Looking to install a mini-split heat pump (A/C). Advice?

There was a thread about mini-splits back in '15 but it looks like there have been some advancements so I wanted to start anew.

I have a vacation home which is heated with propane and cooled with a window a/c. The window a/c is 15000 BTU’s and is OK but I would like just a bit more. Propane pricing, in a handful of dealers is almost as money grubbing as the oil heat industry pricing.

I am considering getting a minisplit heatpump at around 18000 BTU’s and install it myself. I already have the power from an old central a/c in it’s outside location and am pretty darn handy and have worked on car a/c’s and repaired a mini-fridge unit by replacing the compressor, so I have the knowledge and tools for working on a/c’s.

My idea is to use the mini-split as the when temperatures are not too cold and heat with the propane furnace as the backup and also primary heat when the temp’s get too cold for efficient operation of the heat pump.

I am looking at something like this: https://www.amazon.com/Pioneer-Diamante-Ductless-Mini-Split-Conditioner/dp/B08K3NSJWM/?_encoding=UTF8&pd_rd_w=nclhg&content-id=amzn1.sym.03bef33a-a357-4fe3-9505-7fd4d6236957&pf_rd_p=03bef33a-a357-4fe3-9505-7fd4d6236957&pf_rd_r=N4ND1YVQ2PJVY2JYSKC4&pd_rd_wg=4I2sg&pd_rd_r=42f034d5-c361-42e1-b4f9-aa35292b30b6&ref_=pd_gw_ci_mcx_mr_hp_d&th=1#customerReviews.

And am asking for advice pro/con this concept. Thanks


We also had this thread back in June:

I posted my experience there (and got some good advice). Happy to answer any other questions.

Most manufacturers require you to have the units installed by licensed professionals. Otherwise they won’t honor the warranty. I know one company, Mr. Cool, that specializes in DIY installations. You probably need an outdoor shutoff on the electric supply.

I’ve got one of these. 12000 BTU and runs on 120 volt AC (it was their smallest unit at the time I purchased). I don’t have the tools, experience or access to Freon so this DIY solution worked well for me.

The lines are pre-charged and installation was pretty easy.
The only problem with these is that there are only 2 line sets lengths available. If you don’t plan the location carefully, you’ll have a lot of extra line next to the compressor. It doesn’t affect the operation, but it is unsightly.

I’ve had no problem with mine since I installed it about 3 years ago.

Found an old email. They are 16 feet and 25 feet.

If everything comes together I’ll be getting a Mr. Cool compressor and 2 heads installed by a professional soon. I have mounting physical problems or I’d do it myself. He’s a Mr Cool dealer though, and he will cut lines to specific lengths so there’s no extra to hide. I’m not getting it because of the brand since I won’t be installing it myself. I’m going to this guy because he seems to be doing a good job at installations.

I wonder if providing options for seasonal shading or sunning might be useful?
If the outside split is placed to the south, in direct sun, in the winter, maybe even with added reflection, it could be more efficient for heating. But then having a large area shade sheet/wall that can be placed to protect it in the summer can aid in cooling.
Solar radiation on the unit will enhance or detract the efficiency depending on intent.

I installed my own Celiera in 2005 and it works great. I think Home Depot or Lowes sells them now. You need a vacuum pump and gauge set to evacuate the lines.

We had a Mitsubishi system professionally installed a little more than a year ago, and we’re very happy with it. If I had been 20-30 years younger, I might have considered a DIY system, but not at 66.

Our system came with remotes for each room unit, with control via an app being a $1,000+ option. We chose the option and are very glad we did. The remotes are quite cumbersome and difficult to use (the LCD panel is not back-lit!), and we never use them.

My understanding is that while it does help, it’s only single-digit percentages at best. It’s really all about the temperature of the air flowing through the coils and not how much sun or shade there is.

I’m totally onboard for heat pump systems with a more conventional backup heat source, even keeping the old system that’s being “replaced.” There are fixed costs to that, such as for natural gas piping and other infrastructure. With propane it’s the upfront cost of the tank, and possible replacement cost later. The trick is getting the right thermostat that can dynamically switch over from one heat source to another. That’s challenging enough for central systems but mini-splits are even more bespoke. There are ones that can use wired thermostats rather than the typical infrared remote, but they’re usually proprietary. That’s where I’d focus my research for something like this.