Awl--

After much thermodynamic agonizing and wasted BTUs, and a little help on
alt.hvac, alt.home.repair, "mini-splits" or ductless A/C's seem to be the
way to go. Klimaire in FL makes a charged 24,000 btu unit for $799 + $160
s&h. Oh yeah, it's also a heat pump!
You need a techie to vacuum/connect it, but I'm told if you (me) do all the
mechanical setup, this can be a relatively nominal, uh, charge.

PC Richards et al don't seem to supply these type units.

Any other leads/sources/experiences? Any tips?
--
Mr. P.V.'d
formerly Droll Troll

While we're on the subject...


My shop is a 4000 square foot metal building with just a little insulation.
I've got 2 residential air conditioning units that keeps it bearable, but
not comfortable in our Missouri summers. I've heard that our humidity is too
high to use an evaporitve cooler in this area effectively, but I've always
wondered how one of those would do in a shop that has two central air units
running non stop. Would it actually add any cooling? Would it cause my
equipment to rust? It would sure be cheaper to operate than a 3rd AC unit.

Don't know about evaporative cooling. Would that be *inside* the shop, or a
water tower-type deal outside the shop?

Direct sun on roofs is a killer, and likely much worserer in a metal
building.
I think I've heard of insulating paints, that might help.

But *any* kind of air gap would help enormously to reduce the load. If you
have a flat roof, any kind of skin or sheathing a few inches off the top (a
foot or so would be better) would help. I scattered milk crates over an
exposed flat tar roof. Helped!!

An air gap *inside* the building, w/ exhaust forced air, would help also. A
hung ceiling would do very well. Could cut your A/C costs proly in half.
Also reduces the volume requiring A/C/heat.
If you hung a ceiling, in the winter/cold you could direct that hotter air
back into the shop space.
--
Mr. P.V.'d
formerly Droll Troll
"Dave Lyon" wrote in message
news:a962g.908004$x96.138352@attbi_s72...

While we're on the subject...


My shop is a 4000 square foot metal building with just a little
insulation.
I've got 2 residential air conditioning units that keeps it bearable, but
not comfortable in our Missouri summers. I've heard that our humidity is
too
high to use an evaporitve cooler in this area effectively, but I've always
wondered how one of those would do in a shop that has two central air
units
running non stop. Would it actually add any cooling? Would it cause my
equipment to rust? It would sure be cheaper to operate than a 3rd AC unit.

In article a962g.908004$x96.138352@attbi_s72,
"Dave Lyon" wrote:

My shop is a 4000 square foot metal building with just a little insulation.
I've got 2 residential air conditioning units that keeps it bearable, but
....
It would sure be cheaper to operate than a 3rd AC unit.

Have you considered that more insulation would cost _nothing_ to run,
and enough of it could even get you down to running one A/C unit?

--
Cats, coffee, chocolate...vices to live by

Short answer: no, a swamp cooler won't work for you.

An evaporative cooler works by evaportaing water into the air OF THE
ROOM. The evaporation cools the air and raises the humidity. It works
fine in the desert where the dew point is in the single digits. It also
works ok in more moist areas where you want to cool down a really hot
area like a furnace room or warehouse. Where it doesn't work is where
you want to keep the temp fairly comfortable AND the humidity down.

In your case, your current AC units are spending a fair amount of time
and energy ($$) pulling water OUT of the air. Using an evaporative
cooler will just be at cross purposes. Not to mention dumping a lot of
moisture into the air to rust your tools.......

You should investigate ceiling fans, floor fans, sealing up the walls,
or even a sprinkler for the roof. You might also check on the
efficiency on your exisiting units. The small 5k btu units are really
bad, going to a heavy duty 12k btu might be a better option and get your
efficiency rating up in the 12 or 13 range. A central AC unit is
expensive but it would allow you to direct cool air to your work area,
let the other parts of the shop get hotter.


Dave Lyon wrote:
While we're on the subject...


My shop is a 4000 square foot metal building with just a little insulation.
I've got 2 residential air conditioning units that keeps it bearable, but
not comfortable in our Missouri summers. I've heard that our humidity is too
high to use an evaporitve cooler in this area effectively, but I've always
wondered how one of those would do in a shop that has two central air units
running non stop. Would it actually add any cooling? Would it cause my
equipment to rust? It would sure be cheaper to operate than a 3rd AC unit.

Have you considered that more insulation would cost _nothing_ to run,
and enough of it could even get you down to running one A/C unit?

--
Cats, coffee, chocolate...vices to live by

Ya, but I'm not sure what kind of insulation would hold up to a full time
machine shop. The insulation that is there, is a 4' wide roll with a green
sort of plastic facing the inside of the shop. The plastic is starting to
get holes and stuff in it from the years of abuse.

I've seen shops where they have sprayed insulation on the inside of the
walls. After a year or two, the walls are black with carbon dust and chips
that can't be effectively cleaned.

I'm just looking for a quick and easy solution, cause in the next few years
I'll probably be building a larger shop at a different location. Or, selling
the whole business and starting a different one.

Anybody looking for a small owner financed machine shop with a reasonable
customer base?

In your case, your current AC units are spending a fair amount of time
and energy ($$) pulling water OUT of the air.

Are you saying that the act of drawing the moisture out of the air uses more
energy? I was under the assumption that dehumidifying the air was just a
nice byproduct of running your AC unit.

If I understand what you are saying, a room at 90 deg will be cooled quicker
and easier by an AC unit if the humidity in that room is low than it would
if the humidity was high?

In article JQ62g.936717$xm3.550691@attbi_s21,
"Dave Lyon" wrote:

Ya, but I'm not sure what kind of insulation would hold up to a full time
machine shop. The insulation that is there, is a 4' wide roll with a green
sort of plastic facing the inside of the shop. The plastic is starting to
get holes and stuff in it from the years of abuse.

I've seen shops where they have sprayed insulation on the inside of the
walls. After a year or two, the walls are black with carbon dust and chips
that can't be effectively cleaned.

I guess I have seen exposed fire-retardant cellulose sprayed on things,
but would consider it a poor choice for a shop. Generally there needs to
be an inside wall covering (often more sheet steel in steel buildings,
or drywall) to keep the insulation from direct fire exposure, reduce
physical abuse, and make cleaning possible. Some types of ceiling
insulation (generally not foams) are OK to leave the inside face
exposed, but it's never a good idea on walls, as you have seen.

I'm just looking for a quick and easy solution

Cheap, fast, good pick (no more than) two? One product which can work,
but is not cheap, is a spray-on exterior polyurethane foam roof -
especially good if your present roof leaks, as it gets you insulation
and a new weather surface. I don't recall seeing that suggested for
walls, and doubt it would be. White steel panels spaced in 4-6 inches
from your present walls and fill behind with insulation of choice
(whatever's cheap) would be the best wall solution I can think of that's
durable and cleanable.

--
Cats, coffee, chocolate...vices to live by

On Fri, 21 Apr 2006 08:56:01 -0700, Larry Jaques wrote:
My shop is a 4000 square foot metal building with just a little insulation.

That's downright stupid, Dave. It costs -much more- to cool a poorly
insulated shop (year after year) than it does to insulate it properly,
a one-time cost. I'd almost guarantee that you pay more in electric
fees annually for that shop than you would for sheets of insulation.


I am tending to say that the most sensible solution with this metal
building would be to have this shed wide open and install some
powerful fans, 1/2 HP or so, and just blow air around to keep the body
cool.

i

That is correct--likely substantially more, depending depending. Water
vapor has substantially more mass than dry air, plus the heat of fusion,
ekc.

And the suggestion sprinklering the roof is good also--at least a tar flat
roof.
--
Mr. P.V.'d
formerly Droll Troll
"Dave Lyon" wrote in message
news:S172g.694836$084.661738@attbi_s22...

In your case, your current AC units are spending a fair amount of time
and energy ($$) pulling water OUT of the air.

Are you saying that the act of drawing the moisture out of the air uses
more
energy? I was under the assumption that dehumidifying the air was just a
nice byproduct of running your AC unit.

If I understand what you are saying, a room at 90 deg will be cooled
quicker
and easier by an AC unit if the humidity in that room is low than it would
if the humidity was high?

In article S172g.694836$084.661738@attbi_s22,
"Dave Lyon" wrote:

Are you saying that the act of drawing the moisture out of the air uses more
energy?

It does. Condensing water vapor (gas-liquid) causes it to give up the
latent heat of vaporization.

If I understand what you are saying, a room at 90 deg will be cooled quicker
and easier by an AC unit if the humidity in that room is low than it would
if the humidity was high?

Correct.

--
Cats, coffee, chocolate...vices to live by

That would be self-defeating. You'd be introducing hot air and
moisture into the air which would then have to be removed by the A/C


Hot air? How does an evaporative unit add hot air to a room?

You need R.H. of at most 15% to get an evaporative cooler to work well.
I can get a drop of about 20 degrees with a portable unit I've got at
that R.H., at 20% and above all I get is hot, wet air. Really good
only for the Southwest where the humidity is low for most of the hot
season. It evaporates water into the incoming air, so it increases the
R.H. inside, so, yes, there's a good chance it'll start equipment
rusting. Insulation, paint, partitioning and/or an exhaust fan(s)
located high up will work better.

Stan

Dave Lyon wrote:
In your case, your current AC units are spending a fair amount of time
and energy ($$) pulling water OUT of the air.


Are you saying that the act of drawing the moisture out of the air uses more
energy? I was under the assumption that dehumidifying the air was just a
nice byproduct of running your AC unit.





Of course it does, most of the energy by some accounts. The air cannot
get cool until the water is out. Thus opening the door is a BAD idea.

If I understand what you are saying, a room at 90 deg will be cooled quicker
and easier by an AC unit if the humidity in that room is low than it would
if the humidity was high?


Absotootly



AC notes;
My ~2400 sq ft shop that cost ~2k to heat in a new england winter last
year is kept generally below 80, and DRY by a single 24k btu wall ac
unit. I plan on adding some more, probably a mini split later

AC is a lifestyle; you turn it on in june and off in september. You shut
the windows and doors unless it is really cool and dry out. You NEVER
shut it off. I will turn mine on energy saver at night[fan is only on
with compressor]



The AC in your car is as big as the one in your house so it can pull the
tiny confines of the car down to 70 in a few minutes.

I find people who complain about the cost to heat the house, but sleep
with the window open and how their ac 'sucks' but they keep the door
open for some fresh air........

Dave Lyon wrote:
In your case, your current AC units are spending a fair amount of time
and energy ($$) pulling water OUT of the air.


Are you saying that the act of drawing the moisture out of the air uses more
energy? I was under the assumption that dehumidifying the air was just a
nice byproduct of running your AC unit.

Taking the water out of the air costs cost 540 BTU's per pound, same as
the heat needed to change water to vapor. So, it takes energy to squeeze
the water out. The reason the AC unit pulls the water out is that once
the coil temp gets down to the dewpoint temp, all the "cold" below that
temp goes into dropping the dewpoint. So if the coil temp could be as
low as 38 degrees and the dewpoint is say 60 degrees, your ouput air
will never get below 60 degrees until you pull some moisture out.



If I understand what you are saying, a room at 90 deg will be cooled quicker
and easier by an AC unit if the humidity in that room is low than it would
if the humidity was high?

Exactly right. A 1 ton (12kbtu/h) AC that puts out a gallon of water per
hour is spending 4320 (ie (8*540 )or 1/3 of the cooling capaity to pull
water out. Only 2/3rds left to cool.

Another factoid for your luncheon enjoyment: Your comfort level is much
more a factor of the dewpoint than the relative humidity. It really
comes down to how effective your sweat function is working. At 10F or
20f dewpoint (desert air), any sweat is immediatly evaporated. At 70F
dewpoint, the whole sweat thing doesn't work well (difference between
98F body temp and the dewpoint). Most people feel dewpoint in the 60's
to be "fairly humid" and starting to get uncomfortable. 50's is "nice",
40's is "dry"

What all that says is that pulling the dewpoint down WITHOUT changing
the temp will FEEL cooler. So keep the door closed!!!

Cheers.

Exactly right. A 1 ton (12kbtu/h) AC that puts out a gallon of water per
hour is spending 4320 (ie (8*540 )or 1/3 of the cooling capaity to pull
water out. Only 2/3rds left to cool.



Thank you. My mind works better with numbers. I have a much better
understanding of the energy needed to cool a room now.

On Fri, 21 Apr 2006 16:22:40 GMT, with neither quill nor qualm, "Dave
Lyon" quickly quoth:

That would be self-defeating. You'd be introducing hot air and
moisture into the air which would then have to be removed by the A/C

Hot air? How does an evaporative unit add hot air to a room?

By sucking it in from outside. A/C units recycle interior air while
dehumidifying and cooling it. Swamp coolers suck in outside air and
pass it over water (humidifying it) in an attempt to cool it. Running
both would be self-defeating because the swamp-cooled air would still
be hotter than that coming from the a/c units.

Consider doing a quick and dirty tubafore interior wall/ceiling
sub-structure around the inside of the shop with foamed-in-place or
foamboard filling. An OSB interior would stand up to the abuse pretty
well.


..-.
Better Living Through Denial
---
http://www.diversify.com Wondrous Website Design

On 21 Apr 2006 09:27:53 -0700, with neither quill nor qualm,
quickly quoth:

You need R.H. of at most 15% to get an evaporative cooler to work well.
I can get a drop of about 20 degrees with a portable unit I've got at
that R.H., at 20% and above all I get is hot, wet air. Really good
only for the Southwest where the humidity is low for most of the hot
season. It evaporates water into the incoming air, so it increases the
R.H. inside, so, yes, there's a good chance it'll start equipment
rusting. Insulation, paint, partitioning and/or an exhaust fan(s)
located high up will work better.

I worked installing a/c units on new pickups in Phoenix, AZ in '74.
The shop had 4 large swamp coolers. One hot and very dry day, it was
118F outside. The swampers held it down to a nice 108F inside. Ugh!


..-.
Better Living Through Denial
---
http://www.diversify.com Wondrous Website Design

On Fri, 21 Apr 2006 15:26:33 GMT, "Dave Lyon"
wrote:


Have you considered that more insulation would cost _nothing_ to run,
and enough of it could even get you down to running one A/C unit?

--
Cats, coffee, chocolate...vices to live by

Ya, but I'm not sure what kind of insulation would hold up to a full time
machine shop. The insulation that is there, is a 4' wide roll with a green
sort of plastic facing the inside of the shop. The plastic is starting to
get holes and stuff in it from the years of abuse.

I've seen shops where they have sprayed insulation on the inside of the
walls. After a year or two, the walls are black with carbon dust and chips
that can't be effectively cleaned.

I'm just looking for a quick and easy solution, cause in the next few years
I'll probably be building a larger shop at a different location. Or, selling
the whole business and starting a different one.

Anybody looking for a small owner financed machine shop with a reasonable
customer base?

Spray urethane and cover with sheet steel siding (or sheet aluminum,
or wallboard, or what-have-you)on the inside to make it easy to clean
and fire-proof.
*** Posted via a free Usenet account from http://www.teranews.com ***

"Larry Jaques" wrote in message
...
On Fri, 21 Apr 2006 16:22:40 GMT, with neither quill nor qualm, "Dave
Lyon" quickly quoth:

That would be self-defeating. You'd be introducing hot air and
moisture into the air which would then have to be removed by the A/C

Hot air? How does an evaporative unit add hot air to a room?

By sucking it in from outside. A/C units recycle interior air while
dehumidifying and cooling it. Swamp coolers suck in outside air and
pass it over water (humidifying it) in an attempt to cool it.

Oh, I see. All of the evaporative units that I've seen use the air from
inside the building just like a normal AC does.

On Fri, 21 Apr 2006 20:38:37 GMT, "Dave Lyon"
wrote:


"Larry Jaques" wrote in message
.. .
On Fri, 21 Apr 2006 16:22:40 GMT, with neither quill nor qualm, "Dave
Lyon" quickly quoth:

That would be self-defeating. You'd be introducing hot air and
moisture into the air which would then have to be removed by the A/C

Hot air? How does an evaporative unit add hot air to a room?

By sucking it in from outside. A/C units recycle interior air while
dehumidifying and cooling it. Swamp coolers suck in outside air and
pass it over water (humidifying it) in an attempt to cool it.

Oh, I see. All of the evaporative units that I've seen use the air from
inside the building just like a normal AC does.

The little portable coolers do use room air, but they're meant more
for spot cooling rather than room cooling. The built-in or window-
mount evaporative cooler units bring in outside air, dump a lot of
moisture into it, and will help some in a dry climate. And you need a
few windows or a door open, so that airflow has a way out, too.

I'll go with the rest - insulate and weather strip that shop,
pronto. Put at least R-13 Fiberglass batts in the walls, and someone
mentioned OSB instead of drywall, which will work fine if finished in
an enamel paint - do NOT leave raw wall surface exposed. You want to
make sure splashes of oil and muck don't soak in.

If you can find it cheap (good luck...) the fiberglass reinforced
plastic pebble-finish panels from commercial kitchens would be the hot
ticket over a layer of 1/2" drywall for fireproofing, it's impervious
to almost everything - hot wrench excluded. And you can caulk around
the plastic extrusion T-joiner strips to make it watertight.

Put as much insulation in the ceiling as you can - R-22 or better,
and then make sure you ventilate the attic above the shop with
turbines and eave venting for intake. Same as a house, if the attic
is 160F Plus, the heat will radiate down into the shop. If it's a
cathedral exposed ceiling, you need to space the insulation away from
the sheathing - leave an air gap above the insulation, and have eave
and ridge ventilation to keep the roof from melting.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.