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.  

Barb, watch some Mr cool videos. It’s really, really simple. Honestly, you have plenty of talent to handle it. They’re pretty much plug and play. As noted, the electrical is probably the only thing you need to source, and that’s only because most people aren’t comfortable with 240v work, but it’s not hard. Just watch the videos and see what you think….its a great way to save money…with which you can buy a larger, more efficient unit…or more tools!

Barb, Ryan is absolutely right.  We've seen how you tackle projects and you have all the of the skills you need, especially if you go the MrCool DIY route.   I would classify everything listed on the steps list above as only basic skills required.  Only area you may need help with is lifting the inside units up to hang them on the bracket.  I predict that once you get an estimate you will find that you will literally save thousands.  

I actually did my own electrical work too, including adding a new subpanel to enable more outlets in my shop.  I had a retired electrician friend show me the ropes and that is really not difficult either.  Frankly, 120V vs. 240V are really not that different from each other.   Scariest part was working inside the main box without turning the power off but even that turned out to be less scary than I thought it would be after my friend showed me the tricks of the trade.   But I understand any hesitance to tackle that yourself.   To save money, you could run the conduit, wire and install the boxes and just have the electrician inspect, correct and connect your work to the panel.  That would save you hundreds at least.  And if there is already a subpanel out there, you can completely turn off the power at the main panel and work safely to add the breakers you need.  

BTW, you said this is pole barn.  Is there insulation?  Is it mostly air tight?  If not, I would concentrate on getting it sealed and insulated.  Even without a minisplit, that alone will improve your comfort out there and save cooling and heating costs after you add the minisplit.  

I'm smiling at how much confidence you have in my ability to handle this. I however do not feel so sure! I've watched several videos and maybe could do it, but then what if I run into issues? What is the joke - cost estimate by a pro to do a project is x-amount...if you as the client watch it is 50% more...and if the pro has to fix a DIY  attempt it's double (or in today's world likely more than that).🙄

And the pole barn is really right. Fully insulated with concrete floors. Side room has insulation above the ceiling (painted chip board walls and ceiling).

There is also a couple areas with some prior water damage that we will be trying to repair. Potential mold (not tested) so that should be fun. 

The MrCool DIY really is pretty fool proof.  Except maybe for drilling holes in the outside concrete base and maybe the electrical connections. We've seen you do all of the other skills required.   Hopefully the estimate won't be as high as I fear.  

I don't have the written quote to see details yet (guessing the Labor Day holiday might have delayed this). 

Question on usage. Any thoughts on only turning on as needed? The one for our rec room would only really be required when working out (planning to move the weightlifting equipment, treadmill, bike, etc inside the house). Not sure of the workshop area. Right now I keep all finishes and glue inside the house to avoid the heat in summer and potential freezing in winter.

I only turn my shop minisplit on when I am planning to head out to my only partially insulated shop.  Even on the hottest days, it only take about 15 minutes to get it comfortable enough to work and since it blows right at my workbench, I rarely wait that long to get started.  In fact, more often than not, I turn it on when I go out and just turn on a fan (in the summer) to take the edge off until the MS gets the shop down to temperature.   It is slightly different in the Winter when I am heating the shop but I just wear a sweatshirt or something until the shop is to a comfortable temperature.  It takes a little longer it seems in the winter but it also usually has further to go to get it up to temperature.  One thing to watch out for in the winter is managing condensation.  Concrete slabs and cast iron tools wills sometimes show a little condensation between between heated and unheated times.  If you find that you have a wet slab or condensation forming, you may decide you want to set the heat in the shop to the lowest setting.  This will make warming it up during the coldest days quicker too.  

Lazyman - thanks for sharing your approach. That is my thought, but the guy that came out for the quote said it's harder on the system to ask for big temp changes. Maybe like you noted for the condensation issue, setting to a less than optimal as a baseline might be a consideration, and then to the more ideal temp when in the area.

I leave my minisplit in heat mode at the lowest setting (62F) all winter. Avoiding any condensation on cold metal is nice, also not worrying about having anything freeze, and being able to walk out to the shop and just start working is great. I don’t turn the split up while I’m out there, just leave it at 62. The shop gets up to about 75F on nice sunny days in the winter because my shop windows catch the winter sun, and the split will only kick in a couple times overnight.

The unheated, adjacent wood and motorcycle storage area stays above the freezing temp of Pepsi all winter that way, too. 

My sweetie says it costs us about $40 or $50/ month for the coldest month or two. I think the shop heating season here is four months total, maybe five.