Shop AC

Thanks for all the input guys. I know my situation isn't optimal without insulation, but at least the area is fairly well sealed. All of the exterior siding is older 1" thick wood from the 60's and every joint and lap is caulked, plus a layer of tar paper. I have plans to renovate and expand in the next few years which would involve stripping this building to the frame or completely rebuilding it. I am just looking for some help in the few months with extreme temps in the interim. Its pretty unbearable out there from now through late September. In the winter during the very few days that the temps get down into the high 20's or low 30's, I am able to push the temps up into the 50's with a small electric heater. This really takes the edge off and makes being out there much more enjoyable. I was hoping that installing a small AC unit would do the same for the dog days of summer. Again, only when I am planning on spending some time out there in the evenings or on weekends, not to run continuously. Additionally, by keeping the garage door closed, it would hopefully eliminate the pesky mosquitos that seem to fill the place as soon as I open up all the doors and windows.

If I do try it I will report back with the results. At this time of year, I should know pretty quickly if it will work or not.

Brad
 
I am in Sacramento, and the next week or so is forecast to be 100-105F every day. My shop is not insulated, and is not heated or cooled. If I want to do some work in hot weather I get out there very early in the morning when it is relatively cool and quit when it gets too warm. It usually cools down well overnight here, and the humidity is usually very low, essentially a desert with irrigation and a sea breeze most evenings (but not expected this coming week.) Of course, I am retired and can play in the shop when I want to. I set the schedule...
 
Thanks for all the input guys. I know my situation isn't optimal without insulation, but at least the area is fairly well sealed. All of the exterior siding is older 1" thick wood from the 60's and every joint and lap is caulked, plus a layer of tar paper. I have plans to renovate and expand in the next few years which would involve stripping this building to the frame or completely rebuilding it. I am just looking for some help in the few months with extreme temps in the interim. Its pretty unbearable out there from now through late September. In the winter during the very few days that the temps get down into the high 20's or low 30's, I am able to push the temps up into the 50's with a small electric heater. This really takes the edge off and makes being out there much more enjoyable. I was hoping that installing a small AC unit would do the same for the dog days of summer. Again, only when I am planning on spending some time out there in the evenings or on weekends, not to run continuously. Additionally, by keeping the garage door closed, it would hopefully eliminate the pesky mosquitos that seem to fill the place as soon as I open up all the doors and windows.

If I do try it I will report back with the results. At this time of year, I should know pretty quickly if it will work or not.
Brad

Buy the biggest one you can and use it in your rentavation afterwards
 
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Something is not right with some numbers. 18 tons is a HUGE amount of refrigeration.

1 Ton of refrigeration = 12,000 BTU/hr

My central heat pump is a 4 ton capacity.

Consider a portable A/C unit. This style has a flexible duct to vent the warm exhaust air to an outside window. With this style you can move the unit closer to where you are working. You may feel cooler even if the overall room is warmer.



Actually it is the cooling capacity of 1 ton of ice rounded with a few assumptions. Goes back over 100 yrs or so. So one can also deduce it takes 6 x the energy to melt ice than to raise water 1 deg
 
As an update, I did purchase and install a 18,000 BTU Cooling/ 16,000BTU heating unit. So far it seems to be serving the intended purpose. Its not an optimal set up without a fully insulated envelope, but it works ok. I framed an opening and utilized a through the wall installation. Subsequently I added insulation in the east and west facing walls and have also insulated the north facing double garage door. The south wall is not yet insulated and the ceiling is open to the rafters. Adding insulation to the walls hasn't seemed to make much difference. However, insulating the metal garage door did seem to provide a noticeable improvement. I will probably finish insulating the last (south) wall, but I will have to temporarily move and then re-level my lathe to do so :dread:. However, I really don't see it making much difference unless I enclose and/or insulate the ceiling.

I have not really tested the set up to full capacity and not yet left the unit running for more than a few hours. I have it installed such that I can focus the airflow in the area which I am working. I have come home from work early a few times and fired it up in the full heat of the afternoon when the inside temperature was around 97 degrees. Within a half hour it creates a workable less humid environment with a cool dry breeze. Its kind of like being in your car in the middle of the summer with the AC on high. It definitely beats a 97 degree furnace with high humidity and mosquitos eating me alive. In the evenings, I can turn it on and get it into the high 70's pretty quickly. I have not tried to push it more than that.

The next size larger unit would have been a better choice, but this was the largest I could use given my electrical imitations. That is unless I skipped the heating feature as the AC only units require less amperage. Overall, I think it works better than the portable AC unit I was previously considering.

Thanks for everyone's input and suggestions.

Brad
 
Your first effort at insulation should be the ceiling. Eighty percent of your heat loss in the winter goes through your roof. An equivalent amount of heat is radiated through that roof in the summer. Walls, windows and doors only account for @ 10 percent.

Randy
 
As an update, I did purchase and install a 18,000 BTU Cooling/ 16,000BTU heating unit. So far it seems to be serving the intended purpose. Its not an optimal set up without a fully insulated envelope, but it works ok. I framed an opening and utilized a through the wall installation. Subsequently I added insulation in the east and west facing walls and have also insulated the north facing double garage door. The south wall is not yet insulated and the ceiling is open to the rafters. Adding insulation to the walls hasn't seemed to make much difference. However, insulating the metal garage door did seem to provide a noticeable improvement. I will probably finish insulating the last (south) wall, but I will have to temporarily move and then re-level my lathe to do so :dread:. However, I really don't see it making much difference unless I enclose and/or insulate the ceiling.

I have not really tested the set up to full capacity and not yet left the unit running for more than a few hours. I have it installed such that I can focus the airflow in the area which I am working. I have come home from work early a few times and fired it up in the full heat of the afternoon when the inside temperature was around 97 degrees. Within a half hour it creates a workable less humid environment with a cool dry breeze. Its kind of like being in your car in the middle of the summer with the AC on high. It definitely beats a 97 degree furnace with high humidity and mosquitos eating me alive. In the evenings, I can turn it on and get it into the high 70's pretty quickly. I have not tried to push it more than that.

The next size larger unit would have been a better choice, but this was the largest I could use given my electrical imitations. That is unless I skipped the heating feature as the AC only units require less amperage. Overall, I think it works better than the portable AC unit I was previously considering.

Thanks for everyone's input and suggestions.

Brad

I had the same situation in my shop. It’s smaller 14 x 20. Put in the window unit and discovered it just didn’t work well. Insulated walls. Put in foam board for the ceiling with insulation hung over the rafters in the center. Not the best set up. But easiest to do in the shop around machines.

This works well. This February when I needed heat I started the ceramic heater hit the propane space heater to warm it up. The temperature got up to a comfortable quickly. Then as it got warmer the summer the window AC works well.

Moral is to insulate especially the ceiling. It doesn’t have to be fancy


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