Mini-Split Selection- What would You Do
My Mitsubishi hyper heat 18k wall mount single head heat pump has [apparently] been leaking for a few years. I finally found a tech that was willing to diagnose the leak (air handler coil) and I am advised that replacing the whole system is the only practical option given current parts availability.
The path of least resistance would be to install another Mitsubishi hyper heat 18k. That is what the contractor I am currently working with has offered. I am hesitant to do this, mainly because my experience with my current Mitsubishi hyper heat unit has been less than ideal:
1. I only got ~7 years out of it before it began leaking.
2. My experience with the local Mitsubishi diamond contractors has been mixed. They mainly seem interested in installing new systems. Ability/willingness to diagnose & repair is limited.
3. Flaky behavior that could not be resolved by contractor (excessive air handler noise, short cycling/oscillations, wide deviations from setpoint).
In terms of what the unit needs to do, cold weather performance is important. The current hyper heat unit has shut down twice (in ten years) on exceptionally cold nights. During the coldest part of the season, my current 18k unit is probably running close to or at full modulation a meaningful percentage of the time. My electricity is expensive so COP at near full modulation matters. Not using it much for AC.
Some specific questions:
Am I likely to have a better experience with another manufacturer vs. my experience with Mitsubushi ? Any specific recommendations for 18k wall mount, single head systems with cold weather performance comparable to or better than Mitsubishi hyper heat ? If I am going to be replacing this thing every 7-10 years should I be looking at Gree/Midea or other lower cost options ?
Should I buy an R410a unit now while they are still available or should I wait till the next generation refrigerant systems appear in the supply chain ?
Would appreciate your thoughts on any or all of these questions…
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
You can buy just the air handler: https://hvacdirect.com/mitsubishi-18-000-btu-ductless-3d-i-see-air-handler-mszfh18na2.html
In stock, ready to ship.
But usually leaks occur at fittings, the fix for the leak is to tighten the fitting.
Who owns your HVAC company? There has been a nationwide trend recently of private equity firms buying up local HVAC companies. Not to paint with too broad of a brush, but when private equity gets involved with something it's not good for anyone involved except for the investors in the private equity company.
What I have heard specifically about HVAC companies is in order to increase sales, the techs will be given a blanket rule that all systems older than a certain age need to be replaced. That age is often seven years.
HVAC companies that are owned by private equity won't advertise the fact, on their website they'll talk about the plucky family man who founded the company 50 years ago. But on the private equity website they do like to advertise their acquisitions. Some googling and you'll find the information there.
Hi DCcontrarian,
I think the air handler you linked to is the current model. I have been told by Mitsubishi that the current model air handler will not work with my compressor (I think I need an MSZ-FE18NA). If you know a workaround that would allow me to use the MSZ-FS18NA with an older compressor, that would be interesting info.
Don't know about the contractor ownership situation locally. Private equity could certainly be part of the problem. It seems to me that manufacturers are part of the problem as well. Mitsubishi does not seem very interested in long term support. The whole eccosystem seems to have decided that these products should be treated as disposable consumer items rather than long term infrastructure.
Interestingly, one of my Mitsubishis had a line leak at...........right around 7 years. I use mine the opposite of you.
IN most markets there is at least one medium-sized (more than one truck) HVAC company that everyone in the biz knows is the best. They typically charge double what everyone else charges, but they train their techs well and pay them enough to stay around for a while. They typically don't pay the techs a % of everything they sell like the bigger ones and equity-owned ones do. Sometimes you can get their name from the local supply house.
As far as leaks; are you talking about water leaks or refrigerant leaks? Finding either one is a chore but a different chore and you do need a pretty good technician to accurately find it. You don't want to replace the heads if there's a leak in the lineset and vice-versa.
FWIW I am going through the selection process for my own home right now. My engineer specced Mitsubishi but I'm pretty sure that's just because Mitsu gave him a fancy binder at some conference or another. I am strongly leaning towards a private label manufactured by Midea. They seem to just have a wider selection, better specs and a better warranty. My local HVAC guys says he has been installing them for years without any major complaints. We'll see.
Hi Peter,
The leak is refrigerant. I will save you the full 3 year saga of leak diagnosis and just say that ultimately florescent dye was added and I was able to identify the location with a black light so I am pretty confident that the air handler coil is the problem.
You should buy a 410a unit. The line sizes will be different on the new refrigerants. If you are handy, I would just get an off brand split, something like:
https://www.alpinehomeair.com/product/air-conditioning-cooling/ductless-mini-splits/single-zone-mini-split-systems/blueridge/bmkh1824?linkfrom=froogle&campaign=61108680&adgroupid=1833640080&product_partition_id=466402265726&keyword=&matchtype=&device=m&content=714669832716&network=g&gclid=CjwKCAiA9vS6BhA9EiwAJpnXw61BKyOzc0Y3hFN0nZ6Cri4JA2VI4IDkYau3souReC64ImLin0-nUBoCXlEQAvD_BwE&gad_source=1&gbraid=0AAAAAD_tWfY712Vc7A0r3W5JWKsYdrTz4
I have had a couple of these units installed for about 8 years without issue. I’m sure they are just a Midea or something similar rebranded but they are pretty close to the cost of just the indoor head on a Mitsubishi.
Thanks !
The Blueridge unit you linked to is indeed a pretty substantial savings vs the Mitsubishi unit. Very tempting.
"You should buy a 410a unit. The line sizes will be different on the new refrigerants"
Had not heard this. Upsizing on line sets, I assume ? How much bigger ? Copper is pretty expensive these days.
I had the same thing happen on the one Mitsubishi unit I installed. Couldn't find the leak. Finally, you could hear the leak on the head inside one day.
Everything else I've installed has been a Fujitsu. Honestly things go on both of them. I've had a loud indoor fan motor on a Fujitsu unit recently. Also a blown circuit pour it on an outside unit. Granted that was a know issue.
I think they are all about the same. The app system is better on Mitsubishi. Otherwise I tend to like the Fujitsus better for a single system. Mitsubishi for multi. I think Mitsubishi is selling the outdoor defrost coil separately from the unit so that the energy rating isn't including it. It's included in the Fujitsu. I could be wrong but I think thats how that works.