Mini-split AC units?

Longrifle

Old Mossy Horns
Contributor
What I'm working with is two 45'x8 hi-cube shipping containers sandwiched side-by-side for a total area of ~ 720 sqft of floor space. I feel like it's pretty well insulated, with R34 in both ceilings and walls. Recently I created a 16'x16' common area in the center of the two by removing 16' of the walls between the two containers. I also added walls and doors to create two separate 14'6" areas on either end of the second container to later be used as laundry room and bathroom. Right now a small Rinnai propane heater handles one container and the common area up nicely but whew, the propane costs are ridiculous!

Anyway, I found a new Senville 24,000 btu mini-split unit on Ebay for less than a grand. I have it sitting here, waiting to be installed. I'm hoping the larger btu unit won't break a sweat to both heat and cool this area.

With their increased popularity I'm wondering if anyone has gone to this type of unit and if so, how it compared cost and performance-wise to a conventional heat and a/c unit...
Opinions?
 

nchunter

Twelve Pointer
I would think that while running it would use the same amount of electricity as a same size ducted unit.
Should run slightly less because of no heat loss through the ductwork.

I looked into them awhile back for a shop I built.
I choose a ptac unit because it was faster and easier for me to do myself.

In your situation I would have gone with the mini split. Quieter and only have to have a small hole for the line set.


Sent from my iPhone using Tapatalk
 

duckmauler

Eight Pointer
Unfortunately I can’t give you specific #s. We don’t run it all the time, but when we have ran it, I’ve never seen an increase in my bill thst I correlated it to.
 

MJ74

Old Mossy Horns
Just curious...how did you get to R34 in the walls?

Sent from my LG-US996 using Tapatalk
 

timber

Twelve Pointer
Know several that use one simular. Not sure if same brand. But they do good job. . Think they are fairly cheap to run. Biggest draw back have seen they are a little noisy depending on where you have them mounted.
 

Longrifle

Old Mossy Horns
Contributor
Just curious...how did you get to R34 in the walls?

Sent from my LG-US996 using Tapatalk
A company out of Houston sells a product called Prodex. It's only about 1/4" thick and comes in a 150' rolls and each layer is rated R17. It's both a thermal barrier and a moisture barrier and I added two layers on both walls and ceilings. The only drawback is that it lacks sound-proofing characteristics so I'm also framing inside with 2x4 and adding standard R13. I'm trying to build a cooler out of these containers to make the place as energy efficient as possible...
 
Make sure you read the installation manual on the lengths of the lineset. Some require a 15ft minimum and if you don't follow that, it can lead to compressor failures in a short amount of time. Also, keep the recommended clearances on the evaporator. I have put in a bunch of mini-splits and the biggest downfall would be they aren't as convenient as a residential split system to get parts for.
 

CoonHntr

Four Pointer
I recently installed three 9k btu units and a 12k btu unit in our vacation home on the coast. We are down Friday through Sunday pretty much every weekend and our bill averages 100 a month. That’s with running a couple of the units while we are gone during the week. I have no complaints whatsoever with the mini splits. I love the fact that each room can be set to its own temp.
 

Longrifle

Old Mossy Horns
Contributor
Eastover519, thanks but I wouldn't attempt to install them myself. Lotta things I can do but that ain't one I'd tackle. Lucky to have a professional HVAC nephew in the family!

Coonhntr I'm spending almost twice that in propane just to heat this place right now...
 

sky hawk

Old Mossy Horns
Contributor
I'm pretty sure, just like a traditional unit, the monthly cost will depend a lot on how hard it is being run and the space you are using it for. I think you won't know the answer until you install it. But I'd be willing to bet that it's cheaper than your current setup. We put one in the garage a few years ago, and it works very well, but is used lightly. I have no idea how much it costs us.
 

Scrub

Twelve Pointer
Contributor
I just put a MrCool DIY unit in a 16x20 room off my building. Took me about 2 hours to install it and it works great. Really simple to install and uses very little energy, its a 17.5 Seer Rated unit. Came with a 7year Compressor and 5 year parts warranty and they make them up to 36,000 BTU....https://mrcooldiy.com/
 

Longrifle

Old Mossy Horns
Contributor
Scrub I've got 720 sqft to heat and cool and the unit I bought is 17 Seer rated as well. I was hoping that with two layers of R17 backed up by one layer of R13 the place should be pretty easy to heat and cool. But IF I see that the single 24,000 btu unit is working too hard and I need to get another smaller unit to take care of one of the smaller rooms I'm good with that....
 

Scrub

Twelve Pointer
Contributor
Scrub I've got 720 sqft to heat and cool and the unit I bought is 17 Seer rated as well. I was hoping that with two layers of R17 backed up by one layer of R13 the place should be pretty easy to heat and cool. But IF I see that the single 24,000 btu unit is working too hard and I need to get another smaller unit to take care of one of the smaller rooms I'm good with that....

That 24kbtu should be fine especially as insulated as you have it.
 

shurshot

Ten Pointer
I have had a Fujitsu unit in my hunting camp for 8-9 years now with zero problems. Can’t remember what the BTU rating is but it handles my 3 bedroom 900 sf place very well with the unit mounted in the middle of the house. Would even be better if I had complete wall and floor insulation. I would highly recommend these types of units over anything else. Quiet and very efficient.
 
Top