Anyone With Experience With Multi Zone Mini Split Systems?

[telstar]

Greetings all! I am seeking advice regarding a couple of different mini split 3 zone heat pump/ac systems that I'm looking at having installed in my 100 year-old home. I've been looking at several different posts, but have yet to uncover much info based on experience, rather than informed speculation. My basic home stats are as follows:

My home is located in Memphis, TN. It has 2 stories plus a semi-finished attic room. The exterior walls are uninsulated (and probably won't be anytime soon), balloon 2x4 frame, with plaster walls and approx 4-5-inch thick limestone facing on the exterior of the first floor, slate tiles on the 2nd floor (which doesn't get nearly as cold as the 1st floor in winter!). The attic is insulated, and I have r-30 insulation under the ground floor (crawlspace, which incidentally has a plastic sheeting for a vapor barrier over the dirt).

The rooms I'm looking at for the 3 zones (what we can afford to have put in right now) are downstairs -room 1 is 15' x 15' with an 11' ceiling (225 sq ft, 2 exterior facing walls), room 2 is 14' x 14' x 11' (196 sq ft, 2 exterior facing walls), room 3 is 18' x 12' x11', 216 sq ft, with one (8' x11') exterior (south facing) wall. All of the windows are single pane, wood set in masonry, 3' x 6'. The total square footage of the downstairs area is 989.

We have 2 gas logs at present, which aren't really doing the job, probably partially because we have such high ceilings and standard-height (80” -ish) openings between rooms. And in spite of MLGW's laughably fictitious claims to the contrary, using natural gas here is insanely expensive, so we'd reaaally like to get off the stuff if possible. The two outdoor units we've been looking at are the LG and Mitsubishi multi-zone units (36000 BTU) with a matched combination of (2) 18K BTU indoor units and (1) 12k BTU unit. (see manufacturer pages below)

http://www.lg.com/ca_en/air-conditioners/commercial/LG-LMU365HV.jsp

http://catalog.mitsubishipro.com/item/mr-slim-m-series-heat-pumps-2/mxz-series-heat-pumps/mxz-4b36na

Is there anyone out there who has experience with this type of system in a multi-zone application and can give me an idea if this would be a decent heat setup for my type of house and climate? The HVAC guy I'm planning on hiring highly recommends mini splits and has installed several single zone systems, but he hasn't installed a multi-zone system before. Also, any advice regarding the heating performance of ceiling cassette units vs wall mount units?

I'm pretty set on having a mini split system put in, as having a central unit put in isn't really an option, nor is it something I'm really interested in due to the mess that having the ductwork installed would make of the walls, floors, and/or ceiling. I'd love to hear from someone who has installed one or more of these multi zone units in a similar scenario(s) and can give me an idea of how well they work for heat...Thank you in advance for any information that y'all can provide, and please hit me up if I can provide any additional information about my home...

[captain123]

They work great, you'll love them.

[bill88]

Go on the Mitsubishi site and find a local diamond dealer, we install the multi-zone systems all the time they work great.

As far as the sizing goes, any good contractor will be able to size it correctlly for you.

FYI - you can't put two 18,000 btu and a 12,000 btu on a MXZ-4B36 would need to go to a MXZ-8B48

Good luck

[Airmechanical]

been looking at several different posts, but have yet to uncover much info based on experience, rather than informed speculation.

i have worked on plenty of them

i would never, ever, ever, put a minisplit in my house, or recommend anyone i know to do so

and this is all due to the service work i have done on these multihead systems



.

[nvr2old]

One customer has both a Mitsubishi and an LG, 3/1 zone system. He removed ducted system that served 2 story home. Mitsu on second floor, LG first. Units installed about 1 year apart with the Mitsu installed first. He would have prefered Mitsu for both floors but Mitsu did not have residential ceiling cassette. He says both heating and cooling bills have dropped significantly and temperature thru out home is even. He also says indoor Mitsu units are much quiter than LG. All units are installed on interior walls or in ceiling between first and second floor. Expect to do alot of cutting and patching if installed on interior walls

[captain123]

Talk to some of their customers, they will be glad to tell you what kind of work they do.

[telstar]

i have worked on plenty of them

i would never, ever, ever, put a minisplit in my house, or recommend anyone i know to do so

and this is all due to the service work i have done on these multihead systems



.

What kind of problems have you seen? With Mitsubishi or LG units? I've seen that there are a lot of no-name brands out there that look pretty questionable, but I've generally heard nothing but good reports on the Mitsubishis and very little good or bad (though generally good reports) on the LG. The installer I'm talking to has said that his outfit installs quite a few of the mitsus with good results. Thanks for your help!

[Airmechanical]

What kind of problems have you seen? With Mitsubishi or LG units? I've seen that there are a lot of no-name brands out there that look pretty questionable, but I've generally heard nothing but good reports on the Mitsubishis and very little good or bad (though generally good reports) on the LG. The installer I'm talking to has said that his outfit installs quite a few of the mitsus with good results. Thanks for your help!

big problems with the LG's within a year or 2 of service

sensors, compressors, circuitbords, exv's and stuff like that

i just would not want one in my house

i have heard some good things about the mitsu

but still would never put a minisplit in my house

.

[telstar]

big problems with the LG's within a year or 2 of service

sensors, compressors, circuitbords, exv's and stuff like that

i just would not want one in my house

i have heard some good things about the mitsu

but still would never put a minisplit in my house

.
Good to know -thanks for the info Airmechanical!

[chuckcrj]

The co. I work for has installed minisplits for 10+ years now (Mitsubishi and Fujitsu) and we have found them more reliable than any central air units. Except for about ten Turbo Air units, those are worthless.

The main problems have been mice, snakes, etc getting in and chewing wires and crawling on the boards, not manufacturer defects.

Just in the process of changing out the first failed compressor out of the hundreds I service.

Most of these units are heat pumps and run year around.

If/when I build a house it will likely have a Mitsubishi City Multi unit plus infloor heat, due to good experiences with them.

[96gsxr750]

He would have prefered Mitsu for both floors but Mitsu did not have residential ceiling cassette.


Mitsubishi is going to come out with a 2x2 cassette for Mr. Slim with in 6 months or so i think.