Heating and cooling - mini split

My parents had good luck with a Mitsubishi single zone system in an apartment they had over the detached garage.  When unoccupied, it had a dehumidification setting so you could let the temp do what ever but keep the humidity (and unwanted growth) under control.  They lived in this apartment full time for two years before starting then finishing the main house.  The unit was first commissioned in 2010 and had zero problems until they sold in 6/22.

I suspect that you may find that most of the pro installers will only have Mitsubishi, at least in my experience.  After you get over the sticker shock, another option is to install most of it yourself (you and your husband can easily handle it) and only bring in an HVAC tech for the final evacuation and testing, though you can do that yourself too.   Doing the installation at least yourself can easily save 50% or more compared to complete professional installation.   

A friend of mine installed a Pioneer mini split and has had good experience.  Checkout their prices compared to the quote you get.  He installed all of the lines himself, which requires you to get HVAC rated copper lines and make the flared connections yourself, and called an HVAC tech to evacuate and pressure test the lines.  Most minisplits I have seen come precharged so as long as you get the lines evacuated and leak free, you simply open a couple of valves to complete the installation.  

I installed a MrCool DIY unit myself because it comes with precharged or evacuated lines and requires no pipe work and no HVAC tech. IIRC, it costs about twice what a comparable Pioneer unit does.  I would guess that, not counting the electrical that I did beforehand, it took me about 8 hours over several days to do the installation by myself, though I was pacing myself because it was hotter'n hell that week.  My wife did help for about 5 minutes to help steady the other end of the indoor unit while I hoisted it up on the wall and fed the lines through the hole in the wall with my other hand.   Other than that, the hardest part for me was cutting a 4" hole through the brick facade on my my house, though now I figured out the trick it would not be that hard the second time.  

Things to consider:  The areas you plan to condition is probably going to require at least an 18k BTU unit and 24k might be better.  That will probably require a 240v dedicated circuit so you may also have to include electrical in the cost analysis.  HVAC guy may include that in their quote.  An alternative might be to install two separate units that run on separate 120v circuits .  For the smaller space, a 9k unit may be enough with a 12k unit for the larger space.  9K may be enough for the larger space too, though it could be marginal on the hottest and coldest days.  

Also note that you can get ceiling mounted units too.  This frees up wall space and allows you to put it in the center of the room for more uniform coverage.  

Thanks for the personal experiences - very helpful. We don't have a written quote yet, but the brands mentioned to my husband weren't ones I had heard before. I don't think we have the needed "install expertise" but maybe we can assist. 

We are also hoping to add a minisplit in the room we are shifting out workout equipment into in our house. That room is only about 14x19 with tall ceilings. Mainly looking for added cooling as it is climate controlled.

I’ve had Mitsubishis and LGs. They’re both fine. Our LGs have been slightly more fiddly than the Mitsus, but they also have a electrostatic filter function which is great when California catches on fire and pollutes our air.

If you’re going to have a head-unit in / near your shop, you’ll need to keep the dust out of it. Mini-split filters are entirely unsuited to sawdust. That can be as simple as a box built over the split to keep the dust out of the coils.

Thanks Dave. I had asked about the dust and he said it shouldn't be a problem if I kept the filters cleaned. I remember discussions on here about add-on filters so know that's important.

https://craftisian.com/topics/991-mini-splits-and-dust

Thanks for that link!

I've been meaning to look in to this, too. I suppose that, with fall around the corner, and winter quickly following, I should get on with it. My main concern is keeping the space manageably warm in the winter, as the spring/summer/fall isn't much of an issue.  

You'd be surprised just how easy they are to install, especially if you buy ready to attach lines.  They are designed to be installed in places that do not have HVAC companies to perform the installation.  If you can drill holes, connect a few wires and work a wrench, you can handle it.   I also just noticed that Pioneer is now selling kits with ready made lines so you may not even need to learn how to solder and flare the copper lines, which is really the only thing you can mess up, IMO.  You can even buy the vacuum pump and manifold gauges for the final evacuation and testing at Harbor Freight -- probably for less than the HVAC tech service call.    Pioneer and MrCool have installation manuals online.  You can read through them and there are videos on YT that go step by step through the installation including showing how to evacuate and test that the lines are airtight. 

Steps as I remember them using ready made lines:
- Identify where you want the outside and inside units.  Hanging the inside units on an outside wall will simplify the installation.  If you choose an inside wall, you may have to run condensation drain lines either to a sink or to an outside wall and you may need longer control wires and copper lines.  To simplify and minimize cost, find a location where you can easily run electrical service outside.   
- Get your electrical connection to the location outside the wall.  If you are not familiar or comfortable with electrical requirements, hire an electrician.
- Make a pad or buy a wall hanging kit for the compressor unit.  The wall kit is recommended if you live somewhere that gets deep snow to maximize heating.  I used large concrete pavers so I didn't even need to make forms or mix concrete. 
- Drill holes for lines.  For outside walls,  a ~4" hole where the inside unit will be installed is best.  The units come with a template to help with hole location.  Unless you have stone or brick, a hole saw works great.
- Mount the compressor on the pad or wall kit.
- Mount the hanging plate to the inside wall.  This is basically a French cleat. 
- Mount the inside unit on the cleat while feeding the short attached lines, wires and drain through the 4" hole.  This is the only part where two sets of hands was needed for me.  
- Attach the lines between the short lines and the compressor.
- Connect control wires between the inside and outside unit.
- Connect the power lines. 
- Evacuate and test (not necessary with the MrCool DIY)
- Open the valves on the inside and outside unit to fully charge the system
- Pretty it up and protect the lines by installing line set covers.  
- Turn it on.  
- You just saved a couple thousand dollars at least so go buy more tools.  

Lazyman - I appreciate your confidence, but reading the list makes me sure that I'll need a professional to do this! The one unit will be for a pole barn so not sure hiw the attachment will need to go. 

Still waiting on the quote for details on the unit, etc.

Watch some videos.  MrCool has some good ones that gave me the confidence to do it myself.