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Cooling A Shed Studio with a 2000 BTU Server AC Unit

johnhornor

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Aug 27, 2020
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I am a newbie to solar but I'm building a studio in my back yard and I've been trying to rig it on the cheap. The problem is, I live in the American south, where it's regularly above 90º F during any month without an R and often in months with them and easily 60% humidity. A studio without some kind of AC unit would be pretty unusable. However, simply powering a 500w window AC unit with solar would entail more money than I want to put into this studio. Because I would keep some items in the studio I wouldn't want to regularly be over 100º and I want to be able to work there in the daytime occasionally, I gotta figure out this problem and don't have any real experience to draw from. So I made my way here. I've been binging Will's incredibly informative videos, bought his book (and a couple of other DIY solar books) and now I'm in the planning phase and I have to figure out if this is even feasible.

My shed will be 96 square feet, around 1100 cubic, as well insulated as possible, so I thought I might be able to make do with a smaller AC fixture than a 500w, 5000BTU window unit. In searching for smaller BTU units, I found a 2000BTU server ac. It only draws 276w. The load will entail my laptop, a few DC lights, a fan, a Bluetooth speaker in the studio.

So, I was thinking about 400 - 600w of solar panels (luckily my shed area gets around 8 hours of direct sunlight), a one or two of the cheaper $600 lithium iron phosphate 100wh batteries, and a 2000/4000w inverter. It's this even feasible?

Anyway, I'd love any sort of feedback or suggestions. As I said, I'm an absolute newb.

Thanks for your time and consideration, in advance.
 
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Will you be working standing or sitting?
Would be best if you could work lying down.
Face down is even better.
An air conditioner attempts to fill the space from the bottom up with cool air.
So if you sit cross legged on the floor to work you may only have to fill the cold air pool to ~36 inches.
If you stand up, then you need to fill the pool to ~72 inches.
That is 2x the cubic feet.
Optimally you would pull air from near the floor, remove the heat and pump it back in, at or slightly above the desired height.
Proper placement of the temperature sensor will help too.
 
Buy a mini-split and run an extension cord from the house. It's the only way you'll make it work without major investment. 2000BTU/h will only make you furious that it's not more.

Now that I think about it, if you could suspend a duct fed helmet that you could don and move about the studio, that might do the trick. The duct would be fed by the A/C unit and direct it to your head, which is an important part of the body's heat exchange system. Alternatively, fashion a backpack, wear the A/C unit and duct the exhaust outside.

Unfortunately, there is no solution that will permit you to cool the entire volume acceptably.
 
Was all that necessary? If I've breached some sort of forum protocol, my apologies. Don't sprain your arm patting yourself on the back for your cleverness.
Have you watched the Will Prowse Youtube video's on his solar shed which is little bigger than yours.

There is a thread on here too.
 
Have you watched the Will Prowse Youtube video's on his solar shed which is little bigger than yours.

There is a thread on here too.

I have. Good video, but either he didn't mention or I missed how large his solar array is and his battery bank.

Thank you for the response.
 
Those server AC's, how much they go for and how cold can they go? Do they use digital controls or mechanical thermostat?
Might be a good choice for a walk in cooler. A mechanical unit would be cheaper to swap out the thermostat.
In this case it would be for a well insulated cellar or basement with a low heat load.
 
Those server AC's, how much they go for and how cold can they go? Do they use digital controls or mechanical thermostat?
Might be a good choice for a walk in cooler. A mechanical unit would be cheaper to swap out the thermostat.
In this case it would be for a well insulated cellar or basement with a low heat load.
I've been thinking about one as a battery cooler in Phoenix. I don't worry about charging below freezing, just the batteries getting too hot.
 
If I'm understanding the Server AC unit correctly, it's the same as a Portable Air Conditioner. (As opposed to a split system.)

That means that all the internals are in the room that you're trying to cool. That means that they generate a bunch of heat in the room that you're trying to cool.

Recently, whatever department of the US Govt who "protects" us in consumer affairs changed the BTU ratings for these things. essentially lowering their effectiveness by a third.

So, for example, the 12,000 BTU portable AC that I bough last year (before I knew about this inefficiency) now has a stated BTU capacity of only 7500.
 
If I'm understanding the Server AC unit correctly, it's the same as a Portable Air Conditioner. (As opposed to a split system.)

That means that all the internals are in the room that you're trying to cool. That means that they generate a bunch of heat in the room that you're trying to cool.

Recently, whatever department of the US Govt who "protects" us in consumer affairs changed the BTU ratings for these things. essentially lowering their effectiveness by a third.

So, for example, the 12,000 BTU portable AC that I bough last year (before I knew about this inefficiency) now has a stated BTU capacity of only 7500.

Yes, I already have a perfectly good 10,000 BTU portable. Judging by two weeks running it from a generator in Florida, it has about the same cooling capability as a 6 or 7,000 BTU normal window unit. You can certainly feel the heat radiate off the plastic hose going out the window, but it does a really good job of removing humidity and making a bedroom in south Florida livable after a hurricane. It doesn't work as well here in Arizona, but that's comparing 92 and humid to 112 with no humidity.

I've also been looking at 12v coolers to set up a "less than 100 degrees" battery box. They are pretty cheap, and run directly off of DC.
 
The 12 VDC coolers are (probably) using the Peltier Effect, and are terribly inefficient. (That is, make a lot of heat.)

As for the portable AC - I keep my hose to window very short (a foot) and I wrap Reflectix around the hose. Makes a big difference.
 
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Oh, those little mini-AC's that I've seen on Amazon? I've wondered if they really work (well).
 
What is your budget? I can run a small window AC or mini split for about six hours after the sun goes down (so figure (9AM-12PM right now) pretty much as long as the sun is shinning. I have a little under $3k invested. Any chance of running a 15amp extension cord from the house? :)
 
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