Ductless AC - Mr. Slim

[VoteQuimby]

looking at a home with boiler heat and a ductless AC system. They have two Mitsubishi Mr. Slim units in the home that are approximately 15 years old. I'm having a hard time researching the longevity of these systems. Does anyone here have these types of units? Good - bad? Thanks!

 

[NutBucket]

They're hugely popular in Asia and Europe. There's no reason it won't have a long life with proper maintenance.

 

[dphantom]

We put in 2 Mitsubishi 2 years ago. Boiler heat here as well and no way in a log home to retrofit duct work. They are quiet and very efficient.

 

[Mandres]

I'm a fan of ductless mini-split systems, but 15 years is really pushing the expected life of any AC compressor imo. Down here in Texas they usually last 8-9 years. I'd budget for replacements sooner rather than later.

 

[DrPizza]

I'm a fan of ductless mini-split systems, but 15 years is really pushing the expected life of any AC compressor imo. Down here in Texas they usually last 8-9 years. I'd budget for replacements sooner rather than later.

Of course, in Texas, you're running them 9 months of the year. An AC compressor might only run 2 months of the year in some of the more northern states.

 

[VoteQuimby]

I appreciate the responses. We're in Northern Michigan, so we're looking at occasional use 3 months out of the year. We turned the units on and were surprised at how quiet they were.

 

[NutBucket]

Yeah, the silence is a huge selling point.

 

[Kaido]

I have several friends who have put them in. The new H2i ones do pretty well now in the winter too (they typically do poorly extracting heat in really cold weather & need an additional heating system on cold nights). They can get expensive if you do your whole house, but they are pretty sweet because there's no central point of failure (unless you do a multi-unit only), quiet, does heating & cooling, has a remote control, etc.

My only wish is that they'd get better integration for home automation. Also, make sure you have a secure mount on the compressor piece outside, especially if you can do a small concrete pad or something. One of my buddy's has a low drone all the time that is really annoying because he didn't mount it correctly.

 

[Red Squirrel]

I've toyed with the idea of these mini splits. They're not all that expensive compared to big window or portable units while being more efficient. I think they are DIY too which is nice.

But I figure for maybe double the cost I can just get central AC installed and do the entire house, so that's probably what I'll eventually end up doing. The nice thing with central AC is there is a full blown air movement throughout the whole house so it's better to get rid of humidity, at least I would imagine so. And of course the benefit of cooling the whole house. I find even with my 1 ton portable unit, I can get my home office down to like 20C when it's 25 in the rest of the house, but as soon as I turn it off it starts to climb fast because all the other rooms are hot so it quickly brings the room back up in temp.

On the other hand for the little that I need AC it's hard to justify paying a couple grand for central AC. Every summer I toy with the idea of finally getting it done, then suddenly it's fall again.

 

[Kaido]

I've toyed with the idea of these mini splits. They're not all that expensive compared to big window or portable units while being more efficient. I think they are DIY too which is nice.

But I figure for maybe double the cost I can just get central AC installed and do the entire house, so that's probably what I'll eventually end up doing. The nice thing with central AC is there is a full blown air movement throughout the whole house so it's better to get rid of humidity, at least I would imagine so. And of course the benefit of cooling the whole house. I find even with my 1 ton portable unit, I can get my home office down to like 20C when it's 25 in the rest of the house, but as soon as I turn it off it starts to climb fast because all the other rooms are hot so it quickly brings the room back up in temp.

On the other hand for the little that I need AC it's hard to justify paying a couple grand for central AC. Every summer I toy with the idea of finally getting it done, then suddenly it's fall again.

The problem, at least in my area, is that a 1:1 H2i unit (indoor/outdoor) is about $2k installed. So if you want say five of them for your house (let's say 3 bedrooms, main room, and kitchen), you're looking at ten grand easily. Versus getting a $1.5k central A/C box & having ductwork run, or even better, putting in a Spacepak hi-velocity system.

In my ideal world, I'd have a Mr. Slim in every room, but they don't make them small enough for just a regular bathroom, and their central control stuff still stinks. They really need to add some home automation features, because per-room temperature control is an awesome idea, and they need to make different sizes for different rooms, including smaller rooms. The current wall-mount units are way too big for the size rooms I have, and for your common American bedroom size. And some of the neater configurations are only available in places like Canada for some reason!

I've had some furnace & A/C glitches over the past month. It would be nice to have a distributed system so that even if one failed, the others would still work, so you could at least move to another part of the house. My A/C was non-functionality for a few days, my ceilings are too low for ceiling fans, and the rooms with all the stuff in them don't really leave room for floor fans, so it got pretty toasty for awhile there. I ended up installing a Honeywell Wifi thermostat, which is pretty nice because the color touchscreen is really intuitive, and the wireless control from my smartphone is nice, but it'd be even cooler to be able to control it per-room...I don't want to heat up or cool down the whole house, just my bedroom in particular, but without having to burn through money using an electric heater or whatever. We're almost there, we just need a few more models - c'mon, Mitsubishi!!

 

[IronWing]

We priced out ductless A/C-heatpump and ended up going with a traditional central air/furnace unit. We already had the ductwork so there was little price difference between the two configurations put together by various contractors. Adding inside units to the bathrooms would have pushed the ductless option well above the cost of traditional HVAC and not adding them would have left the bathroom unvented.

 

[natto fire]

Sorry to piggyback your thread OP, but I have a few questions about this brand specifically.

I think Mitsubishi was the first ones to bring these units here, and I think they were the de facto mini-split systems for a long time?

I notice there are lots of different brands of them now, from obvious junk brands to respected names like Carrier. I am recommending to my sister go with one of these units for her addition over the garage.

Initially we were talking about radiant heating in the floors, and expanding her central air system to service the addition.

Does anyone have any experience with the other brands of these systems, or is it just a better idea to go with Mitsubishi still?