Choosing the right brand for a mini-split

[sportbikerider78]

Time to get AC!

What brand do you guys suggest and why? This will be a 3 head unit with one compressor and about 42000-48000BTU...which is about 3.5 ton.

It will be a DIY for me..so any thoughts you have would be great.

Thanks guys.

Here are a couple I have been looking at but have no data for one over the other.

https://www.ecomfort.com/Mitsubishi-M3H42W12151800-B/p57088.html


Looks like LG is about $1k more over Mitsubishi.
https://www.ecomfort.com/LG-L3L42W09151800/p78886.html

 

[Tegbert]

I’m only seeing a 50 dollar difference between those two that you linked. The lg has a higher seer rating though but one smaller headway 9k versus the Mitsubishi at 12k. Don’t forget the line sets either if you didn’t know that they don’t come with them. And the flaring tools and vacuum pump and such to evacuate the lines.

I’ve only known people with Mitsubishi and daikin units I haven’t met anyone with an lg but that doesn’t mean much just what the installers use around here.

Also if you diy a lot of manufacturers will not warranty the units if something happens.

Other than that i have nothing useful to add. I’m in the same boat right now trying to size a mini split for our home.


Lopi Rockport
Blaze King Ashford 25

 

[sportbikerider78]

Ok..thanks for the info. What I was going to do is do most of the install but have a refrigeration guy come out, test the lines and get the unit running. I was going to do all of the mechanical connections and hang the units. Really not that much to it, other than lots of grunt work with 3 head units going up to 50' from heat pump.

These units certainly vary greatly in price! Significantly cheaper. They seem to get good reviews...at least on this site.
https://www.alpinehomeair.com/viewp...w5yoGpdSORq-Lj0ExMXC4YoQriRNZZX4aAq7rEALw_wcB

 

[maple1]

I don't have one but hope to some day.

From the reading & researching & talking I've done - it would be a Mitsubishi, Daikin, or Fujitsu. Those seem to be the big 3 in performance & quality, and don't think there's much difference in performance or price.

 

[CaptSpiff]

.... I was going to do all of the mechanical connections and hang the units. Really not that much to it, other than lots of grunt work with 3 head units going up to 50' from heat pump.

Others here with lots of experience. Mine is limited, but I recall reading that the units are all pre-charged and line length is super critical. I think 50' puts you near that limit. Not sure if the multi head unit has specific total line length.

 

[sportbikerider78]

Yup..I'll look into all the details before I do the install. I have seen many units go up a wall, around a corner, into a house, and then to bedrooms on the second floor. Way over 50'.
We will see.

Regaring "hyper heat" for the mitsubishi's...at what temperature does it make sense to have this? Meaning, how low will the heat pump crank out heat in the cold without paying another ~$1,000 for this feature?

 

[Brian26]

I know these things cost a fortune to have a company install but your are essentially going to get zero warranty. Mitsubishi gives you a full 12 year warranty only when installed from one of their licensed dealers. You diy and its not charged right and it blows in a year they are going cover nothing. Thats a big gamble with a 6k Mistubshi minisplit. My neighbor had I believe that exact Mitsubishi unit you listed installed. I think he said he paid around 10 or 12k to have it installed. Twice the price but he doesn't have to worry about it for 12 years.

I think you will also find if you call most reputable local hvac companies nobody will want to touch the refrigeration side on something you installed. You are mostly likely left to finding and hvac guy to do it on the side like on the weekend or something. Any if something goes wrong hes going to want nothing to do with it.

I can see attempting a DIY on cheap $1000 minisplit and if it last a year or two and blows its not a big loss. In no way would I spend 6k on a Mitsubishi and attempt to diy with no warranty. Notice on that website you linked there is nothing listed about the warranty.

 

[sportbikerider78]

I'm willing to take that gamble. Hell, even if it blew up right away and I had to order another compressor unit I'd still make out ahead on an installation cost over 5k.

This isn't voodoo rocket science. We are talking about leak testing. Pulling a vacuum, then charging the unit. Companies charge a fortune, but that company is just made up of a bunch of medium paid guys that usually, like some extra cash jobs on the side.

I'm looking forward to learning to flare a copper tube, getting the right tools and then having someone come take care of the rest of it. Not worried at all.

I just research the heck out of projects to hedge my bets. I've always worked

 

[fbelec]

just make sure you follow the directions with the unit. to a tee. i can't remember what brand it was but on of the brands used a different size line set. if you can see if you can find out when the company you choose has a class. just get a certificate on the unit and i think you are ok. classes are i think just one day. if i can nail the hvac guy i work with to use one brand i can get my cert. even tho i'm a electrician. he's up in the air because all are compressors are made in china.

 

[peakbagger]

The techs I talked to several years ago claimed that at best I might get heat down to 40 degrees without it. I have never looked the details, but the hyper heat option has several pieces but the big one seems to be a variable speed compressor.

FYI, the multihead Mitsubishis used to have a bad rep with the same techs. They claimed that unlike the single head units, the multiheads required far more servicing. This was early on when the hyper heat multi head were just coming out, so it have been growing pains.

 

[fbelec]

a mini split heat pump is different from the standard ducted heat pump temp wise the last ducted heat pump i wired was a york affinity. it would work down to 32 to 36 degrees. it was field set then at that point it would switch to the 97 or 98% eff. nat gas burner that was modulating. the standard mini split heat pump will heat down to 0 degrees and then there are sum that go down to -15. i wired a few reg heat mini's i can remember one i did over a garage that when i tried it out when wired it was throwing really good heat at a 17 degree outdoor temp

 

[maple1]

Regaring "hyper heat" for the mitsubishi's...at what temperature does it make sense to have this? Meaning, how low will the heat pump crank out heat in the cold without paying another ~$1,000 for this feature?

I'm not sure about the exact answer there - but to me it would be missed opportunity to not go with it even if it is $1000 more. In climates anywhere near moderate, I don't think there is a more efficient way to heat. Even if it won't do 100% of your heat.

 

[vinny11950]

Time to get AC!

What brand do you guys suggest and why? This will be a 3 head unit with one compressor and about 42000-48000BTU...which is about 3.5 ton.

It will be a DIY for me..so any thoughts you have would be great.

Thanks guys.

Here are a couple I have been looking at but have no data for one over the other.

https://www.ecomfort.com/Mitsubishi-M3H42W12151800-B/p57088.html


Looks like LG is about $1k more over Mitsubishi.
https://www.ecomfort.com/LG-L3L42W09151800/p78886.html

Good thread. I too have been thinking of getting another heating system in the house to back up the pellet stove and the electric baseboard heaters which are never used.

I have been trying to figure out how much electricity the unit would use to estimate cost per month. I found this video online

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Of course Long Island electricity charges are double everywhere else in NY state, but it may still be worth it.

If you read the comments below the video, viewers explain the ghost load issue of the unit as the heater for the unit itself (important process).

I wonder if a heat pump would be considered a main source of heating.

 

[peakbagger]

I run my Mitsubishi Hyper Heat all winter whenever the outdoor temps are over 20 F. It will put out heat down to -12 F but far less of it and COP drops to the point where I am better off using a space heater. I have surplus PV generation that is net metered so its normally "free" to run although I must admit that cold stretch in late January into February chewed up my surplus. I may actually have an electric bill this month after 5 years of not having one. Once it gets over 30 F at night the boiler definitely gets shut down. The thing to realize with a mini split for heating is set it and forget it, dont let the house get cold and then expect it going to heat it right back up quickly. It takes a long time for it to catch up as its 12000 btus an hour compared to a 100,000 BTU oil boiler and a 100,000 BTU wood boiler.

 

[sportbikerider78]

I'm going to use this unit primarily for cooling. I have a wood stove and a new oil boiler system. Not too worried about heat. A $1000 buys a lot of oil!

I spoke to a Mitsubishi distributor and we will be working the details out.

 

[begreen]

Spoke with a local dealer last weekend at an Earth Day event about the state of art in these systems. He is sold on Mitsubishi for developing solutions for the American market. They have a new 5 ton unit that produces 60K btus at 17ºF.

 

[maple1]

I'm going to use this unit primarily for cooling. I have a wood stove and a new oil boiler system. Not too worried about heat. A $1000 buys a lot of oil!

I spoke to a Mitsubishi distributor and we will be working the details out.

True but that $1000 up front cost can also displace a lot of oil with lower cost heat over its lifetime. I think with our house that much oil would only be maybe 2 months of heat at best.

 

[sportbikerider78]

I do a 5 year ROI on home purchases. If they don't pay back in 5 years, they aren't worth it to me. I don't know if I will be living here in 10 years.

I would use it in shoulder season because that is when a heat pump is most effective. I can still do that without the HyperHeat feature. To me there is no payback with a great woodstove and new furnace.

 

[begreen]

Part of the ROI can come into play on resale too if the investment is one that has value for the future buyer.

 

[sportbikerider78]

Thanks for the help and advice guys. I am going with the ~2.5T/30,000BTU unit with 3 heads from Mitsubishi.

 

[Soundchasm]

Good luck on the endeavor. We installed a 1-ton Mitsubishi mini-split in a well-insulated sun room. A general contractor installed it during a remodel. It's pretty neat. It got its own dedicated 220V line and breaker.

It did need service for a leak. My mind has blanked out the painful parts, but a few connections were redone. We stop using the room when it gets to 30-40 degrees. Even though the walls, windows and ceiling are excellent, my big, giant alien brain didn't notice that the "floor" is the roof of the poured concrete garage! IR gun reads the floor at 40 degrees in the winter.

Make sure you run it for 15-20 minutes once a month in the winter as maintenance.

I thought the max line set was about two stories. Shorter is better.

The last caution is that the refrigerants work at stupid high pressures. Even a tiny, tiny little crack in a copper flare joint and you're doomed. Whoever does that has to be an expert. And the line ought to be surgically clean inside.

All those cautions aside, it's still kind of neat to watch the thing work. And I don't really see it on my electric bill, which I watch like a hawk.

We went through a MAJOR replacement of the 3-ton for the house. All the research I did indicated that you're not picking equipment - you're picking the installer!! So I found a wonderfully OCD guy with decades of experience and so far so good.

Last thought, but you've probably already gone there. Would three separate units be possible? If anything happened you wouldn't have all your eggs in one basket.

 

[begreen]

Have you considered laying down some insulation under flooring in the cold room? It can make a huge difference. My small shop is on slab and I couldn't heat it very well with an electric heater. The heater would run continuously and it still always felt cold even after hours of running. I put down some foam interlocking flooring in there and the difference is amazing. Now I can easily warm up the place in an hour now. There are more elegant solutions for a nice finished room, but they make this stuff in colors instead of the industrial grey that I used in the shop if you want an inexpensive solution.

 

[sportbikerider78]

Thanks for the input. I don't think these units are different pressures than other home AC heat pumps, are they?

No way I can do 3 units. That would involve more breakers. 3 outdoor line sets. 3 disconnects. 3 heat pumps. That would take my heat pump costs from $2700 to over $4000 and greatly increase installation costs.

 

[begreen]

I have a couple friends that have multi-head mini-splits. They have been fine. The only issue has been with one that had a control circuit board burn out due to a power surge. This was a Fujitsu system. The other has a Mitsubishi system and it's been trouble free. Both were installed about 5 years ago. Locally due to our rural power, the installer now recommends adding surge protection for the hp circuit to protect the electronics.

 

[Soundchasm]

Thanks for the input. I don't think these units are different pressures than other home AC heat pumps, are they?

No way I can do 3 units. That would involve more breakers. 3 outdoor line sets. 3 disconnects. 3 heat pumps. That would take my heat pump costs from $2700 to over $4000 and greatly increase installation costs.

I can't quote anything chapter and verse because I've slept since then, but methinks that ye old Freon was a very low pressure and connections weren't critical. The newer refrigerants are much higher pressures and a last ditch kind of repair like soldering a connection has to be upgraded to brazing, or something like that.

I hope I'm not spreading misinformation, but my overall impression is that the connections are critical and the lines need to be clean.

Our 1-ton unit was under a grand for the air handler, line set and compressor. I think that was everything. But you are right about breakers and disconnects. Just to flog the idea and give options, you could stagger installations of individual units every six months or so.

But best to stick to what you've researched and just solve the problem.