Window a/c vs Portable a/c

[fourspeed61]

Hi all,
My metal building is 18w x 26d x 12h with 1 inch spray foam insulation on all walls and ceiling. The window that I wanted to install an a/c unit in is 26" wide but the sliding window only goes up 13" which limits the BTU size to only 8000.
Therefore, I'm thinking about a portable a/c unit but have no clue what size BTU would give sufficient cooling. I'm comfortable working in my shop at around 75 deg - 80 deg. I know there are all kinds of a/c out there like mini-splits, etc but what to keep the cost down. Anyone out there have a similar workshop as mine and use a portable a/c unit Thank you....Mike

 

[EOC_Jason]

What about those portable ones that you can cart around that have a flex-duct you run to a window?

 

[b-boy]

Can you make the window open any taller. My bedroom widow has a similar problem. Mine has removable stops, so I can get an extra 3"-4" when it's totally opened. I still had to hunt for a low profile AC unit to fit it, but it gave me a few more options.

I have a portable unit in my small ~20'x20' garage. The garage is very well insulated.
It's heated in the winter. It costs next to nothing to heat.

The portable AC unit is a 12000 BTU unit (I think). I wasn't expecting a lot out of it, but was hoping it would keep the temps in the low 80s. It barely does anything. It also has a water reservoir that needs to be emptied out constantly. That's a pain.

I'm not a fan. All it's good for is standing in front of when I'm completely covered in sweat.

If it was me, I'd maybe look at installing a large window unit through the wall?

 

[rlev11]

If you have to go portable, make sure it is a dual hose model. I highly doubt that any single hose portable would work as good as an 8000 btu window unit. I got a portable single hose, 10000 btu for my small one car garage (240 sqft), and it basically does nothing unless it is blowing directly on you.

I should have replace one of my slider windows with a regular window and got a cheap 5000 btu window unit. It would have worked better and probably been cheaper in the long run.

 

[blinn]

Mini split and don’t look back. Heat and air, efficient, quiet and reliable. No brained IMO.


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[bonneyman]

I have a 7,000 BTU Emerson unit in my little shop that makes things livable on all but the hottest days. Got it free (it was thoroughly used), but it needed a blower motor. $91 shipped.

It just quit last week after at least 6 years of service, compressor was not starting. Pulled it out, R&R'd the run cap and installed a little boost cap ($11). Cleaned it all out while it was out - works fine again. Can't beat those old R22 window shakers.

Have another one I got free as someone had dumped it outside the AC warehouse and the manager said, "I don't know anything about it - Get rid of it!"
Thorough cleaning, coils are a bit corroded but still works. I'm keeping it as a spare.

 

[ForceFed70]

Unless your shop is very well insulated, you're going to need more than 8k BTU for an 18x26x12 in Texas. I'd look for something closer to 12k BTU, more if poorly insulated.

Window units are more efficient but I understand your limited with regard to window opening size.

 

[fourspeed61]

Actually, that is what I was thinking about but just not sure how it would cool a shop like mine. Thanks for the input.

 

[fourspeed61]

Can you make the window open any taller. My bedroom widow has a similar problem. Mine has removable stops, so I can get an extra 3"-4" when it's totally opened. I still had to hunt for a low profile AC unit to fit it, but it gave me a few more options.

I have a portable unit in my small ~20'x20' garage. The garage is very well insulated.
It's heated in the winter. It costs next to nothing to heat.

The portable AC unit is a 12000 BTU unit (I think). I wasn't expecting a lot out of it, but was hoping it would keep the temps in the low 80s. It barely does anything. It also has a water reservoir that needs to be emptied out constantly. That's a pain.

I'm not a fan. All it's good for is standing in front of when I'm completely covered in sweat.

If it was me, I'd maybe look at installing a large window unit through the wall?

That is my biggest concern is how it would actually cool a shop that size. Also heard they were pretty noisy which I could tolerate as long as it cooled the shop.

 

[fourspeed61]

If you have to go portable, make sure it is a dual hose model. I highly doubt that any single hose portable would work as good as an 8000 btu window unit. I got a portable single hose, 10000 btu for my small one car garage (240 sqft), and it basically does nothing unless it is blowing directly on you.

I should have replace one of my slider windows with a regular window and got a cheap 5000 btu window unit. It would have worked better and probably been cheaper in the long run.

I agree, double hose is the way to go if I do the portable one.

 

[rtz]

Cut an opening in the wall and run any AC you want. Or a traditional unit and minimal or no ducting.

Or get another entry door and install the window unit into it. Then in the winter swap out the door with the one you have now.

 

[fourspeed61]

I have a 7,000 BTU Emerson unit in my little shop that makes things livable on all but the hottest days. Got it free (it was thoroughly used), but it needed a blower motor. $91 shipped.

It just quit last week after at least 6 years of service, compressor was not starting. Pulled it out, R&R'd the run cap and installed a little boost cap ($11). Cleaned it all out while it was out - works fine again. Can't beat those old R22 window shakers.

Have another one I got free as someone had dumped it outside the AC warehouse and the manager said, "I don't know anything about it - Get rid of it!"
Thorough cleaning, coils are a bit corroded but still works. I'm keeping it as a spare.

Yep, freebies are the best when on a tight budget. My brother in law has a window unit sitting in his garage not being use so maybe I should give it a try.

 

[fourspeed61]

Cut an opening in the wall and run any AC you want. Or a traditional unit and minimal or no ducting.

Or get another entry door and install the window unit into it. Then in the winter swap out the door with the one you have now.

Thought about that but these metal buildings are pretty thin so don't know it they would hold an 80lb a/c unit without beefing it up a bit.

 

[rtz]

You can bolt or weld up a support opening from angle iron.

 

[fourspeed61]

Unless your shop is very well insulated, you're going to need more than 8k BTU for an 18x26x12 in Texas. I'd look for something closer to 12k BTU, more if poorly insulated.

Window units are more efficient but I understand your limited with regard to window opening size.

Will go at least a 12,000 BTU or maybe 14,000.

 

[b-boy]

Thought about that but these metal buildings are pretty thin so don't know it they would hold an 80lb a/c unit without beefing it up a bit.

You'd need framing to hold the unit.

 

[dsimatt]

Take whatever money a portable unit would cost and put that towards a window unit or mini split. Portable are money converters, they turn your money into noise and barely cool anything as a side affect, any others option is better.

 

[WhiffySpark]

We have portables in 4 bedrooms with no issues. Yet you guys costsntly say they’re a waste of money.

I don’t think they’re the right choice to cool a garage.

 

[PoorOwner]

I have portable with 2 hoses.. 12k or so, it definitely blow very cold without creating negative pressure, the only issue is that it's pretty loud (the blower) plus the condenser all the noise an AC system makes is INSIDE the room.

 

[bonneyman]

Yep, freebies are the best when on a tight budget. My brother in law has a window unit sitting in his garage not being use so maybe I should give it a try.

Absolutely! But you don't always have the TIME to find a freebie when you need it. That's why I keep my eyes peeled and snag discarded stuff, rebuild it, and pack it away for a rainy day.
Window shakers are so flimsy these days they aren't worth repairing if anything but the most minor thing breaks. So people toss them and get another one. Could be just a thermostat or capacitor - if you know what you're doing those things aren't hard to fix.
Heck, you might visit your local Lowes or Home Depot and see if they have any freight damaged or warranty return window units available. You never know!

 

[themiller]

My 12k dual hose portable does about half the job my 10k window unit does.

When it’s 90 out with the portable AC I can keep the room at 76. When I use the window unit I can keep it at 71. Big difference. I use the portable in a much smaller room now and it’s fine.

 

[LS6 Tommy]

If you go portable, you'll need a good sized commercial machine. Anything less just isn't gonna cut it.

Tommy

 

[Falcon67]

Grandbury? Portable? Don't. Cut a hole in the wall sufficient to mount a 15~24K BTU unit.

 

[MrSurly]

How is your "metal building" constructed? Are there horizontal purlins? Metal or wood? Mine is a post frame (wood purlins). I used 2x6s to frame the opening and then another layer of 2-bys to stiffen it up. I'm in Longview, TX, my shop has three times the size, with foam and a 24K unit is enough (except for *right now* at 105 F.) I would suggest you get a 15~ 18K window unit and you'll have all the AC you'll ever need in that shop. I can't think of ANY reason to ever buy a portable....those are only for dire situations and difficult landlords. If you have a Homer bucket full of cash that you don't need, you could always buy a mini-split, but it sounds like you're a candidate for a mid-range window box.

 

[LS6 Tommy]

I'd throw some silicone or other sealant around that wall penetration.

Tommy

 

[MrSurly]

I'd throw some silicone or other sealant around that wall penetration.



Tommy

Not to worry, urethane caulked, sealed up and even foamed. That pic was during install


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[LS6 Tommy]

Not to worry, urethane caulked, sealed up and even foamed. That pic was during install


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I was thinking it didn't seem like the type of detail the guys around here would miss...

Tommy

 

[bonneyman]

How is your "metal building" constructed? Are there horizontal purlins? Metal or wood? Mine is a post frame (wood purlins). I used 2x6s to frame the opening and then another layer of 2-bys to stiffen it up. I'm in Longview, TX, my shop has three times the size, with foam and a 24K unit is enough (except for *right now* at 105 F.) I would suggest you get a 15~ 18K window unit and you'll have all the AC you'll ever need in that shop. I can't think of ANY reason to ever buy a portable....those are only for dire situations and difficult landlords. If you have a Homer bucket full of cash that you don't need, you could always buy a mini-split, but it sounds like you're a candidate for a mid-range window box.

So, is that the storage location for the ladder...or is it there just to plug in the unit?

 

[MrSurly]

So, is that the storage location for the ladder...or is it there just to plug in the unit?

Thank goodness for remotes, eh?

I seem to have an overload of ladders...


Whenever I meet someone who makes a big deal of "I do it all myself" but they sound like they might not be for real... I always say "Show me your ladders".

 

[Dragfluid]

If you have to go portable, make sure it is a dual hose model. I highly doubt that any single hose portable would work as good as an 8000 btu window unit. I got a portable single hose, 10000 btu for my small one car garage (240 sqft), and it basically does nothing unless it is blowing directly on you.

I should have replace one of my slider windows with a regular window and got a cheap 5000 btu window unit. It would have worked better and probably been cheaper in the long run.

They do make units to fit sliders. More spendy.

 

[Dragfluid]

The way that my place is insulated, all I need is a 5000 BTU window unit. Keeps the humidity down. 2386 sq ft.

 

[Mark in Baltimore]

We haven't used a window AC in many years, but we bought a Honeywell portable AC unit to cool our spray foamed attic. Works more than fine in the 720 sf space, and we keep it at a fairly high temp of 77 degrees, just enough to cut the heat when we need to go up there for a few minutes.

 

[theoldwizard1]

Hi all,
My metal building is 18w x 26d x 12h with 1 inch spray foam insulation on all walls and ceiling.

1" of spray foam on the ceiling in TEXAS !

You will never be able to AFFORD to run all the the A/C units required to cool it !

 

[MrSurly]

1" of spray foam on the ceiling in TEXAS !

You will never be able to AFFORD to run all the the A/C units required to cool it !

A valid point that I missed. I'll assume that it's closed cell, thats only R7. GFreat for the airsealing property, but not nearly enough 'R'.
I have open cell at 5-1/2 to 7" in the roof (about R20) and I wish there were more.

 

[Bigbandguy]

Add me to the growing list of those who were suckered by a "portable". I have a 200 SQ ft work shed, at present uninsulated and the portable won't make a dent. If I start it early in the morning it will sort of hold it down to bearable. Insulation is the next project followed by a hole cut for a window unit and a trip to the donation center for the portable.