How to air condition a shop?

[Brian Elfert]

I know radiant heat would be the best heat source for a shop so I don't have to deal with plugged filters and such.

What is the best way to air condition a shop? I would like to avoid plugged filters if ppossible, but most of all would not want to plug the indoor coil. Do I just have a regular system installed and change the filters often?

Here in Minnesota we don't need to A/C for too long, but when we need it, we need it. It can get to 90 degrees with a 80 degree dewpoint and stay there for days on end. Besides not being able to work in the shop, I'm sure the humidity isn't the best for the tools.

On edit: What about 100% outside air? Is that a good idea or just a waste of energy for a non-problem?

Brian Elfert

[Dick Latshaw]

Here in Minnesota we don't need to A/C for too long, but when we need it, we need it.
C'mon, Brian. I know for a fact it never gets above 50 in Minnesota. (Just kidding - I grew up in Mpls).

Down here in Floreeda, where it's REALLY hot and humid for a good part of the year, I've got a 12000 BTU window unit with a standard pleated AC filter taped in front on the air intake. It collects a fair amount of fine dust, but does a good job. I do have a Dust Gorilla attached to the large machines and a Fein vac for small and portable tools. I also blow out the shop about once a week.

[Jim Becker]

I also use a window unit in my shop here in SE PA where it gets "stinky-sticky" during the summer. I just try and clean the thing frequently. Unlike Dick, I don't have any additional filtration on mine.

[Bill Simmeth]

I went with a mini-split system (outdoor compressor, indoor condensor). It has woven filters like most dehumdifiers. I'm real religious about washing them every week and vacuuming the coils. Heat in winter (a little milder here than Minnesota) and A/C in summer. Life is good.

[Jeff Wright]

I recently installed a mini-split system that provides cooling, heating and dehumidification in my 2-car garage here in the west central part of florida. I live on the water so humidity was a big concern as far as tool rust. So far so good, and that is without any ceiling insulation and open soffits - I hope to get around to insulating one day soon, but so far the electric bill has not shown any shocking numbers. It has a remote control and is a one ton unit. The inside unit is mounted high on the outside wall and the compressor is outside. It is VERY quiet. It cost about $1,600 installed and uses a 220 line. Not sure how satisfactory the heating component would work in Wisconsin however. Mini-splits I'm told have been used in Europe for over 15 years with great success. The units are ideal for remote rooms in a house where connecting to the main HVAC system would be prohibitively expensive.

[Brian Elfert]

I'm thinking my shop might be as large as 1,000 square feet or more so I don't know if a window air or mini-split will cut it. Although, my house has a pretty small A/C unit for over 2,000 square feet WELL insulated.

I wonder if two mini-splits would be less expensive than a real A/C system if I use radiant heat?

I'm strongly considering geothermal heating/cooling for the house and probably the shop too, so I may need a real ducted A/C system anyhow for the shop.

Brian Elfert

[Thomas Canfield]

Brian,

My shop is 22x24 with 10' walls and peak ceiling of 14'. I have a 2 ton house type air conditioner with electric heat strip air handler system. The unit sits to one side of the shop on a raised platform with additional filters (2 now and room for third) on the side walls. That catches most of the dust ahead of the normal filter that is under the unit. I have not had any accumulation of dust on the coils. I did not install any duct work but only a plentum with registers on the outlet and that has worked well to keep the shop comfortable. I do run a small fan to circulate air at times since my normal temperture control is 60 F for heating and 80 F for cooling. The electric bills have not been too bad, but the electric heat is expensive here and would be much worse there. Check out the pictures in the 8-9-04 post I did on similar subject.

[Dave Richards]

Brian, my shop is in our attached two car garage. Fortunately I don't have to share it with the cars. For the last few years I've been putting up 2" think pink foam insulation over the large door in the winter which helps quite a lot. Last spring I just left it in place and ended up leaving it all summer. The walls and attic are insulated but the exterior walls are only 2x4 studwalls so the insulation is only about 3 1/2" of fiberglass.

Last summer, even on the hottest days, I never saw the temperature more than 80°. The thermometer hangs above the exterior service door so that was the temp at about 8' off the floor. I managed to be quite comfortable with a simple box fan sitting on the floor circulating the air.

I'm sure I'd like air conditioning in my shop but since I've been keeping the big door closed it hasn't really been a problem.

[Al Willits]

You guys have to remember, here in Minn the average temp for the year is in the 40's, so 90 is a killer for us up here in snowland...:D

Mini splits get pretty big so they might work, personally I'd run a air handler and a standard A/C unit, then I would use multiple filters but not in a row, I'd run them side by side so you had a large area for filtering, restricted airflow and A/C doesn't work well and can slug a compressor, that's liquid freon getting back to the compressor.
I'd also see if I could find a R-22 unit, cheaper and we'll have 22 for quite awhile for repairs.

You near the Twin Cities?
I work for Center Point Energy and we sell the Samsung Mini, I could prob fax or send ya some info so ya at least can see what they're about.
But I think the mini won't deal with the sawdust well, filtering isn't one of their high points.
Al

[Rob Will]

I'm installing my old Lennox Pulse Furnace (sealed combustion) in the shop along with a 3 ton condensing unit outside. The furnace is protected by a Spacegaurd pleated air filter. The return air plenum will have 3 filter grilles where I can install 3 washable (or cheap throw-away) pre filters. That should extend the life of the Spacegaurd media.

[Al Willits]

Rob, be careful with the pulse, Lennox had a problem with the chambers on some of them, and put out a advisory to have those pressure checked on a regular basis.

Maybe check here for details
http://www.inspect-ny.com/heat/lennox1.htm

Al