I’ve got a 12×16 shop in low humidity Central California where the summer temps routinely are 95-105. I was thinking an evaporative cooler would be ideal for my size shop and the low cost but then wondered about the wisdom of using one around the project wood I have in the shop (ie, would the higher humidity air blowing from the cooler be enough to cause problems with wood movement?). I can’t seem to find much info at all on cooling a shop. Can anyone give me some advice? It’s not worth it for me to put in an air conditioner….my other option would be just regular fans. Anyone have experience using evaporative (swamp) coolers in a woodshop?
Thank you,
charlie
Replies
Excellent question, I am considering the same thing although I would be blowing air from the evap cooler into a corner (where I am setting up a shop) of a larger 40'x60' building. I look forward to the replies. There is an alternative to the traditional swamp cooler that uses sort of a heat exchange chamber so that the air is not pulled directly through the wet pads -- they provide low-cost cooling with less humidity increase (no compressor just a blower motor). The brand name that I have experience with (I use one on my house) is MasterCool.
When I lived in Phoenix we installed a swamp cooler in the garage. It reduced the temperature from about 100 degrees to 80-85 degrees and raised the relative humidity from 25% to about 45-50%.
Just for a frame of reference, that change in relative humidity will cause a 12" wide red oak board to expand about 1/8th of an inch. Of course, it will shrink the same amount if you move it to an environment that is 25%,
They work OK in Phoenix because the humidty is so phenomenally dry there. The Central CA Valley ain't as dry as that 'don't think I'd want to use in the a shop in most locatation. AC and lots of insulation are best. I don't think it would take many BTU's to cool a well-insulated 12x16 shop.
Edited 5/12/2007 8:53 pm by BarryO
Howie - thanks very much for the info. I looked up historical temp and humidity data for Phoenix and Fresno just to compare. The summer months for Phoenix are actually pretty close to Fresno during the time of day (12pm-6pm) that I'd be using the swamp cooler. The relative humidity goes down to about 20-25% in both places with the temp from 95-105. Our humidity has wider swings during the day and throughout the year that I'll have to contend with in any project design, but using a swamp cooler when our temps our high and our humidity low might actually help even out the relative humidity in my shop and keep me cooler at the same time.
My workshop is in what appears to be a similar climatic zone to yours, with hot dry summers. I have had a swampy keeping us cool for over 10 years. This is a built in wet pad type with thermostat. I've got a hygrometer which sits at around 40 - 50% thru the summer, & with natural (open door) cooling in spring & autumn & no heating in winter it is fairly uniform all year.
Dondownunder - thanks much for your input. See my reply to Howie also. Based on what you and Howie posted I think I do have a similar situation to yours and that a swamp cooler would probably work the same for me and actually help "level out" the relative humidity in my shop during the hot summer months. Where I'm at has wide swings: high humidity (lots of fog) and 30-40 degree temps in the winter, low humidity (20-25%) and 95-105 temps in the summer. I'm going to be dealing with wood movement and rust prevention whether I use a swamp cooler or not. I've got the shop well insulated, I've got windows I can open, but it's going to be freaking hot in that 12x16 from 12pm-6pm for the 3 months of summer. Thanks again.
Probably rust all yer tools. Fans and cold beer. Knock off about 3:00 pm....
I'd only cool it the same way that you cool the house where the furniture will go. While furniture should always be built to accommodate wood movement, its nicer to start at level similar to its eventual moisture content.
I would like to hear from people who actually have used air conditioners. I thought about a portable air conditioner but you still need to exhaust the hot air out of the shop so I need a hole in the wall somewhere to run the hoses. I live in the same region and right now my solution has been to suspend operations mid-may through early september and spend the time planning the next projects, etc. However, it is hard to stop for three months in a row and just let the tools collect dust. I think that the wood whisperer just installed AC in his Arizona area shop. I tried a portable swamp cooler and it did not work.
Tom - ok, I've got to ask: what was your situation with the portable swamp cooler you tried? What city are you in, how big a shop area, what kind of swamp cooler, what exactly didn't work? I'm guessing that it didn't cool it down enough for you but do you know how many degrees it lowered the temp in your shop? Is your shop insulated? Any additional info would help, and thanks.
I bought a portable swamp cooler from Lowes - it was for a two car garage which is 20 by 24 I believe. I think it did not work because it was not big enough. I placed it in front of an open side door but I think just too much warm air came in - also I did not feel any cooler air unless I was within three feet of it. It just made my the air muggy inside the garage. It may work if there is proper ventilation and air exchange but buying a small portable cooler did not work. I did not feel any difference in temperature. I am in Bakersfield. My shop is insulated. I am very tempted to buy a portable ac unit and try that and have the hoses lead to the area where I now have a vent to let air in - I do not like the idea of cutting a hole in the wall to install a wall mounted unit - I have no windows on the sides of the garage. I have not read enough good reviews or any real lief experience with the portable AC units to make a decision yet.
The best you can expect from a swamper is about 35 to 40-degrees Fahrenheit of drop, and that is if the relative humidity of the incoming air is relatively low. I think that in your instance, it was just pulling air back through itself, and once the relative humidity came up, it couldn't really cool anything.
The secret to a swamper is low relative humidity of the air it's intake air, and a lot of air volume.
Dad had one on the garage in Boulder City, Nevada, which is outside Las Vegas. It was rated at 4500-cfm (whole house size). The garage was well insulated, and 20x25-ft, with nine-foot ceilings, which is 4500 cubic-feet. So he was doing a complete air exchange every minute. If you tried to shut the doors and run it, you never got cool. If he opened the garage door about a foot, and ran the swamper in through the side wall, it would drop the air temp into the seventies and about 65 or 70% relative humidity. Except for the monsoon season in August, when the relative humidity was already around 50 or 60%, and then it just didn't work.
I was house sitting for them one summer, and started leaving the swamper running through the house and out through the upstairs windows, during the day when I was at work, instead of running the air conditioning when I wasn't home. The folks power and water are on one bill from the City. Dad had them set up for direct payment from his bank account, so I never knew what they were. He called up in early August, pissed at me for killing his lawn. He figured that the utility bill was so low I couldn't be watering the grass. By running the swamper, and ac only at night the utility bill was about $100 lower than any he had for the previous three years.
I got a big window unit at Sears when it was on sale; as it is right now:
http://www.sears.com/sr/javasr/product.do?cat=Air+Conditioners&pid=04275281000&vertical=APPL&subcat=Large+Capacity+Units&BV_UseBVCookie=Yes
I ordered it online and they delivered it to my local store for pick-up, no shipping charge. It was made in Korea and is quite a bit sturdier than the Chinese-made ones that Walmart has (I returned one of those).
I cut a hole in the shop wall and mounted it about 6 feet up; it works great. Mine is a 28K BTU unit, but my shop is about 1100 sq. ft.
I use a portable AC that I bought at Fry's. It has an exhaust hose which leads outside through a small hole; similar to a clothes drier. I use it to cool my garage shop in Houston. There are no windows in this garage.
Swamp coolers do not work in the 80%+ humidity here. One benefit to the AC is that it reduces shop humidity somewhat. Another is air filtration.
The unit is rated for 400 sq. ft., but only lowers temperatures about 5 degrees in my uninsulated shop. Still, it blows cold air at my workbench. Perhaps a bigger unit, or more insulation would work better.
Regards,
Dan
I live in El Paso, TX, where the weather conditions are similar to the OP. My previous house had two swamp coolers. They work well on a dry day, but as another poster mentioned, you need to have an opening for air to get out. Since the air is not recirculating like with refridgerated air, you have to have a nice airflow through your shop. Ideally you will want an opening at the opposite side of the shop from the cooler, so that the cool air will flow through the shop. I think putting it in an open doorway will not work. Try blowing into a straw with your finger on the other end. It's hard to get any air to move.
When the house was about 10 years old, I had to replace the coolers and the ductwork because they were crumbling with corrosion. So you'd definitely not want it blowing directly on any tools. Also, if your water is hard, you might get mineral "dust" in the shop.
Last year we built a new house and I got refridgerated air conditioners. Yes, it's more expensive, but it is definitely worth it IMO. I can stay cool even when it rains, and it's just more comfortable.
Here's the Original Poster once again: first of all, the info flowing from my original post has been very welcome and great...it's what I was looking for. Thank you Eric and thank you all! If you read my thoughts halfway through all the posts you know I was leaning towards trying a swamp cooler. As more posts have been added I think where I'm at now is to put in 1 or 2 powerful fans and see how good/bad it is on a 100 degree day. I DO have my 200 sq ft shop well insulated and drywalled so that's a plus...it behooves me to wait and see how lacking in creature comforts it is on a hot 100 degree 25% humidity day. I've got a feeling I'll get to a point down the road where I'll talk myself into breaking down and paying the cost of buying and using an air conditioner, but we'll see. In the meantime, anyone else with success or failure stories involving swamp coolers, fans, or air conditioners for a small shop?
You need to realize that a fan does not cool unless it evaporates -- i.e. when it evaporates the sweat from your brow. Of course it can pull in cooler outside air and exchange the heated inside air.
Tinkerer - yeah I know....it's like I'm pulling a 180 and going from mediocre to good BTU's to none at all, but I could see enough pros and cons with either a swamp or an air conditioner to feel like I should start with just a good shop fan and see what develops. The cons for me for an air conditioner are the expense of buying it and running it and the number of amps it'll take away from my total power in the summer. Like I said, I'll probably break down and get one eventually anyway but I'm still not abandoning the idea of having a swamper. The way I figure the small amount of space in my 12x16 shop might cool down incorporating multiple plans of attack: I've got the insulation with drywall done and that's the most important; good air circulation also won't hurt. The last piece of the puzzle will be what I want in there that actually generates cool air. I think a swamper would actually work since I've got windows on opposite sides where I could set the swamper up next to one to draw in outside air to cool and open the other enough to vent air out. Heck, I've got gable vents high on oppositie walls that I could do the same with if I mounted the swamper 9 feet up next to one of them. That idea intrigued me 'cause I haven't seen or heard of anyone doing that and it would be up where the most hot air is. The cons of a swamper are their efficiency depends on air circulation and the relative humidity....and they generate humidity themselves which my tools and especially my cast iron table saw will not appreciate. Anywho, that pretty much covers my situation at the moment...and like I said, any tales of fellow woodworkers working out this problem or any words of wisdom are welcome.
I bought a used window air conditioner from my brother-in-law and mounted it in a hole cut through the wall. It has to work pretty hard in the hottest part of summer, but will lower the 40'x40' garage workshop temp from 90+ to 75 to 80 with no problem. It also does a great job of sucking the humidity from the air as can be seen by the constant stream of water that drips from it outside. The two bushes below it LOVE it! I believe the unit is a 7500btu rated "AMANA Quiet Zone"
I use a window AC unit in an attached 2-car garage (no cars, only shop). Insulate the attic and garage door and it works great even in 100+ degrees. I can't remember the BTU's (18,000 or 20,000 come to mind) but it is 220V.
The biggest gain insulation wise was to use rigid foam in each and every panel of the overhead garage door. It makes a huge difference, as the south facing aluminum oven (I mean door) would radiate massive amounts of heat in without it.
I start my AC when I walk in the shop and it cools down quickly enough that I don't need to wait before I begin work. On 105 degree days, I may start it 20 or 30 minutes before I go out to work.
K1500 and All:
I live in SW Florida (FT. Myers area) and went to Lowes to check out the 2" ridgid foam insulation. The type they had was covered with a metalic coating (aluminum I presume) surface. Am wondering if I should use this or get the 2" foam without it? Either way the foam is cheap and makes sense to do as I have a south facing overhead garage door.
A post that I read awhile ago mentioned good luck using spray adhesive vs construction adhesive. What have you (and others ?) used to bond it to the door?
My ceiling is insulated but walls aren't (they're concrete block with no windows). Think some day ( I really haven't thought it through much yet) I'll install a mini central A/C unit like the central air in the house. Anyone done that? Wonder if I'd have to insulate the walls over the block to avoid condensation?
I need to do something since it's too hot out there from May to Sept to do much.
Bruce
The metallic layer is a radiant barrier. They work best when the metallic side faces an air space; you don't want it right up against a wall surface. That said, the radiant barrier probably doesn't buy much in your situation unless it's on a wall that gets a lot of sun exposure.
To adhere polystyrene foam insulation, you can use the spray cans of "minimally expanding" foam used to seal around penetrations. Since the insulation is so light in weight, you don't need a lot of strength. You can use the same stuff to seal between and around the edges of the individual panels.
A standard way to insulate concrete block walls is to apply foam insulation as described above, making sure to seal it well (that way, you won't need a separate vapor retarder). Then, build a stud wall in front of that so that you can hang drywall, wood paneling, etc.
-Steve
Steve:
Thanks for the input. Much appreciated. I'll go without the radiant barrier. Haven't used the minimally-expanding foam. I presume that unlike the regular stuff it sets-up more slowly to give me enough time to slide the panels in behind the horizontal bracing (the door is hurricane-rated for up to 130 MPH winds)? There is a 2" space between the door skin and the bracing but not alot of "wiggle" room. I wonder if in sliding it in place it would push the foam out. Guess I'll have to experiment.
Bruce
I've never timed it, but you do have a minute or so to work with. I'd be a little concerned about scraping off too much adhesive. Would it be possible to cut the foam into pieces so that you only have to tuck the edge under the bracing, rather than slide it a long ways? I've only used the spray-foam-as-adhesive technique when I had pretty much full access to the surface that I was insulating (basement/crawlspace wall, inside of rim joist, etc.).
-Steve
Any attempt to "work" expanding foam while it is wet breaks the bubbles and leaves you with extremely expensive and gooey adhesive. You might as well use ordinary construction adhesive.Minimal-expansion foam sets up in the same time, it just expands less. You could slide the foam panels into place first and then punch small holes at intervals and stick the spray foam "straw" through. Don't spray too long in any one place though; too much expansion will break the rigid foam panels or tend to push them out. The stuff can keep expanding for 30 minutes or more.If you have to cut foam into pieces to get it in, a quick shot of foam in the gaps will seal them up pronto.BruceT
Edited 9/2/2007 3:17 pm ET by BruceT999
Bruce/Steve: Thanks for the advise. For my application I think construction adhesive might be my best bet. The foam will be cut into panels 19"X26" to fit within the main bracing on the door. Think I'll also check with the garage door company that installed it just to see what they might use (assuming they retro-fit insulation like I'm trying to do). If there are any gaps after the panels are in place then the slow/low expansion foam applied carefully could seal them...good idea, Bruce T.
Thanks guys.
Bruce
Sorry, I saw this post and HAD to input.I work in a old 1930's car and a half attached garage. Air conditioning? Gee all I wish for is heat in the winter!
>>I work in a old 1930's car and a half attached garage. Air conditioning? Gee all I wish for is heat in the winter!Well, us folks down here in Flowreeda work with the doors open in winter. It's summer that causes problems, and the need for insulation and AC. But I feel your pain - I grew up in Minneapolis.Regards,
Dick in Tampa
I also work in a 1927 Garage, in Central Florida. Working in there for 4 months of the year is simply not possible. I've just installed an air conditioner and am looking to insulate as well. Though I think I'm going to go the spray foam insulation route, http://www.tigerfoam.com. For a little more than using 2" foam panels and multiple cans of spray foam from Home Depot I can "Cocoon" the garage. Which means the spray foam will not only fill the stud cavities but also fill any gaps, holes, etc... It's really easy to do and fast in a square, open space like a garage. When I'm done the whole job will be tighter, easier and though not cheaper, perform better overall longer as I expect it to hold up longer. One of the other main reasons I'm probably going to go this route is to lower the overall humidity in the space. How do you deal with this? Every week I spend at least an hour cleaning rust even though I dutifully cover every surface with Topcote or some other protectant. Working with the tools opens them back up to the humidity and I'm right back to cleaning up rust. Do you have this problem? How do you deal with it?
>>One of the other main reasons I'm probably going to go this route is to lower the overall humidity in the space.>>How do you deal with this? Every week I spend at least an hour cleaning rust even though I dutifully cover every surface with Topcote or some other protectant. Working with the tools opens them back up to the humidity and I'm right back to cleaning up rust. All of my stationary machines with cast iron tops have received a coat of Boeshield T-9, followed by a coat of Johnson's paste wax. I apply another coat of wax every couple of months. After each use, I brush off any saw dust or shavings and cover the metal surface with an old bed sheet. My hand tools live in drawers or terry bags that my wife made for me. I only run the AC when I'm using the shop. I don't have rust problems unless I drip on the tool and don't wipe it up.Regards,
Dick
DickL,
Thanks, except for the Boeshield T9 and the sheet covering I do pretty much what you do. I use Topcote because I can spray and wipe as I close up shop. But, even my chisels closed up in relatively tight drawers and my planes in cotton socks eventually get rust forming on them. I'm going to adopt a cotton covering/sheet and see how well that works. I was initially against it because I thought it would provide a worse environment than leaving the surface open to airing with a coating of Topcote. Thanks,
KWL
On my garage door, I just slid the foam into place and ran a couple of self tapping screws through the frame, into the foam to lock it in place.
The low expansion foam to fill the voids is a good idea though. I might try it before winter gets here.
B Lund,
I did not use the foil faced board, and I am not sure about the properties of it. My door panels have a lip to them and I simply cut the foam a tad oversized to fit and slipped them in. Then I cut thin strips of foam and slipped them into the cracks. This wedged the foam in place and more or less sealed everything up. I would be careful of any method that was not reversible. It is possible to damage a panel (or perhaps the future owners do not want to look at a pink or blue insulated door). I can pop mine out with no damage to the door. If you need an adhesive, consider double sided carpet tape. Also, it just occured to me that there is the potential to add enough weight to the door that it could cause trouble with the springs. I have not disengaged my door to see if it comes crashing down, but it is something to conisder.
Charlie,
I live in the high desert of So. Calif and have used an inexpensive 2 speed swamp cooler in my workshop for several years with good results. According to my humidity guage, about 20 minutes of running the cooler will raise the humidity from a summer mid day typical of 30 % to near 40% and drop the temp about 5 degrees. Doesn't sound too impressive, but actually does make working in summer afternoons bearable. (summer outdoor temps here can run to 110 or more.) One advantage is the ability to apply wood glue during hot dry periods using the cooler. Before buying it, trying to glue during hot dry periods would result in freshly applied glue skinning over before I could get the pieces alligned and clamped. Using the cooler extends this time somewhat. I have noticed no rust problems, but am careful not to place tools directly in front of vent.
Only complaint is, I wish it had 3 speeds; low speed is fine only if I'm working at my bench about 20 ft in front of it. High speed tends to blow away everything not nailed down. My unit was purchased at Home Depot, can't remember brand, remember it was made in Little Rock, Ark. Gary
Hi Charlie,
Fresno. Ouch! My mother grew up in Atwater. I feel your pain. I live on the Southern Oregon coast where the climate is very mild but we will still get the one or two weeks a year where the temps hover around 90. What I have done to help cool my 40x50 shop during this time is install a large window fan on a timer that comes on from 4-6 am filling the shop with cool air. If the nighttime air temp drops enough this could, at least, help augment an air conditioner/ swamp cooler. Otherwise, insulate till your blue in the face. Good luck
Paul
Swamp coolers.. Not Californian but in Central Texas (As in Fort Hood Texas) where I 'lived?' a bit. I had a swamp cooler in the house.. Kept us cool till the furry caterpillars clogged up the vents!
Swamp coolers just evaporate water and I never remembered any excess humidity inside the house (shack). In these MODERN time I'd suggest asking a local contractor about it if you are serious about it.
DAMN! Without the spell checker I'd be more of a Idiot!
Hello Charlie,
I grewup in West Texas. All we had was a swamp cooler, but with the low humidity, the cool wet air was a blessing. But, when we had rain storms, the house and bed sheets were as damp as a washcloth!!! Hard to sleep on damp and sticky nights like those.
I now live in North Central Texas where the humidity is much, much higher. When we bought our first house, I put in a swamp cooler....the newspaper and typing paper in the house felt like an old washcloth, and made no noise when wadded-up, because things were so damp. Dried it down, wiped it clean, and took the cooler back to Sears...
In summer of 2000, we upgraded our home's central HVAC. The high efficiency Pulse heat and two speed compressor, 1985 model, Lennox heating (Propane) and cooling system was still working. Although a bit twitchy, the whole system was still working, plus the heating system has a full LIFETIME REPLACEMENT WARRANTY.... The Trane installer said he would install the old Central system in a corner closet in my workshop for $200 if I bought the new house system...!!! The workshop has been a dream ever since...especially with a programmable thermostat! In winter, it will easily keep it just warm enough to let your finish dry smoothly and completely. On those cold windy icy/snowy mornings, the shop automatically comes up to warm temperature, and as far as comfort, going from the house to the workshop is as though you were walking from the den to the kitchen. In the summer, the compressor is wired to run only on low speed compressor since its size was for a 2,000 sq.ft house and now in an 1,100 sq.ft workshop.
The key to keeping the workshop at an affordable climate, winter or summer, is insulation, insulation, insulation!!!! Put in all the insulation you can, and don't forget super insulating windows and doors. If your woodshop budget is like mine, covering the old single pane windows with insulating drapes and adding a storm door can help a lot. My workshop should be 1,200 sq. ft., but with 6" insulation on the South and East walls, and 12" of insulation on the North and West walls, I'm guessing I've lost 100 sq. ft.
Lastly, running the system in the winter at 68 degrees keeps you from sweating as you work, and in the summer I'll keep the temp. at 78 because it is cool, plus the system takes out all the humidity. I run two 48" ceiling fans to stir the air; they have three speeds and reverse. I'll run them on high in summer and on the lowest speed with one reversed during the winter.
Check out your local air conditioning businesses for working "Take Outs" before adding a Swamp Cooler... Good Luck
Bill
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