I would like to put a "window" a/c unit in my shop. What BTU would I need to
cool a 24X40X12 high shop ? I would like something that would actually cool
it down and shut off, not run constantly to try and keep up.
Thanks,
Iowa883

BTW : lets say cool it down to 75 degrees , I also have R19 insulation in
the walls and blow in 6"thick on the ceiling . If this would help out your
calculations.

"Iowa883" wrote in message
...
I would like to put a "window" a/c unit in my shop. What BTU would I need
to
cool a 24X40X12 high shop ? I would like something that would actually
cool
it down and shut off, not run constantly to try and keep up.
Thanks,
Iowa883

BTW : lets say cool it down to 75 degrees , I also have R19 insulation in
the walls and blow in 6"thick on the ceiling . If this would help out your
calculations.



Sorry dude a "window ac" is not what your looking for. My home has a 2.5 ton
unit package unit and is about the same size as your shop.

On Sun, 03 Jul 2005 09:42:30 -0500, Iowa883 wrote:

I would like to put a "window" a/c unit in my shop. What BTU would I need to
cool a 24X40X12 high shop ? I would like something that would actually cool
it down and shut off, not run constantly to try and keep up.

A "window" type unit will not be able to cool that space. Not even close.

--
If you're not on the edge, you're taking up too much space.
Linux Registered User #327951

Iowa883 wrote:
I would like to put a "window" a/c unit in my shop. What BTU would I need to
cool a 24X40X12 high shop ? I would like something that would actually cool
it down and shut off, not run constantly to try and keep up.
Thanks,
Iowa883

BTW : lets say cool it down to 75 degrees , I also have R19 insulation in
the walls and blow in 6"thick on the ceiling . If this would help out your
calculations.

I'm not doing the calculations for you, but I can point you to an
online tool.

Read up before you make any decisions. The AC shouldn't be oversized
for various reasons - it shouldn't shut off too soon.

http://tinyurl.com/acg33

R

"Iowa883" wrote in message
...
I would like to put a "window" a/c unit in my shop. What BTU would I need
to cool a 24X40X12 high shop ? I would like something that would actually
cool it down and shut off, not run constantly to try and keep up.
Thanks,
Iowa883

BTW : lets say cool it down to 75 degrees , I also have R19 insulation in
the walls and blow in 6"thick on the ceiling . If this would help out your
calculations.



To help you out a bit as the others have chickened out!
I have a 24x38x9 foot shop, insulated similar to yours. I bought a used
11,000 BTU window shaker, it was cheap, so I was not out much. It would not
keep up unless I let it run constantly. Opening the overhead door to run a
vehicle in would cause it to lose ground and not catch up. It did a
wonderful job of humidity removal, so even if the temps rose close to 80F it
was still more comfortable in the shop than without the AC.

I have since replaced the furnace and added central air to the shop. I went
with a 1-1/2 ton condensing unit and it does well. I can leave the doors
open, then close the shop up, and it will catch up and cool the shop down to
the set temp in a reasonable time.

Now factors as windows, doors, and quality of the doors will have a big
effect on BTU needed, so your results my differ from mine. Considering your
shop has about 50% more cubic feet than mine I would guess you will need at
least 2 ton to cool it. Two ton window units are unheard of so one unit will
not do it. Perhaps two of the larger window units, (10,000 - 11,000 BTU),
will make a dent in the BTU load. Anything less and I would not bother.
You better get out you credit card! Window units of this size are $500 -
$600, unless you can dig up a couple used units!
E-mail is good.
Greg

"Dan C" wrote in message
news
On Sun, 03 Jul 2005 09:42:30 -0500, Iowa883 wrote:

I would like to put a "window" a/c unit in my shop. What BTU would I need
to
cool a 24X40X12 high shop ? I would like something that would actually
cool
it down and shut off, not run constantly to try and keep up.

A "window" type unit will not be able to cool that space. Not even close.

Actually, it can. Not some tiny wimpy unit, but probably two good sized
ones. You have two considerations. The overall Btu needed to remove the
heat, and also, you must also have proper air circulation. A single unit
is not going to move the air needed to make the entire shop comfortable.

I'd consider mounting something like two 15,000 or 18,000 Btu units through
the wall. It would probably be cheaper than a single central unit and a
duct and blower system. Stop one is to determine the real needs and then
figure how the best way to get it.
--
Ed
http://pages.cthome.net/edhome/

"Iowa883" wrote in message
...
I would like to put a "window" a/c unit in my shop. What BTU would I need
to
cool a 24X40X12 high shop ? I would like something that would actually
cool
it down and shut off, not run constantly to try and keep up.
Thanks,
Iowa883

BTW : lets say cool it down to 75 degrees , I also have R19 insulation in
the walls and blow in 6"thick on the ceiling . If this would help out your
calculations.


Roughly same size shop as ours...

We use a 3-1/2 ton "package heat pump unit"......self-contained....this sits
on a pad outside with both ducts running through the wall and into the
shop....you might also see this style of unit referred to as "ptac" or
"rtu".....

Probly at first glance the 3-1/2 tons would seem oversized for this
climate...but...we have heat gains that wildly vary depending on what work
is actually being processed on any given day--this being due to some fairly
large electric motors, hydraulic units, etc.....

Probly better yet would be if we were to also add a small window unit, and
run it more or less constantly in order to help keep humidity under control.

--

SVL

For something like that, consider a mini-split heat pump, especially if
you want heat and you don't have access to natural gas (just
electricity).

There are lots of manufacturers (mostly Japanese where they were
invented), but I just installed a Sanyo for a space in my home that's
about 800 sq. feet. I put in a 12,500 BTU unit March 05, have operated
it for four months and it works great. You might need the 18,000 BTU
unit for the insulation level you have. Check out Sanyo's
http://tinyurl.com/b32m6. It's a more significant purchase (approx.
$2500 installed if you buy the unit online and then find a local HVAC
installer), but it's more versatile (giving you heat and cool) and
produces heat at 1/3 the cost of standard electricity-based heaters.

Don't blindly oversize your unit...cycling mechanical equipment too
much reduces its life span....

Andre' A.

On Sun, 03 Jul 2005 16:40:33 +0000, Edwin Pawlowski wrote:

I would like to put a "window" a/c unit in my shop. What BTU would I
need to cool a 24X40X12 high shop ? I would like something that would
actually cool it down and shut off, not run constantly to try and keep
up.

A "window" type unit will not be able to cool that space. Not even
close.

Actually, it can. Not some tiny wimpy unit, but probably two good sized
ones.

The original poster said "a window a/c". He didn't mention multiple units.

A single unit is not going to move the air needed to make the entire shop
comfortable.

I believe that's what I said, isn't it?

--
If you're not on the edge, you're taking up too much space.
Linux Registered User #327951

Two ton window units are unheard of so one unit will
not do it. Perhaps two of the larger window units, (10,000 - 11,000 BTU),
will make a dent in the BTU load. Anything less and I would not bother.
You better get out you credit card! Window units of this size are $500 -
$600, unless you can dig up a couple used units!
E-mail is good.
Greg



Two Ton Window units are not all that unheard of... That's 24000
BTU's of cooling. Back in the 70's we had Sears put in a 28000 BTU
window unit for our house to cool the lower level of about 1200 sq.
feet. Even on the lowest setting on the hottest day of the year it
was almost instant relief from the heat as it would spit out ice cold
air out the front. I don't think we ever used the high setting.

The unit was a monster, but fit in a regular window and needed cross
braced support arms that rested on the bricks below to hold up the
projecting end. Also, it was too heavy to move so it was designed to
stay in place during the winter months. Sears sold a cover for the
outside to keep the ice and snow out of it. Needless to say, it
required a special 240 V. circuit and it was not cheap to run.

Beachcomber

"Dan C" wrote in message
The original poster said "a window a/c". He didn't mention multiple
units.

A single unit is not going to move the air needed to make the entire shop
comfortable.

I believe that's what I said, isn't it?


No, you said:
A "window" type unit will not be able to cool that space. Not even
close.

You offered no reason, no alternatives, no nothing but a simple declaration
that it would not work. It can, in fact work and I've seen it done a few
times. Best solution? I don't know. It is probably the cheapest compared
to a setup with evaporator, blower, remote condenser, mounting pad, etc.

A single unit may even work with some secondary fans for air circulation.
I've not seen the actual space so can't give specifics.

I'm sure the OP learned something from your post. Thank you for
participating.
--
Ed
http://pages.cthome.net/edhome/

"Iowa883" wrote in message ...
I would like to put a "window" a/c unit in my shop. What BTU would I need to
cool a 24X40X12 high shop ? I would like something that would actually cool
it down and shut off, not run constantly to try and keep up.
Thanks,
Iowa883

BTW : lets say cool it down to 75 degrees , I also have R19 insulation in
the walls and blow in 6"thick on the ceiling . If this would help out your
calculations.

That 40' length is the major problem. You won't get any
kind of decent cooling with a single wall unit.

Is it possible to partition the shop into two 24x20' areas?

Iowa,

You have about 1000 square feet. My hoouse is 2000 square feet in
myrtle Beach, SC and a 2-ton heat pump heats and cools it just fine.
On that basis a 1 ton window unit would do the job for you.

However, if your weather is different than mine, and it probably is,
slightly larger or smaller may be required.

To do a proper load calculation, you also need to know the area of the
windows, which type they are, which way they face, how big the overhang
is and how far above the windows the overhang is. You need the same
thing for doors, except direction is not very important. R-19 in the
walls and ceilings is better than most home shops, so that helps.

Is this a home shop, or a commercial shop?
How many people are in there?
How many, what wattage, and what type of lights?

What type of machinery, how much power does it use, how many pieces of
equipment, what duty cycle and what hours of operation?

What indoor temperature do you need?

Are you running any exhaust fans or makeup air fans? How many and what
CFM?

How tight is the construction?

Lots of variables involved here. If you size it off Square Feet of
floor space, even if you allow for ceiling height, you may be way off
on your sizing.

Stretch

"Beachcomber" wrote in message
...



Two Ton Window units are not all that unheard of... That's 24000
BTU's of cooling. Back in the 70's we had Sears put in a 28000 BTU
window unit for our house to cool the lower level of about 1200 sq.
feet. \


Thirty years ago you had 24,000 BTU AC, does help much today! They probably
exist, but it would be rare!
Greg

here's a window beast

http://www.amazon.com/exec/obidos/tg...506438-6978355

On Sun, 3 Jul 2005 22:12:22 -0500, "Greg O"
wrote:

Thirty years ago you had 24,000 BTU AC, does help much today! They probably
exist, but it would be rare!
Greg


Not rare at all. Most any place selling window units will have one or
two different models in this size or larger.

Steve B.

"Stretch" wrote in message
ups.com...
Iowa,

You have about 1000 square feet. My hoouse is 2000 square feet in
myrtle Beach, SC and a 2-ton heat pump heats and cools it just fine.
On that basis a 1 ton window unit would do the job for you.

However, if your weather is different than mine, and it probably is,
slightly larger or smaller may be required.

To do a proper load calculation, you also need to know the area of the
windows, which type they are, which way they face, how big the overhang
is and how far above the windows the overhang is. You need the same
thing for doors, except direction is not very important. R-19 in the
walls and ceilings is better than most home shops, so that helps.

Is this a home shop, or a commercial shop?
How many people are in there?
How many, what wattage, and what type of lights?

What type of machinery, how much power does it use, how many pieces of
equipment, what duty cycle and what hours of operation?

What indoor temperature do you need?

Are you running any exhaust fans or makeup air fans? How many and what
CFM?

How tight is the construction?

Lots of variables involved here. If you size it off Square Feet of
floor space, even if you allow for ceiling height, you may be way off
on your sizing.



Stretch,

Not a big deal, but could you perhaps leave some more attributes in your
posts ???

It appears from here as though you had answered the op's question through my
post--where in actuality my own hvac situation is fairly well under
control....

On the other hand, I'm somewhat flattered if in fact you skipped over the
previous posts and then chose mine to be the first one you decided to read.

--

SVL

Iowa883 wrote:

I would like to put a "window" a/c unit in my shop. What BTU
would I need to cool a 24X40X12 high shop ? I would like
something that would actually cool it down and shut off,
not run constantly to try and keep up.

lets say cool it down to 75 degrees , I also have R19
insulation in the walls and blow in 6"thick on the ceiling .

Consumer Reports has a worksheet for homes at:

http://www.consumerreports.org/main/...lder_id=444721

but a shop can give a very different heat load.

The largest 110VAC window air conditioner I know of is rated at about
15,000 BTU/hr, but 36,000 BTU/hr is available with 220VAC. I seriously
doubt you need the latter or nay 220VAC unit, and smaller sizes are so
cheap that 2 of them may cost less than a single larger unit with the
same cooling power.

On Mon, 04 Jul 2005 00:29:21 -0700, PrecisionMachinisT wrote:

On the other hand, I'm somewhat flattered if in fact you skipped over the
previous posts and then chose mine to be the first one you decided to read.

I think the real reason was his complete and utter cluelessness. Not
uncommon in those posting to Usenet from Google Groups.

--
If you're not on the edge, you're taking up too much space.
Linux Registered User #327951

"Dan C" wrote in message
news
On Mon, 04 Jul 2005 00:29:21 -0700, PrecisionMachinisT wrote:

On the other hand, I'm somewhat flattered if in fact you skipped over
the
previous posts and then chose mine to be the first one you decided to
read.

I think the real reason was his complete and utter cluelessness. Not
uncommon in those posting to Usenet from Google Groups.


I think there's probly hope for him, judging from the quality of information
he has given in the past.

Otherwise, I wouldn't have even bothered.

--

SVL

On 4 Jul 2005 06:48:32 -0700, wrote:



Iowa883 wrote:

I would like to put a "window" a/c unit in my shop. What BTU
would I need to cool a 24X40X12 high shop ? I would like
something that would actually cool it down and shut off,
not run constantly to try and keep up.

lets say cool it down to 75 degrees , I also have R19
insulation in the walls and blow in 6"thick on the ceiling .

Consumer Reports has a worksheet for homes at:

http://www.consumerreports.org/main/...lder_id=444721

but a shop can give a very different heat load.

The largest 110VAC window air conditioner I know of is rated at about
15,000 BTU/hr, but 36,000 BTU/hr is available with 220VAC. I seriously
doubt you need the latter or nay 220VAC unit, and smaller sizes are so
cheap that 2 of them may cost less than a single larger unit with the
same cooling power.


The capital costs of two 110VAC units may be less for a given number
of BTUs but the real concern is going to be operating costs. One big
24000 BTU unit is almost always going to be more efficient than two
12000 BTU units when you consider the cost of converting electrical
watts to cooling capacity. (You will have one more compressor...one
more blower, etc.)

Beachcomber

"Iowa883" wrote in message
...
I would like to put a "window" a/c unit in my shop. What BTU would I need to
cool a 24X40X12 high shop ? I would like something that would actually cool it
down and shut off, not run constantly to try and keep up.
Thanks,
Iowa883

BTW : lets say cool it down to 75 degrees , I also have R19 insulation in the
walls and blow in 6"thick on the ceiling . If this would help out your
calculations.


This is Turtle.

If you want a Guess here . well Here is where you can go to get a good guess.

http://www.thisoldhouse.com/toh/knowhow/calculator/ac

Plug and Play !

TURTLE

Beachcomber wrote:
On 4 Jul 2005 06:48:32 -0700, wrote:

The largest 110VAC window air conditioner I know of is rated
at about 15,000 BTU/hr, but 36,000 BTU/hr is available with
220VAC. I seriously doubt you need the latter or any 220VAC
unit, and smaller sizes are so cheap that 2 of them may cost
less than a single larger unit with the same cooling power.

The capital costs of two 110VAC units may be less for a given
number of BTUs but the real concern is going to be operating
costs. One big 24000 BTU unit is almost always going to be
more efficient than two 12000 BTU units when you consider the
cost of converting electrical watts to cooling capacity. (You
will have one more compressor...one more blower, etc.)

Nonsense. While a larger unit is inherently more efficient, just as
220VAC is inherently more efficient than 110VAC for motors, in reality
there's no difference, and small units are commonly available with
efficiencies of EER 10 (roughly like SEER 12). Also on a milder day,
operating just 1 of the smaller units may be more efficient since it'll
probably remove more humidity by running continuously.

Greg O wrote:
"Iowa883" wrote in message
...

I would like to put a "window" a/c unit in my shop. What BTU would I need
to cool a 24X40X12 high shop ? I would like something that would actually
cool it down and shut off, not run constantly to try and keep up.
Thanks,
Iowa883

BTW : lets say cool it down to 75 degrees , I also have R19 insulation in
the walls and blow in 6"thick on the ceiling . If this would help out your
calculations.




To help you out a bit as the others have chickened out!
I have a 24x38x9 foot shop, insulated similar to yours. I bought a used
11,000 BTU window shaker, it was cheap, so I was not out much. It would not
keep up unless I let it run constantly. Opening the overhead door to run a
vehicle in would cause it to lose ground and not catch up. It did a
wonderful job of humidity removal, so even if the temps rose close to 80F it
was still more comfortable in the shop than without the AC.

I have since replaced the furnace and added central air to the shop. I went
with a 1-1/2 ton condensing unit and it does well. I can leave the doors
open, then close the shop up, and it will catch up and cool the shop down to
the set temp in a reasonable time.

Now factors as windows, doors, and quality of the doors will have a big
effect on BTU needed, so your results my differ from mine. Considering your
shop has about 50% more cubic feet than mine I would guess you will need at
least 2 ton to cool it. Two ton window units are unheard of so one unit will
not do it. Perhaps two of the larger window units, (10,000 - 11,000 BTU),
will make a dent in the BTU load. Anything less and I would not bother.
You better get out you credit card! Window units of this size are $500 -
$600, unless you can dig up a couple used units!
E-mail is good.
Greg



I picked up a 11,800 btu like-new for $20.

http://washingtondc.craigslist.org/fur/85580838.html