diy solar

diy solar

Smallest Mini-Split?

Take a window shaker inside
you want cool use the cold side towards you, you want warm turn around the window shaker.
JoeHam, for what it sounds like your doing, this is the best/cheapest/easiest most common sense solution/suggestion made so far.
 
Hmmmmmm.

Maybe something like this:


Rated at 4000 BTU cooling.

Put the unit by me and the exhaust hose out the door when I want to cool.

Put the unit by the door and the exhaust hose by me for warmth. The noise might keep the coyotes from sticking their nose inside the door in the future ?.

Probably won’t make much heat on a freezing morning though since I probably can’t set the temp control low enough I’ll bet.

If I don’t find a better solution this might have to do. Add a little ceramic heater by my feet perhaps.
Portable units aren't efficient. 900W / 4K BTU is nuts.
 
will prowes has a window unit in one of his videos that works like a mini split ,it still able to use the window ,he said he paid about 400 bucks for it and i think he said its about 5k btu,s
 
will prowes has a window unit in one of his videos that works like a mini split ,it still able to use the window ,he said he paid about 400 bucks for it and i think he said its about 5k btu,s
It was a Midea u-shaped air conditioner. They come in 8, 10, and 12K BTU.
 
It won't be insulated, by choice, so there are no high hopes for great climate control. I'm happy to waste some solar power production just to take the edge off.
It puzzles me that you would not use the obvious solution, insulate. That takes care of cold mornings, and cuts out a huge amount of heat as well. Also with no radical temp swings, no moisture condenses.
I have a 53ft by 40ft seacan shop with a central 30ft wide bay. Before insulating, even at -30C, I could feel heat radiating into the interior on a clear sunny day.
I used 4x12ft x 3" thick high density foam panels from a walk in freezer, $50 bought me a truckload of them at auction. I used self tapping screws to fasten them to the inside of the seacan walls.
 
It puzzles me that you would not use the obvious solution, insulate.

I have mentioned multiple times that the door will always be partially open when I am present.

Why would I insulate in my particular use case where the door will always be open when I need to heat or cool?

I agree that might be appropriate for other applications but not mine.
 
I have mentioned multiple times that the door will always be partially open when I am present.

Why would I insulate in my particular use case where the door will always be open when I need to heat or cool?

I agree that might be appropriate for other applications but not mine.

Reminds me when I do yard work and come back into the garage for a break. Needless to say its pretty hot in there in the summer. While the door is open I just sit down right in-front of a 20 inch commercial floor fan that I bought a long time ago at Home Depot.

With a bottle of cold water I cool down quickly. That fan moves a lot of air.

I think that may do a better job than a 5k BTU mini split in an open container that is not insulated, and sitting in the AZ sun.




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Why not a evap (aka swamp) cooler? It won’t mind the open door and in AZ it will cool quite well as long as the dew point is under 45F.

A crazy Russian invented what he calls the M-Cycle heat exchanger and turned it into a product called the Coolerado. It is essentially a two-stage evaporative cooler where the conditioned air is cold and dry. Uses about 20% of the power of a conventional A/C system. He sold the patent rights to Delco/Aptiv (automobile systems) and it looks like Seely now owns the rights to the Coolerado product line:
https://www.seeleyinternational.com/us/commercial/brands/coolerado/ .
 
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Why not a evap (aka swamp) cooler? It won’t mind the open door and in AZ it will cool quite well as long as the dew point is under 45F

That’s my backup plan. I found one with a heater in it also:

 
That’s my backup plan. I found one with a heater in it also:

I’d skip the heater version and just buy the cheaper cool-only unit. An inverter sized to run the heater off of solar will cost a lot more than the price of this combo.
 
It's not in my tool kit but I watched a guy on YT make a split from a window rattler for a van build. It all made sense but there is draining extending and refilling the coolant lines. Heating is a different matter.
 
no insulation is really big problem, you are going to be absorbing a lot of heat.
If the panels are all on the roof of the container that will help quite a bit with the solar beat down hehe

lets see, 20' x 8ft across = 160sqft
so thats just over the 33BTU/sqft for cooling magic number for guestimates but close enough..that number, I think, is for insulated walls. I cannot imagine it keeping up with bare steel in arizona sun.

I think the easiest are something like the MRcool, and LG as high efficiency models.
Cheapest, not sure thats good direction to go with a split AC, real cheap would probably be around $1k, with double that for the nicer units.

Is there even a market for "used" mini-splits? I think once you break the seals and connect them, well, can you disconnect them without losing everything?
They can be recharged by an AC tech
 
That’s my backup plan. I found one with a heater in it also:



That thing has a 7 liter tank with an 8 hour timer. Evaporates roughly 1 liter in 1 hour. 1 liter of water equals 1 kilogram. 1 kilogram of water vaporized is 2,257 kJ of energy, and that's about 1780 BTU at 95 F. With an open door, that's basically a weak fan.
 
I’d skip the heater version and just buy the cheaper cool-only unit. An inverter sized to run the heater off of solar will cost a lot more than the price of this combo.

I’m already running an inverter big enough for it.
 

I have three of these running in Arizona. 1 in a shed that I converted to an office (over 1 year) and 1 in a workshop. 3rd 1in a container. Easy to install, very quiet. I'm buying a 4th one.
 
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