Home Forums Hunting & Shooting Hunter's Campfire What Size A/C

Well guys the dog days of summer are almost upon us and I would like to install a window air conditioner in my workshop.It is insulated and constructed of 2X4s. Measuring 12x28X9 that works out to about 3024 cubic feet.What size unit would it take to keep my beer and I cold.Comments please.

Biggest one you can hang, hell that big a space needs a central unit, it's almost twice the size of my house!!!!

OOPS, my mistake, I thought SQUARE FEET, with what you have I would say a 5,000 BTU unit would fix ya right up.

Air-condioners are (or used to be) rated in terms of how big a block of ice would equal one's cooling capacity. This has always made me think of a poor hound puppy that my great-uncle Shep had when he was a boy in the late 1800s.

My great-grandmother had come down with something bad, and the doctor had prescribed ice packs (perhaps influenced by the fact that an icehouse had gone into business in the next county over).

While someone drove the wagon over to get a huge block of ice, others on the place built a lean-to against the shady wall of the barn and made a nest of sawdust in it for the block of ice. When the wagon got back with the ice � wrapped in layer upon layer of burlap � they all hove-to and wrestled it into the nest of sawdust and covered it with a deep layer of sawdust.

Each day, someone brushed the sawdust cover aside, laid-back the top layers of burlap, and chipped ice out of the top of the block for great-granny's ice pack, then covered the block with the burlap and sawdust again � leaving, of course, an ever deeper crater in the top of the block.

One particularly hot, muggy day, Uncle Shep's hound pup came panting and plodding 'round to the shady side of the barn to find a relatively cool spot to lie down. He felt the fringe of coolness near the block of ice and spotted the deeper shade between the block of ice and the shed roof of the lean-to.

He hopped up there and curled-up in the sawdust that by then formed a depression above the block of ice.

When someone found him later, he was shivering violently and "bearing down" harder and deeper into that sawdust.

Where'd all that heat wave go?

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In a typical residence, you size the central unit to be about 1 ton of A/C per 400 - 500 square feet. You're at 336 sq. ft. ... but you are wanting to do a window unit I guess ... so you'd need to figure the BTU's that a 1 ton A/C puts out, then get a window unit that puts out about 3/4 that much ... then you can make sure that in the hottest of the hot, you're still cool.

Ken,

So a 4-ton rated unit means it has as much cooling as 4 tons of ice?

284LUVR, 12,000 BTU's equal 1 ton of cooling capacity. In my first home my living room was 14x28 and I put in a 18,000 BTU unit. and let me tell you I could stay really chilly if I could keep my wife away from the controls. larry

As a boy, my Dad would deliver ice blocks to homes and apartment residences for the ice boxes. He tells of one particular heat wave when he would haul a 50 pound block of ice up eight flights and be able to slip it under the door--it was so hot!


--Mike

Have not been here in a long while since I purchased a business back in January, but as your luck would have it one part of my endevor is HVAC in PA.

To get to the quick of it with the dimentions you give and being in PA I would recommend apx 16,000 BTU window unit.

12000 BTUH equals one ton.
A modest size blue collar home usually takes a 2.5 ton central unit.
Almost all town houses take a two ton.
A very large residential home may use up to five tons. Two story houses can be a pain because all the cold falls down to the basement so air circulation is important. A window unit has fairly poor air circulation so all things being equal I kinda like to go up in size.

The scientific way to do it is to crunch engineering style numbers and do the algebra, and it is all laid out on what is known as a "J" Manual. Any competenent AC contractor estimator should be able to spit out a computerized J manual survey for you with an estimate. The J manual takes into account infiltration air, the R value of the walls and cieling, the local area peak days, the glass windows, etc. Also you must take into account if you have a proper vapor barrier and the humidity you face.

If you mount the window unit as high as you can in the wall you will get much better air circulation. The cold air will blow out and fall and stir the room. If you can try and direct it along the cieling it may mitigate some annoying drafts. But maybe not.

You could call a contractor and ask for an estimate for a split system sanyo, a central system and a commercial window unit. The contractor ought to do the J manual and give you three estimates with it all broken down as to size btu's etc.
That estimate ought to be free. Then you know from the hard math what size.

If you go too large you will not have enough run time to dehumidify properly. If you go too small it will not keep up on a very hot day. It should be "just right"

Also you have to take into account available power supply and the condensate drain arrangement.

The split systems are very nice but pricey. They keep you from having to have a hole in the wall which makes the place more secure. Sometimes thieves focus on the window unit as a way of entry. The sanyo's are expensive though but they sure are nice, and they are much quieter in the shop because the condenser is not right there on the wall but outside on the ground. They are also called ductless split systems. Other people make them too


Or you can ignore all this and put in a one ton unit and hope for the best. Which is probably what I would do.