Suggestions on how to keep my shop cool...

Forum 2005-2010 (read only) General Bar Sport
1

All,

Just looking for some more brains on this.

I live in Phoenix, Arizona; last night at about 11pm the outside temperature was hovering around 100 degrees F.

I have a shop attached to my house (but only accessible via outside doors) that I do most of my electronics in. Before the summer set in, I purchased used off of craigslist a portable A/C unit (not a cooler; its an actual air conditioner with a compressor, and a hose that carries away the hot exhaust).

I had planned on hooking the hose up to a hole cut in my attic access in my shop to exhaust the hot air into my attic (and out the attic vents, ultimately). This didn't work, though - the unit overheats and shuts down within a half-hour.

My only solution so far, then, it to run the hose out the door, and shut the door on it, propping it closed with a toolbox; this unfortunately leaves a gap about 7 inches wide, so I am unable to cool the room below about 90 degrees F or so, which is nowhere near enough.

I am trying to avoid cutting holes in the wall or the doors, for a couple of reasons: 1) I'm not the greatest carpenter, and it wouldn't look good, 2) My wife doesn't want to see a hole in the wall, 3) At some point, maybe this winter, I am going to have ductwork run to my shop from the house A/C and I don't want a hole in the wall to repair.

I also don't have access to the windows in my shop anymore (I put large gorrilla racks in front of them for storage purposes, and there's no way I am moving them until winter).

So - my question is: Where would you run the hot exhaust air?

The only solution I have been able to come up with is to try, once again, to run the hose up to the attic, but at the end of the hose, mount a high-speed 120 VAC muffin fan that can move as much air as possible; I have a feeling the overheating is being caused by the fan not being powerful enough to push the airflow up through the tube and into the attic at a rate so it doesn't overheat.

I am just curious if anyone else has a solution that would keep me as cool as if I were in the main house (where the temperature is set to about 75 degrees F - but for my shop, I would be happy with 80-85 F), that doesn't require the assistance of a contractor to set up...?

:slight_smile:

2

My only solution so far, then, it to run the hose out the door, and shut the door on it, propping it closed with a toolbox; this unfortunately leaves a gap about 7 inches wide, so I am unable to cool the room below about 90 degrees F or so, which is nowhere near enough.

Seems like the only viable solution to me with the current situation. I'd give that a try and see how it works.

3

Wow, that's a very non-standard application for an air conditioner. I assume that by portable, you mean a "window shaker".

Have you considered an evaporative cooler? That should work quite well in your environment. I don't know how much water would be required, though. I feel for you as I speak often with an A/C distributor or ours that is based in Phoenix. He's a pretty imaginative and very experienced guy. I could contact him and ask if he's willing to discuss some alternatives with you. If so, I could PM the info to you.

I don't really have any ideas to help. Only thing I can think of is to run water over the condenser coil to keep it cool. This really doesn't deal with your door problem, though. I'll keep you posted.

4

Seems like the only viable solution to me with the current situation. I'd give that a try and see how it works.

Well - that's what I am doing now, and it stinks as a solution; even with the air blowing straight on me, I am still sweatin'! ;D

I've thought about trying to block the gap in the door with either some thin plywood cut to the width, so there would be a "hole" at the bottom of the door gap for the hose, but it doesn't seem like a very elegant solution, and I am having trouble coming up with a method to attach it so that it isn't permanent, and would still allow the door to be used (especially if I need to get out fast because of smoke or fire).

Wow, that's a very non-standard application for an air conditioner. I assume that by portable, you mean a "window shaker".

No - this is an A/C unit on wheels, with a hose that is meant to run out of the area being cooled; kinda like this:

http://www.cleaning-guide.com/images/portable-air-conditioner-window.jpg

Have you considered an evaporative cooler? That should work quite well in your environment.

Yes - I tried that last year; I have small portable shop cooler that I can hook the hose up to; It works ok, but I face the same problem in that I now need a way to get incoming fresh air; I would prop it in the door the same way, but it was hard to get around, difficult to hook up, and you were muggy. Plus, it didn't work well during the monsoon with its higher moisture (which is getting here quick).

I don't know how much water would be required, though. I feel for you as I speak often with an A/C distributor or ours that is based in Phoenix. He's a pretty imaginative and very experienced guy. I could contact him and ask if he's willing to discuss some alternatives with you. If so, I could PM the info to you.

That evap cooler actually doesn't take much; we once cooled areas in our house when the A/C died on us (bad relay I had to replace). We ended up filling it using a pitcher.

I don't think I need the help of a professional - like I said, I plan to have ductwork run from my main A/C unit at some point in the future.

I don't really have any ideas to help. Only thing I can think of is to run water over the condenser coil to keep it cool. This really doesn't deal with your door problem, though. I'll keep you posted.

Good idea, but not possible (really) with this kind of indoor unit; I would then also have to deal with getting rid of the water, plus running the hose into my shop (no water access in here). Thanks for the ideas, though - its what I am ultimately looking for, and hoping maybe somebody comes up with something I haven't thought of.

BTW - you wouldn't believe how hot that hose and the air it moves out can get; it has no problem moving the heat, I just need a way to move it out of the area I am in, and not let more in (insulation isn't really a problem, as long as I can keep the door closed - which with the way I have it set up, I can't, so I can only cool it down so far).

:slight_smile:

5

what about making a skirt out of canvas or heavy plastic, could even go nuts and sew a pipe in the bottom so it stays down (or just use some machine screws nuts and washers for weight)

you could roll it up when not in use and secure it with some velcro, and it could all be attached with adhesive tape so no damage later on

6

I think you can buy little electric fridge plates, from sparkfun (ironic eh?), put some of these in your seat for additional cooling. I'll hunt down a link...

7

what about making a skirt out of canvas or heavy plastic, could even go nuts and sew a pipe in the bottom so it stays down (or just use some machine screws nuts and washers for weight)

you could roll it up when not in use and secure it with some velcro, and it could all be attached with adhesive tape so no damage later on

I actually like this idea. If I set things up, maybe using a blackout roller shade, and made it wider than the door opening, with a hole to allow me to lead the hose out. Hmm - something to definitely mull over!

Thanks Osgeld!

:slight_smile:

8

Just move to a cooler location. I can recommend the California coastal areas. The summer fog in the San Francisco bay is like having free AC. Even on hot days the air cools down quickly once the sun sets, even when there is no fog. Of course that is all possible because of the very cold ocean current running south from Canada. :wink:

Lefty

9

Get a heavy curtain to hang up.

or as osgeld points out you can put on a skirt. Air things out so to speak.

what about making a skirt out of canvas or heavy plastic, could even go nuts and sew a pipe in the bottom so it stays down (or just use some machine screws nuts and washers for weight)

you could roll it up when not in use and secure it with some velcro, and it could all be attached with adhesive tape so no damage later on
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10

I can recommend the California coastal areas. The summer fog in the San Francisco bay is like having free AC. Even on hot days the air cools down quickly once the sun sets.

My wife and I like Cali as a state, but we hate the government. We've often talked about "moving" to Washington or Oregon before. Honestly, though, we both love Arizona (we're not too happy about the government here, either - but at least we can still open carry).

The heat is really only a "problem" in the July/August time of year, it tapers off on months before and after that; heck, up until the end of May, we would turn our A/C off (even then, it was only set to 78-79 F), open up the windows, and put some fans in to blow in outside air (night temps during those times are mid 60s to mid 70s generally).

I am pretty sure my A/C unit would work great if I could just figure out a good way to get the exhausted hot side air out of my shop without leaving such a large gap open in my door. Osgeld's suggestion of a "skirt" of some sort is making me think of possible options. Part of the problem with idea is the arrangement of the doors and what I have near them (double doors, shelf directly above, and they swing inward).

I am sure with enough thought, a solution can be had (probably figure one out that works just as it starts to cool off here)...

;D

11

or as osgeld points out you can put on a skirt. Air things out so to speak.

I think you misinterpreted what he was suggesting, copiertalk!

;D

But I have been known to wear a sarong around the house (and at Burning Man). Maybe I need to wear the sarong, then run the cold vent output up into it? Chill the boys down, so to speak...

;D

My wife might not like it, though!

12

Go to someplace like Habitat's recycled building material store and buy a second-hand door. Once you have your more-permanent arrangements, you can re-sell it to someone with a cat ("Comes with a starter hole for installing your pet door at no extra charge!"), or put it on sawhorses and use it as a temporary outdoor work table.

13

Go to someplace like Habitat's recycled building material store and buy a second-hand door.

Can't; they're not standard sized. We had this same problem when we needed to replace our back doors (two full mullioned french doors) after our dog ate through them (long story, but true); we couldn't find doors that would fit; they were apparently custom made (the doors exit from an addition to the original house that was put on before we moved in). It was going to cost over a grand to have them replaced, so we decided to wait until we could afford new windows and insulation put in.

We finally had that done last year, but having that door custom replaced was still going to be an expensive proposition, plus we wanted a way to be able to open the windows when it was cool out (before, we opened the whole door, which let in insects). That meant we had to buy new standard doors, and it was cheaper to do that than having the french doors custom made to fit - even though they had to redo the opening to make the new frame fit. To have this same process done to my shop would be more money than I want to spend right now.

Thanks for the suggestion, though!

:slight_smile:

14

I second the notion of Habitat, or a secondhand building supply shop, for a door. Worst case, get one that's too big and cut it down to size. You will be surprised at how cheap a door can be.

My other thought - put a "cat flap" in the shop door. This won't be as ugly or home-made looking as a hole you cut, and it's not an outrageous thing to have on a door, either. The kit to install it will cost $20 and will come with trim to hide and seal the ugly cut edge. Then when you need the AC, just stuff the hose out the cat door. When you don't need the AC, it's not a big deal.

15

You got any windows? people use those type of A/C units in the UK as it's not worth installing a permanent unit for the 3 days per year that it's worthwhile. I've seen a cludge on the market that is basically a board that goes over an open window then you shut the window against it so that it seals and stays in place. It has a hole the same diameter as the A/C hose. Perhaps you could make one from Ply+ some pvc pipe and glue? If you have no windows - you could get a big sheet of foam board insulation cut it to door size +hole for A/C. Leave the normal shop door open and push your makeshift one in place? you could even add hinges and have it as a kind of screen door?

16

Could you not extend the hose directly to the attic vents? Would size a lot of trouble :slight_smile:

I could never live there, I cant stand temps over 80 ;D

17

ill_switch:

I second the notion of Habitat, or a secondhand building supply shop, for a door. Worst case, get one that's too big and cut it down to size. You will be surprised at how cheap a door can be.

As I said - these are fairly custom doors - so a lot of rework (which isn't going to happen in this heat!) would have to be done to get one to work. More trouble than its worth, ultimately.

My other thought - put a "cat flap" in the shop door. This won't be as ugly or home-made looking as a hole you cut, and it's not an outrageous thing to have on a door, either. The kit to install it will cost $20 and will come with trim to hide and seal the ugly cut edge. Then when you need the AC, just stuff the hose out the cat door. When you don't need the AC, it's not a big deal.

Hmm - that's a pretty good idea; I'll take it under consideration.

daveg360:

You got any windows? people use those type of A/C units in the UK as it's not worth installing a permanent unit for the 3 days per year that it's worthwhile. I've seen a cludge on the market that is basically a board that goes over an open window then you shut the window against it so that it seals and stays in place. It has a hole the same diameter as the A/C hose. Perhaps you could make one from Ply+ some pvc pipe and glue?

That's the problem - when I reorganized my shop over the winter, in order to maximize my storage space I put up a series of "gorilla racks" in front of my windows (I never looked out them or opened them, so it didn't matter to me - at the time). No way to change that now...

If you have no windows - you could get a big sheet of foam board insulation cut it to door size +hole for A/C. Leave the normal shop door open and push your makeshift one in place? you could even add hinges and have it as a kind of screen door?

That's a fairly good idea, but I don't know if my wife would go for the look; I could probably do that as a temporary thing like you said, though.

thegeekway:

Could you not extend the hose directly to the attic vents? Would size a lot of trouble

Not with the unit I have; I tried that at first (just going into the attic via a hole in my attic access panel; the soffet vent is only a few feet away from the access in my shop) - the AC unit overheated. I tried adding an extra fan to help pull the hot air out; it overheated, then the AC overheated.

Later (as in yesterday) I downloaded the manual to the unit and found that you have to keep the exhaust pipe as horizontal as possible, which really limits its application.

Here's the strange thing, though - on Friday night, I tried an experiment; I put the hose out the door like I normally do, and extended it away from my shop entrance. Then I propped up a board over the hose to close off the gap, and added another board on top of the door to close that gap. It wasn't perfect, but I just wanted to experiment to see if I could drop the temperature further by closing up the gap. I turned the unit on; it ran fine for about an hour and a half, then shut down - overheated. I found this odd because I could normally run the unit for hours if I didn't cover those gaps (how I normally run it). I am not sure what I am doing wrong, or if I just have a bum Craigslist "special" (very possibly). I am trying to get in contact with the manufacturer of the unit to find out about having it checked for repair.

In the meantime, I have my portable swamp cooler - but right now, that thing is near useless because we are heading into our "monsoon" season (high humidity and sweltering temperatures - swamp coolers don't help much).

Grumble.

I do have a plan, though - and its going to cost some, and I probably won't be able to put it into action until this winter at the earliest (or next spring). They make A/C units called "ductless mini-splits", in which the condensor is on the outside of the house (on the roof or next to a wall), with the power and refrigerant lines run inside the building to the heat exchanger, which can be hung on the wall or from the ceiling. The only problem is, while these units will run on regular house current, they typically draw a lot of amperage; more than what I have available on the circuit to my shop. So I am thinking I need an upgrade there to support it. But I wanted an upgrade anyhow. Where I might run into trouble, though, is the sizing of my upgrade, because if I have such a thing done, I would want a dedicated circuit for the A/C (20-25 amp), plus one for the shop (15 amp), plus a third for my server closet (15 amp) in my shop, plus a 40 amp 220V outlet for a future AC/DC welder - all in all, around a 100 amp upgrade for my shop - but I think my house is at its limit for its main panel! If that's the case, then it would depend on what the service level is to my house; it might be impossible without spending more money than I am willing to do (heck, it might be impossible without the power company doing upgrades - which I doubt they would do - the area I live in is older, dating from the early 1970s).

I guess we'll see what happens; for now, my activities in my shop are limited to short stints mainly late at night (when its cooler - like around 100 degrees or so!)...

;D

18

you might have to take some items off of your wishlist.

they make mini-splits that take 120VAC and draw less than 15 Amps, it will only provide about a ton of cooling or so but it is probably more than your portable puts out

19

you might have to take some items off of your wishlist.

Well - the problem is when they (previous owners) put the addition on my house, of which the shop is a part of, they used a single 15 amp circuit for the shop, a few plugs in the house, and various ceiling fans in the bedrooms (weird, I know - but it apparently passed inspection). In my shop I have my "server closet", which I current run two small servers off a large UPS plugged into one of the outlets in the shop (which is inside the closet).

I haven't had any issues with the power, but I think with the addition of an A/C unit, plus later I plan on hooking up another small PC for my workbench, plus my soldering iron, oscilloscope, and maybe later my mini-mill - I think I am getting close to the "trip point" of the breaker (I haven't actually measured, so I don't know for certain).

Which is why I wanted more circuits to spread the load; I realize this may not be possible if I am at my limit on the breaker box and/or the service level from the power company. When I do have this done, I plan on having a real contractor do it - this isn't going to be a DIY job; I want it done right so the house doesn't burn down!

:slight_smile:

they make mini-splits that take 120VAC and draw less than 15 Amps, it will only provide about a ton of cooling or so but it is probably more than your portable puts out

My shop is small - maybe 8' by 15' max; in theory, from what I have read, my current A/C unit should be able to cool it, but because of the hose and the fact that I don't have an easy way to lead it outside without a big gap in the door, etc - it just isn't working for me. I am planning on trying some other possibilities with it - maybe I can get it to work.

Since the split a/c unit is something for the future, I am trying to come up with a solution for "now" (short of just waiting out the summer); if I can't get the portable working the way it should, and I have no luck with the swampie (because of monsoon season), I am thinking about a way I can mount up a window a/c unit thru some kind of temporary "baffle" in the place of the door, made out of either 1/2-3/4 inch plywood, or maybe some kind of styrofoam board (and mount the a/c unit on a stand in front of the cutout hole). I am not sure how well this would work, but it might be worth the effort.

This summer has seemed to be hotter than last summer (maybe due to the monsoon?), certainly; not sure if that is truth or just faulty perception. If I want to do something in my shop, though, I need to figure something out, or just forget it until the cool season comes back.

:slight_smile:

20

cut a hole in the wall (nicley) and explain after the air conditioner it can be a vent to get paint fumes and beer farts out of the small area :smiley: