Replies

1. 
   TomT226 | Jul 05, 2005 01:36pm | #1

   Check over at Breaktime.  They have a lot of HVAC guys that might give you some good advise. 

   I have the same problem.  My shop has 2-10' garage doors in front and a carport.  When it gets too hot, I just roll the saw, DC, planer, BS, outside and work.  I also have 3 or 4 hollowcore Luan doors that I mount on sawhorses for sanding and assembly.  Real light.  It was 102 here in Central Texas at 3:00 PM.  Sweatin' like a feral hog.....

2. 
   ring | Jul 05, 2005 03:11pm | #2

   hi BM,

   We've been hounded by the problem for a long time.  Our shop in Israel has AC in the office and showroom, as well as the painting room which is a closed area.  But the main shop area is not feasible to AC within our budget.  Every machine has its dust collection, but the shop still has too much dust for regular systems, and would need a large filter to make it work.  The shop area is about 3000 sq.ft.  Until now the cost just seems impossibly high, so we suffer a bit, and just go to the beach when it gets really unbearable.

   regards,

   DR

3. 
   jackplane | Jul 05, 2005 04:06pm | #3

   The amount of BTUs you'll need to cool your shop depends on ceiling ht, insulation, mean temp, sq ft, southern exposure, etc. These factors are called a 'J rating'.

   That said, a minimum 10k BTu ac should help; I like the ones with a washable filter and that run on 110/120v. Also think about a roof fan to draw out the hot air.

    

4. 
   Kell | Jul 05, 2005 04:11pm | #4

   Hey Brian,

   For what it's worth, I've got two window units in my 20 x 30 foot shop, each about 6,000 BTUs.  The ceiling is insulated and all but one wall are as well.  These two units are able to keep the temp under 78 degrees farenheit.  I also run a separate dehumidifier to assist.  I just knock the filters off every couple of weeks, more often when sanding.

   Kell

5. 
   DougF | Jul 05, 2005 05:52pm | #5

   I've got a 20 x 35' shop that is very well insulated with 8' ceilings.  The single window unit copes fairly well with the Dallas heat as long as I keep the cooling fins clear of dust. 

6. 
   IanC | Jul 05, 2005 06:11pm | #6

   I found that the suction at the grill will hold a thin piece of foam filter material in place on the front of a window unit, sort of a pre-filter.  It's a visible reminder to clean the filter and keeps alot of dust from getting to the main filter.  10,000 BTU does a fair job in a well insulated 20 x 30 building if I start it up early in the day.  Once the shop is in the 90's, forget it. 

1. 
   brianmexico | Jul 05, 2005 07:17pm | #7

   Does anybody have the formula for calculating how many BTU's would be required for my shop. My shop is about 18x24x10 high. It would seem to me that it would need at the very least 1 ton of cooling capacity (14,000 BTU). I have solid concrete walls and a fairly well insulated ceiling with no windows and only two doors (no it's not a prison cell). Temperatures here in the summer can go above 120 degrees and the humidity is high.

   Brian

1. 
   BG | Jul 06, 2005 12:30am | #8

   Brianmexico,
   You should have more than enough with 14,000 BTU's...you could probably get away with a 12,000 BTU unit. The big heat/cool impact is air changes per hour and windows(80 btu's per square foot). Niether of those factors are much of an issue for you. 

1. 
   brianmexico | Jul 06, 2005 05:23am | #9

   Thanks for the advise everyone, I'm heading down to Costco tomorrow to pick up a Carrier that they have at a good price. 15,000 btu split unit with the compressor outside and the blower inside.

   Brian

2. 
   BarryO | Jul 06, 2005 12:43pm | #10

   Does anybody have the formula for calculating how many BTU's would be required for my shop.

   Do a Google on "air conditioner calculator" and you'll get plenty of hits.  The most comprehensive ones ask for room dimensions, your location, linear feet of wall in each compass direction, insulation, square footage of windows in each compass direction, etc.

   I went through this a couple of weeks ago.   I'm expecting a 24,000 BTU wall unit to be delivered in a couple of days. ;)

   The min-splits are very nice, very quiet, but can be pricey.  I just got a window/wall unit because in the shop I really don't care about noise, and since I'm not using this full-time I don't need the ultimate in energy efficiency, either.

7. 
   DaveBarker | Jul 06, 2005 03:32pm | #11

   One thing that really helps is an attic fan. My shop used to get 10-15 degrees hotter than outside temp in summer. Since installing an attic fan it (at least) gets no hotter than outside temp. Of course I have an open attic with no insulation, so it's no wonder it got so hot...

   Dave