Weird A/C question..

[GRUMPA]

I was (trying) to run the lathe this morning at 7am out in the shop. Running the lathe was the easy part, what wasn't was the beads of sweat getting in my eyes, nasty. So I looked at the inside shop thermometer and it read 90deg and by now it was 7:30am.

So I ventured into the house and started looking for a/c units. Much to my surprise.....all I need was a 5000BTU unit for my modest 10x12 shop. Now the fun begins......I don't want a window unit, I want a wall mount unit. After some looking it seems once you hit the filter to whittle down the choices, the smallest wall mount unit they offer is a 8K unit, or there abouts.

Living on solar has it's perks, but convenience isn't one of them. I need a unit that sips the amperage so I wont have to run a generator. The 5K units draw to there rating 4.8 amps which I can live with. Once you go beyond the 5K BTU mark the amperage increases more than I want.

So here's the question: What do folks do when they want a small wall mount a/c but can only find the window mount? Just use a window mount a/c and mount those in the wall?

With my system it creates a real pure sine wave and 62Hz. I use a swamp cooler for house cooling which does OK but the humidity right now is 58% with the house temp at 68 and outside it's 87. The unit itself has a label that gives the amp usage on low at 5amps and high at 7amps. With our system it uses 2amps on low and 3amps on high..

[dragon813gt]

Have you looked at ductless split units? Mitsubishi is the biggest name in that game. They have very low amp draws because their compressors are inverters and only ramp up when required. They make a variety of air handlers to meet your needs. But the most common is a wall mount. Which in the size you need will have a very small footprint.

[oneokie]

I helped put a window unit in a wall, so this is what was done; a hole the size of the window unit outer case was framed in the wall with enough tilt for the unit to drain.

[dragon813gt]

I helped put a window unit in a wall, so this is what was done; a hole the size of the window unit outer case was framed in the wall with enough tilt for the unit to drain.

This is a fairly common practice but can creat problems when it comes time for replacement. There is no standard size so more carpentry will most likely be required.

I should have asked. Are you looking for a self contained unit that you can install yourself? Or are you looking for the best option that may require a professional install.

[altheating]

Grumpa, look at the online directions for the unit you are looking at. I installed a 28,000 BTU unit last week. It was listed as a window unit. I could not locate a specific thru the wall model and after reading install install manuals online, much to my surprise the directions also showed how to install it through the wall. I installed it to cool a 10 x40 shop inside my 30 x 40 garage. It cools the whole garage to a point, but in the partitioned off shop you can cool meat! Worse case you need to buy a wall thimble to install the window units.

[GRUMPA]

This is a fairly common practice but can creat problems when it comes time for replacement. There is no standard size so more carpentry will most likely be required.

I should have asked. Are you looking for a self contained unit that you can install yourself? Or are you looking for the best option that may require a professional install.

For what I want, a self contained system would be more than adequate. I don't want a split system with all the critters we have here. The wife and I did most of the building here so carpentry skills (or lack thereof) are right up our alley. We like to live the simple life, so the more basic things are the better we feel about it...

[Fishman]

The little window units sure are inexpensive and do a fine job in small spaces. For the difference in cost and easy availability, a bit of carpentry work that may or may not be required 5 years or more in the future seems like a good trade. May be a good opportunity to put in a small window too.

[Petrol & Powder]

Without getting into all the specs for the power/BTU's etc. , I think the simplest solution would be a small window unit mounted into an opening in the wall.

[dilly]

My shop (lofted shed) has a window unit mounted up high and out of the way through the wall. The loft is wraparound and the cold air just falls to the bottom where I work; keeps the shed very comfortable. It is also high enough to be a smaller risk for burglary, and doesn't make any intolerable cold spots where the air is blowing. Indoors we have a mini split; it's nice but unless you have the skills and tools to work with the refrigerant line you are looking at professional installation, and the expense is way more anyway. The advantage is that the heat pumps can usually heat a room as well when required, and they are also WAY quieter. Having the window unit in the loft also helps with the noise.

[labradigger1]

If you have an abundance of water you could use a swamp cooler
Lab

[Echo]

If you have an abundance of water you could use a swamp cooler
Lab
He's in the AZ desert - a swamp cooler would work fine, except in our monsoon season that just started. The humidity (dew point) is so high that little actual cooling takes place (not much evaporation in an already-moisture-laden air, just an increase in humidity). Then it's moist heat, not a dry heat, and no fun, as he attested to.

[dilly]

Not only that but the extra moisture will promote rust on any tooling in the shop.

[GRUMPA]

Swamp cooler and my shop wont play nice with each other. I have more tools in there than I know about, and....I have all the electronics associated with solar power.

143033

143034

That's just 1 of 2 inverters I have in the shop, the other 1 powers the shop while the 1 in the picture supplies power to the house. And I have another disconnect for it as well. I picked up the other inverter pretty cheap last year, so I got it and wired it up so that "IF" 1 fails a simple 16" jumper wire is all it takes and I'm up and running again.

[SeabeeMan]

http://www.amazon.com/Frigidaire-FRA053PU1-000-Portable-Conditioner/dp/B004P8K39G

How about something like this portable 5000 btu unit? We don't have central air so we have a 12,000 BTU unit like this in our bedroom. We run it for 1/2 hour before bed in our 12x12 bedroom and it does great. 1 or 2 days a year we roll it out into the living room/kitchen upstairs and just runs all day, but that is only when we can't cool the house back down at night when it stays about 75.

You just need a window to put the ducting in.

[GRUMPA]

That unit...according to the specs uses almost double the amps a window unit uses. I'm just going through right now reading up on them. The ones they have locally ( 116 mile round trip) use 4.8 amps and I hope with my system it'll use less than that.

[farmerjim]

I have a 5,000 btu window unit mounted through the wall in the back office in my barn. Make the hole several inches larger than ir needs to be and close it down to the needed size with screws, then when it breaks and the replacements that you find are larger than the old unit, just remove the extra framing. This worked for me when it happened several years ago.

[dilly]

The more efficiently a unit exhausts hot air, the less energy it will use. Those portable ones seem like a poor solution with their little hoses to go out the window. So much of that heat will leak back into the room, and you will still have to cut a hole for exhaust while taking up precious shop square footage.

I might be the least handy guy on this board and cutting a hole for the A.C. is something I could handle.

P.S. I don't know how critters could cause any trouble with a mini split. You may be misinformed about what a mini split is or how they work, or perhaps I'm not aware of your local fauna and associated hazards. I mounted my outdoor compressor to the wall overhead, and the whole to get the coolant outdoors is less than 3 inches.

[bangerjim]

Just do as I do and use a 8 to 9K BTU WINDOW unit stuck in a hole in the wall. Brings my 10x12 shop down from 99 to 76F in <30 minutes. I have R32 in the ceilings and R22-ish in the walls with 2" thick styro on the doors.

Works for me in our desert heat. And I just added a 32" ceiling fan to move the air better. Really helps.

bangerjim

[Mk42gunner]

It has been so long since I was doing heating, a/c and appliance repair that I have forgotten most of what I did know about BTU sizing. What I would do is get the 5,00 BTU window unit and install it through the wall, up fairly high.

The new window units come with a remote control that you can specify what temperature you want it to cool to; not just high, medium and low like thirty years ago.

The suggestion to use a ceiling fan to help circulate the cooler air makes sense; if you can support it with your solar setup, and have the headroom.

Robert

[leadman]

Been thinking of a window unit for my garage also. Have a large swamp cooler on it now but it did not work so good yesterday. My problem is my garage only has one set of old style windows in it. Metal frames about 1' on a side with 2 tall crank out windows on each side. I will have to cut thru the block wall to add an a/c unit.Plus insulate the garage door.

For the OPers problem a small window unit should work well. I would do it even if I had to run a generator to top the batteries up.

[GRUMPA]

Been giving it some thought yesterday and today. Yesterday it got up to 94deg so later on I opened the window to cool the shop after the sun went down. Today at 7:30am when I went in there it was 78deg and at 8:30am it went to 82deg. This shop is only 10x12 with exposed rafters, but I have R-19 insulation throughout the shop. Keep in mind I have about 1.5K Lbs of lead batteries in there that are 94deg right now and we all know how well lead retains the heat. Those batteries are in there own 2" thick foam insulated box with a vent for the gasses. Plus I have a lot of metals in the way of hardware and machines.

I looked around the shop and I only have 1 place I can put it, up high. Looks like I'll go to the local home improvement store tomorrow and pick up what I need (or think I need) and put the unit in during the week. I'm really hoping this will solve some of my problems working out in the shop. Believe it or not, I had a spider walk across the circuit board and fry it, and that was the a/c for the house in Phoenix, that cost a pretty penny to fix.

[popper]

Just use a window mount a/c and mount those in the wall, put a small efficient computer fan to blow cooled air across the batteries.

[jonp]

How about a movable unit? Sits on the floor they work ok. When you want it inside just unplug and roll it in

[GRUMPA]

Just use a window mount a/c and mount those in the wall, put a small efficient computer fan to blow cooled air across the batteries.

Batteries work best when right around 80deg, if you cool them down to much they wont hold as much power. That generally wont happen till they reach, oh say........60deg or so. And putting anything like a fan close to a battery bank....... the Hydrogen gasses that batteries omit might create a flash fire.


How about a movable unit? Sits on the floor they work ok. When you want it inside just unplug and roll it in

Looked at the movable type, they use more power, which.....I have to be conservative with..

[jonp]

Just use a window mount a/c and mount those in the wall, put a small efficient computer fan to blow cooled air across the batteries.
A small solar powered attic fan on the opposite side of the room will move air nicely

[jsizemore]

It's easier to make a hole smaller then bigger. I've got a 12,000btu window A/C to keep my 625 sqft cooled in central NC. It's up high, the top is 12" from the 8' ceiling. It was a bear to remove the 18 year old unit but the new scroll compressor unit was a breeze. Remote control makes changes easy since the A/C is behind the stereo.

[pretzelxx]

The Mitsubishi split ac works wonders. We had them in Afghanistan and let me tell you. 65 inside 112 outside.

[GRUMPA]

The Mitsubishi split ac works wonders. We had them in Afghanistan and let me tell you. 65 inside 112 outside.

Just how big of a solar array do you think I have?

[dragon813gt]

Just how big of a solar array do you think I have?

They draw less power than a window shaker. Issue is the boards like to fail and they're not cheap. They are more money and require professional installation but are a lot more efficient and make almost no sound.

[GRUMPA]

The ones I'm looking at are 110v and they rate them at a 4.8 amp draw. Equals about 475Wts

Split system Mitsubishi the smallest I can find is a 220v and uses 6.4 each leg. Equals 1390Wts

http://bizow.com/models/air-conditioner/mitsubishi/srf50zjx-s.html

[dragon813gt]

They make 115v models. But they are bigger units. The smallest is 8.5k and it's rated at 870 watts. Advantage is that they're a lot more efficient. For your application a window unit mounted in the wall is your best option.

A 220V 9k btu unit is rated at 690 watts. I know you're concerned about total power draw. Those are the max ratings. I rarely see them pull over 4A when it's just one indoor/outdoor. And that's both units combined because they're a single point connection.

[MaryB]

Moved my battery bank into my temp controlled living room. It masquerades as a large bench that I drop a piece of masonite on top when I want to cut leather. In summer it used to get to 100 degrees, winter it got as low as 20... now it sits around 65-80 degrees year round and uses a lot less water.

[lksmith]

El cheapo wally world unit for $100-120 is about 5k BTU.
I have two of them and draw is 585 watts.
Cools my 8x12 load shop pretty well here even with 100deg and 100% humidity

[GRUMPA]

Got the unit yesterday and got it hooked up and running. Much to my surprise it's drawing 3.45 amps at 114v so the total wattage is 393 watts. Now that I can live with....

[Mk42gunner]

Got the unit yesterday and got it hooked up and running. Much to my surprise it's drawing 3.45 amps at 114v so the total wattage is 393 watts. Now that I can live with....

But the important question is, How is it cooling?

Robert

[GRUMPA]

I had the thermometer resting right on the vent, air coming out is 48deg and the shop was 82deg. About an hour later the shop was 75-76deg and was an absolute blessing being able to work out in the shop without breaking a sweat. Right now it's off since I'm equalizing the batteries today, and in a 1/2hr it went up to 84deg. But keep in mind I have over 1K Lbs of lead in the form of batteries at 94deg right now..