Opinions on Mini Split

[Imusprofit]

My pole building is 36' x 40', 12 foot ceilings with R19 in walls and R30 blown insulation with 6 mil vapor barrier for ceiling. Two 10' x 10' insulated doors and six double pane windows. I also have insulation under slab. I'm looking at this unit: https://www.ecomfort.com/LG-LA240HYV1/p67941.html

My building is pretty much 1 large open space, so I'm thinking a single zone unit should work. Part time usage with 65 degrees winter and 78 degrees summer when I'm in there. I live in New Jersey so temperatures are moderate for the most part. Do you think a high efficient 2-Ton unit will suffice?

 

[ace10]

IMO, one head is not going to move the air around 1500 ft2.

I have a slightly larger space with higher R values. If I turn the 72" ceiling fan off, my two 1.5 ton units seem to work on about 2/3rds of the space. The big fan evens everything out.

 

[SALIV8]

Mini splits are a compromise for either space, or money. There isn't any other reason anyone has put forth that makes them anything else.
It's fine to compromise. We'll put one in the spousal units sewing room this coming spring. We do it as a compromise to the 12x20 superinsulated room it's going in that is on the hot in the summer side of the house.

Buy a conventional system and be happier.

I disagree.

I don't want ductwork running through my space, collecting dust and junk.

Additionally the rebates available and the energy savings from the zone control is amazing.

Pair that with very classy decorative and functional looking idu's and amazing temp and humidity control specifically where you want it, and when you want it.

The space savings is also a serious plus as most everything is outside as opposed to large a coils, filter racks, plenums, etc.

There is no indoor drain line needed like with a conventional.

There is no return/supply sizing and spacing needed.

I could go on.

A traditional central ac/heat unit actually would have cost me less based on the quotes I got. Labor included.

 

[justinjoyal]

Mini splits are a compromise for either space, or money. There isn't any other reason anyone has put forth that makes them anything else.
It's fine to compromise. We'll put one in the spousal units sewing room this coming spring. We do it as a compromise to the 12x20 superinsulated room it's going in that is on the hot in the summer side of the house.

Buy a conventional system and be happier.

It depends on the area to be cooled/heated.

Mini-splits are much more efficient, and I don’t see what’s wrong with saving space and money..

OP: 2 x 12kbtu heads is what I would advise. Single 2T if you can deal with slightly uneven temps. This is considering you dont need fast recovery.

 

[Imusprofit]

It depends on the area to be cooled/heated.

Mini-splits are much more efficient, and I don’t see what’s wrong with saving space and money..

OP: 2 x 12kbtu heads is what I would advise. Single 2T if you can deal with slightly uneven temps. This is considering you dont need fast recovery.

Thanks for all the input. Fast recovery is not necessary. I have 3 ceiling fans installed to help circulate the air which should help even out the temps.

 

[Imusprofit]

How many outlet vents will a single minisplit in a 36x40 have?

Just one big air vent/distributor. The model I'm looking at has a 4 vane, power swing vent.

 

[yeldogt]

Think you need to do a proper load calculation -- that way you can understand what it's going to need to maintain a temp. Remember -- the normal calculators are only going to tell you the maintenance number. Trying to bring temps up and down is another matter and will get you oversized equipment when and if you do want to maintain a given temp.

Having a comfortable space with a single point heat or cool location is totally dependent on the insulation and air tightness of the building. having a leaking door and wanting to work next to it is not the same as being over by the heat source and away from any window or other cold spot.

I have a single wall unit (propane) -- and it's fine in my 1700sf space. But it's extremely tight.

 

[Browneye]

For a living space I would install a 2-head 3-ton unit. For a garage a single 2 or 3 ton with the unit located where you spend the most time, or a 2-head unit on each end.

That's 1440 sq feet which is a pretty good area for one head, but you might move some air around with a box or ceiling fan. I would be leaning toward a 3 ton unit for the hot days. JMHO.

Normally for tall ceilings the temp stratifies anyway, which is what you want instead of blowing it around.

Certainly seems do-able to me. I love these things!

 

[rattle_snake]

Yes, IMO. I have a very similar building and based on my experience one 2T mini will do just fine. Put it were you spend most of your time.

I went with a pair of 1.5T (I'm in AZ). Just one can cool the whole building given same insulation/doors.

Yes a multi-head or multiple separate units will have better temperature distribution. Do you want/need consistent temperature everywhere?

2 separate units provide redundancy should something go wrong and was cheaper in my case (Daikin) than a dual head.

There are many opinions to these type of questions. If you read enough of these types of threads (help me size/type my space) you will see who consistently provides useful help based on real experience. That said I'm not an HVAC guy, just a incompetent hack who went through this recently with basically the same building.

 

[Imusprofit]

Much thanks to all contributors. My building layout/usage is about 60-70 percent collector car and parts storage, with the other 30-40 percent being used for my work bench and lift. I was planning to mount the single head above the work bench, which is about 10 feet away from the lift. Also an overhead fan in the same area. I'm sure a 2-head system would be better, but I was hoping to get away with a single head unit.

 

[SALIV8]

I think a single head unit will be perfect for that setup.