovey wrote:

My current aim is to lower that 140F to 120F for a 6'-tall panel
without major cost increase. The Madison County installation won't
quite make it but I'm getting closer with every design iteration.
Interestingly, I'm not sure that achieving that goal will necessarily
produce a more efficient /system/.

How about a hybrid system? Would not adding, say, a low-cost
(operation) axial/muffin fan with a rheostat allow you to tweak the
internal temperature?

In your scheme of things that'd be cheating, I know, but... I'm just
thinking aloud here. Even from a testing/design aspect you'd at least
be able to see if the 120F would be more efficient, no?

Unquestionably Confused wrote:
| Morris Dovey wrote:

|| My current aim is to lower that 140F to 120F for a 6'-tall panel
|| without major cost increase. The Madison County installation won't
|| quite make it but I'm getting closer with every design iteration.
|| Interestingly, I'm not sure that achieving that goal will
|| necessarily produce a more efficient /system/.
|
| How about a hybrid system? Would not adding, say, a low-cost
| (operation) axial/muffin fan with a rheostat allow you to tweak the
| internal temperature?
|
| In your scheme of things that'd be cheating, I know, but... I'm
| just thinking aloud here. Even from a testing/design aspect you'd
| at least be able to see if the 120F would be more efficient, no?

I don't consider fans cheating - but insist that they not actually
/impede/ operation of the panel.

At this point, the best of the axial/muffin fans (I have a small
collection of not-so-cheap fans of a variety of types brought in by
well-meaning friends) and all except the very largest (1/2 HP and up)
act more as obstructions than enhancements to the airflow - even when
running full-bore.

Although it's not an issue involving "cheating", I really do prefer
the absolutely silent operation of the purely convectional operation.

I can boost the natural convection (lower temperature) by
"streamlining" the interior plenums - rounding all the interior angles
in the plenums, providing still smoother internal surfaces, etc. - but
from where the design is today, all of these represent significant
increases in labor and/or material costs.

The system question is: "What is the optimal discharge temperature
that provides a comfortable environment for humans yet allows maximum
_coincidental_ heat storage in a typical installation?"

The question contains a hidden twist in that excess heat can be
discarded without impacting operational costs in any way - with an
additional consideration that the discard mechanism can be used to
control humidity.

It's the "typical installation" that's the unknown here. I don't need
fans - what I really need is a variety of solar-heatable /structures/
to test. :-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/