Mini-split AC brand and vendor recommendation wanted

[John Stankus]

Since San Antonio is a little bit warm in the summer, I am thinking of installing a mini-split AC for the garage. I am thinking a 24,000 BTU single split system. Any suggestions on a brand and a vendor to purchase it from? I plan on doing a self-install.

Regards


John

[Sherzod Niazov]

I've got LG 30k BTU mini-split, bought online, love it. Easy to install. Don't forget to get a bigger unit if you have heavy-heat generating machines like a cyclone.

[Jim Andrew]

I looked online for a new furnace and AC for the house, wanted to purchase new and use the old ac on the shop. Found a company online that sells the units shipped with free freight, and then talked to my local guy, and the local guy beat them about 150$. Of course, I also talked to the lady at the company that installed my old units, and it would have been significantly more. But the estimator didn't bother to come and give me a price.
Now I have central air in my shop. Worked on the duct all afternoon and this evening for a while, and still don't have it together.

[Chris Damm]

I've got a Daikin And works great. I was told by several installer friends that Daikin was the best and they sell other brands!

[Scott T Smith]

Mitsubishi "Mr. Slim" models have a great reputation. We used to use them in cellular sites where they ran 24/7.

[David Hawxhurst]

i like the mitsubishi mr. slim. but i imagine that any of the reputable manufactures would be good. you did list anything about the garage so its hard to say if the 24k btu is enough.

[John Stankus]

I guess I didn't give all the details of the garage. It is a three car garage with no insulation in either the walls or ceiling. One wall backs to cooled space in the house. I found a simplified manual J calculation (was for a whole house application). Total area 690 sq ft 8ft 4 inch ceiling ht 88 ft of perimeter wall.

Depending on the insulation assumption and cooling design temperature I got the following values from the calculation.

No insulation
90 F 14.7 kBTU/hr 95 F 17.5 kBTU/hr 100F 20.2 kBTU/hr 105F 23.0 kBTU/hr

R7 in walls and R11 in attic (walls have peg board that previous owner put in that should be easy to take off and insulate behind)
90 F 5.1 kBTU/hr 95 F 6.0 kBTU/hr 100F 7.0 kBTU/hr 105F 8.4 kBTU/hr

A little bit of insulation appears to make a big difference.

Calculations did not take into account heat load from water heater that lives in a closet off the garage or running tools (but I am heading more the neander direction any way)

I do plan on insulating when I can, but the garage will have plenty of air leaks. I would like a unit that I can set to dehumidify to keep the moisture down.
There does seem to be a wide range of prices on the units.

Those of you who have bought on line how was your experience with the vendors and would you suggest them?

Thanks

John

[Alan Lightstone]

Buy from a reputable name brand. I have a no-name unit (likely Chinese), and fortunately it has stayed working. My friend bought two identical units, and when they had problems, they were unfixable.

I would personally go with a Mitsubishi or LG.

You'll love having a split AC unit. Makes all the difference in the world.

[Sam Dotson]

I just had a 18k / btu Mitsubishi Mr. Slim installed in my insulated 400 sq/ft garage and I couldn’t be happier.


Sam

[Mark Welte]

We have a Mitsubishi Mr Slim that cools our server room and has been in continuous use for over 6 years now. Only thing it does not like are power outages and cottonwood trees. Those are the only two issues we have had as we lost a couple fuses due to power problems and the condenser plugged up with cotton. For the price it has been a great unit.

Mark

[Will Rowland]

I would buy Mitsubishi or Fujitsu. I don't think there is any appreciable difference - in performance, construction or cost - between the main brands, but I learned the hard way (with a Sanyo unit) that most HVAC companies only install these two brands, as at least around here, those are the only two brands sold by the supply houses. From what I can tell, Mitsubishi and Fujitsu have put more effort into selling their brand to HVAC companies.

As a result, if you need a repair, especially under warranty, you're way better off with a Mitsubishi or Fujitsu than a Sanyo/Panasonic, LG, Friedrich, etc. In my experience, most HVAC types are always looking for an excuse to justify higher costs, and subpar service - and an "unfamiliar" brand is a great excuse...

[John Loftis]

I just did a bunch of research on mini-splits and the advice above is consistent with what I found. Pretty much everybody loves Mitsubishi (Mr. Slim) and Fujitsu. I couldn't afford those brands, since they run around $2k+. I know you get what you pay for, but I couldn't stand sweating through another Texas summer without getting something in the shop. So I ended up getting a 1 ton Amvent unit off Amazon for $800 with lineset included, no shipping, no tax. My shop is smaller than yours and mine is insulated, so I think you'll need a 1.5 or 2 ton. My HVAC guy is going to install it today or tomorrow... I'll let you know.

[John Stankus]

I'm leaning towards one of the LG systems right now. The one I like LS246HV seems to show up as discontinued from some of the vendors. I am still keeping an eye out for the Mr. Slim and Fujitsu units but they seem a little more expensive and less available.

Who are the good online retailers for these systems? There seems to be a bit of a range of vendors. If you purchased online, could you give me an idea of your experience with the vendor?

John L. -- How did the install go? Good to hear from an NTWA member (I was on the board until I moved to San Antonio in 2006)

Thanks for the help

John

[Adrian Anguiano]

Does the MR Slim, etc mini split systems, do they require a gas line? Or do they run off just electricity? My Neighboor hood only has Electric available.

[Scott T Smith]

Does the MR Slim, etc mini split systems, do they require a gas line? Or do they run off just electricity? My Neighboor hood only has Electric available.


Adrian, the one that I had was 240VAC only; as I recall it only required a 20A circuit too.

[Adrian Anguiano]

Anyone have any documentation on how to install one of these systems? I want to see how possible it would be to self install, and what all is involved, and a good step by step instruction guide.

[Scott T Smith]

Anyone have any documentation on how to install one of these systems? I want to see how possible it would be to self install, and what all is involved, and a good step by step instruction guide.

I self-installed my system. If you are familiar with basic electrical installation, and working with copper tubing and compression fittings, you can install your own. Typically they come pre-charged; you need to set the outside unit, and run power (typically 14/3 romex) and the tubing kit in-between the two. Tighten up the fittings, complete the wiring, open up the valves and you're done.

The shorter the length from the evaporator to the condenser, the better you will be. If you have a long run, it would be best to have an HVAC tech pull a vacuum on the lines.

[Justin Jump]

@ John Loftis.....

I too am curious how the AmVent product showed up, installed, etc......I looked at these, but I noticed that Amazon listed these as being distributed by Ramsond Corporation. Just as an FYI, I Googled Ramsond, and got hits on a lot of complaints about Ramsond, damaged units, bad compressors, etc. I hope this doesnt hit yours, but if you could post some details, that would be great.

[Ben Martin]

I purchased a 2.5 ton Fedders unit for my 780SF shop, going to start the installation this weekend.

Scott, you sure about just opening the valves? From what I have read, you need a professional to vacuum the air out of the lines before the system is activated.

[Scott T Smith]

I purchased a 2.5 ton Fedders unit for my 780SF shop, going to start the installation this weekend.

Scott, you sure about just opening the valves? From what I have read, you need a professional to vacuum the air out of the lines before the system is activated.

Ben, normally you would pull a vacuum on the lines if they are a longer run (>25'). However, when I installed mine I asked this same question to my HVAC guy, and he told me that on the small systems if the run was short no vacuum was needed (although it is always a good idea). The added benefit is that the line kits for the mini-splits is fairly small diameter, so there is not much contamination. As I recally, my line run was only about 8', so the vacuum was not required.

[Joe Leigh]

Not so.

A vacuum is ALWAYS required. The minute the copper lines are opened to the atmosphere in order to make connections to the indoor and outdoor units, the moisture presently in the ambient air is immediately present in the copper lines. Only a proper evacuation can remove this moisture. in fact a correct manufacturers supplied line set comes with access ports install for the purpose of connecting a vacuum pump for proper evacuation.

Also you need to follow the manufacturers recommendations for maximum length of copper tubing allowed. In addition, additional refrigerant is required based on the total length of the line set. This charge is CRITICAL ina R410-a system.

Contrary to the few who got lucky with their homeowner installation, HVAC installation is not a DIY project.

[Scott T Smith]

Not so.

A vacuum is ALWAYS required. The minute the copper lines are opened to the atmosphere in order to make connections to the indoor and outdoor units, the moisture presently in the ambient air is immediately present in the copper lines. Only a proper evacuation can remove this moisture. in fact a correct manufacturers supplied line set comes with access ports install for the purpose of connecting a vacuum pump for proper evacuation.

Also you need to follow the manufacturers recommendations for maximum length of copper tubing allowed. In addition, additional refrigerant is required based on the total length of the line set. This charge is CRITICAL ina R410-a system.

Contrary to the few who got lucky with their homeowner installation, HVAC installation is not a DIY project.

Joe, on the mini-splits the access ports are usually included on the condenser unit. The line sets typically are comprised of copper lines inside of insulation - nothing more. Some of them even have the line-set precharged with quick-connect fittings, so the system is never open and exposed to moisture.

Considering the quality of many of today's HVAC techs, there is no doubt in my mind that many of the members of SMC are fully capable to install their own mini-split system. I concur that a larger split system is beyond most DIY'ers (even SMC'ers), but many of the mini-splits are designed for DIY installation.

[Aaron Berk]

I just installed a KWSG012 (12k BTU) Klimaire Mini split in my under 400 sq ft uninsulated garage.

I paid $50 off CraigsList and then $200 to have it recharged
I think I came out ahead.

My shop is so much more tolerable. I went 7 yrs with no AC.... man it's nice to have ac.

[Joe Jensen]

I have a Sanyo mini-split for my AZ 3 car garage. I was limited to 20 amps 220V without spending a ton to run a new line 120 ft underground so I bought the highest efficiency unit I could find that was close to 20 amps. The unit is very efficient but it takes several hours to cool down all the thermal mass in the garage. Also, I put in R17 insulated doors and the ceiling is insulated. The two side walls are not and I need to do more there as the AC has a hard time keeping up when running the big dust collector and tools. I suggest going bigger than you think. I think I'd be happier with a true 3 ton.