Mustering the information and courage to install a mini split system

[zuren]

I need to install heating and cooling in my new man-cave shed. It is 16'x10' with a flat dormer. There are a decent number of windows and the ceiling is vaulted with a peak height of 9.5'. This is going to be my office, clean project area, escape from the family, etc. I'm currently wiring and installing insulation.

I'm researching mini split systems. I need a single zone, 9000 BTU, both heating and cooling. I've been told to consider systems with "hyper heat" since my location can get into the negative digits in the winter.

I just got a quote for $3200 installed for the smallest Bryant system; don't know if it is "hyper heat". We have another ballpark quote of $4500 for a Mitsubishi with hyper heat.

I looked online at the "DIY" systems. Pretty much all of them in the 9000BTU category are names I've never heard of, so that spooks me in regard to parts and support. I also read that the DIY kit install is not as clean since you are not cutting lines to fit your exact install. I'm decently handy, and have been told that installing a mini-split is not that difficult; you just need a vacuum pump and a couple other special tools. This is the non-DIY system I'm looking at:

9,000 BTU 30.5 SEER Wall Mounted Mitsubishi Mini-Split H2i Hyper Heat Single Zone Heat Pump - MZ-FS09NAH

Designed with enhanced efficiency and supreme comfort, the Mitsubishi MSZ-FS09NA / MUZ-FS09NAH single-zone mini-split is an ideal wall mounted unit to heat and cool a single room of your home or office. With its enhanced sensors and automatic intelligent controls, the MSZ-FS09NA / MUZ-FS09NAH is...

hvacdirect.com

By the time you add the necessary install kit, you are at $2000. I know how use tools and follow instructions. I will look into renting a vacuum pump and what tools are needed. Is it a pretty straight forward project or are there compelling reasons to leave it to a pro?

Thanks!

 

[Skiff Builder]

I did a three zone install at our house 5 years ago. I have no real interest or experience in installing or using AC . That said, it was straightforward to install it all. Flaring, evac, nitro pressure test and letting charge in worked ok. Still working. Unit the wife got from one of her distributors- She's happy, all that counts.

Side story- had to borrow a Johnson Controls uniform from work in order to buy some things at Universal Supply- would not sell to a civilian. There is always a way.

You'll be fine.

 

[Git]

It's been several years but I ordered a dual zone Mr Slim from eComfort and did the majority of the install myself including the flares. For warranty purposes I had a local Mitsu dealer come out and 'start up' the unit - check everything over, nitrogen test, vacuum, etc etc. I spent about $140 on tools - flaring tool, new tubing cutter, nylog, etc. and paid $300 for the start up. I could have bought all the tools necessay to do it myself, but I figured it was pretty much a wash buying them versus hiring someone to do it, so you may want to call a local place and see what they would charge you for a startup service

 

[glennm]

I installed mine myself and found a guy that vacuumed it down and tested with nitrogen. Cost me $150. The pump and gauges were over $300 and I don’t have nitrogen. I called a lot of people to find someone that would do it. He also had a micron gauge

 

[59ctd]

I am also looking into a mini split AC system for my workshop/garage. The portable unit I've had for ~7 years now is making really loud noise and so I think it is done. I need a 12k to 14k BTU unit and a minisplit will take a bit to install but worth it in the long run. Biggest question is to go with a 110v or 220v unit. with a 110v unit I could use existing circuit in the shop but a 220v unit would need a new wire put in which I could do but not fun in an insulated attic. Workshop has a 2x30A110v so 220v remote breaker box so both 110 and 220 are options. Not sure if 220v route is worth the effort to run the wire in the attic.

 

[Phuckin' Jim]

Hi.
If the 110 volt unit was on its own circuit, (it should have been) , you might be able to use the same wiring to run a 220 volt unit.
You tube user "electronicsNmore" has a good video explaining how to convert a 120 to 240 volt circuit on his channel if you want to search it out.
Hope this helps.

 

[Phuckin' Jim]

 

[59ctd]

The 110v circuit has a GFCI and one or two outlets and also supplies power to my radiant floor pump and tankless water heater so it is not dedicated to an AC system. The current AC is a portable unit with the vent that goes out a window and it just plugs into the wall outlet. I'll probably end up running a 220v line over there when I do put in the mini split system.

 

[like2wheel]

I have a similar situation, but where I would want to put a mini split I do have a 240 circuit for my lift.
Considering the infrequent & short needs of the lift, I'm wondering if there is a correct way to supply both from the one circuit.

 

[jjrbus]

Mini splits are not rocket science to install, they do require proper installation, the right tools. Most mini split failures are due to improper installation! They usually do not fail immediately but will take a couple weeks or a year or so.

The Mr cool DIY can be purchased with a 15 foot lineset and installed in a serpentine fashion to avoid the coiled up linset behind the unit.

 

[madmaxnj]

I installed a Mr Cool DIY on Garage Mahal. The DIY kit requires no 'special' tools. You should have flare wrenches for installing the pre-vacuumed lineset, but I just used regular open end wrenches. I coiled the extra lineset outside going to the compressor so there are no low spots for the lubricant to pool up. A vertical coil so the lineset is always going down, probably about 16" diameter coil. The low BTU units run off 110V.