Cheap Chinese Mini-Splits: Worth It?

IHDiesel73L · Aug 5, 2018

Seems these days that the market is flooded with cheap Chinese mini-splits with a million different names (my guess is that they are made by a handful of manufacturers) that are skewed to the DIY market.* Unlike the major brands like Mitsubishi, Sanyo, etc...which usually carry a disclaimer of "warranty will not apply unless installed by a licensed technician," they are marketed to be installed by a DIY'er who then goes out and hires an HVAC guy to vacuum and charge them.* I'm curious to hear from anyone who has installed one of these "off brand" units and how they fared.*

We have a 2600 SF house that is a mishmosh of original construction and additions going back about 200 years.* The good news is that the previous owner put a large second floor addition on in 1998 with a walk up attic.* I have plenty of room to mount concealed duct units to feed the six rooms that need cooling up there.* I plan on using a three zone system, probably 36K BTU, and splitting the supply and return for each with short runs, each unit serving rooms that are adjacent.* I'm also planning on locating a heavy duty whole house dehumidifier in the attic as well with one supply on one end of the house and one return on the other end of the house for a few reasons.* First, I've read a lot about how supplemental dehumidification can really take a load off of your AC units, second, humidity, rather than temperature tends to make our house the most uncomfortable.* We are pretty deep in the woods with substantial shade to the south, so as long as the humidity level is low, the house is pretty comfortable, even on the second floor up to about 85°F.* On the other hand, when the humidity level is high, it can be pretty miserable in the mid 70s.* The downside of course is that dehumidifiers heat the air somewhat, but the two working in tandem with the dehumidifier handling most of the moisture removal and the concealed duct units simply cooling the air, should work well.**I'm only going to do the upstairs this year, so perhaps there will be lessons learned before I do the downstairs.

GLyford · Aug 8, 2018

I've not seen a mini-split that runs with a ducted system, so are you asking about two different types of units here?

All the mini splits that I have seen have a compressor unit (most will run 1, 2, or 4 heads, though I think there are others). The head units mount on the wall inside the room being cooled and vent directly into the room they are in, the connections from the head units to the compressor are both coolant and power, all power is fed into the compressor unit, there is no air duct, just an intake on the top of the head unit in the room through a dust filter and an exit on the bottom with a dispersion vane. If you need to cover multiple rooms, the best way is with multiple head units, there is no easy way to have one head unit feed several spaces that don't already have good mutual air circulation. I have a fairly open downstairs cooled by 2 head units because 3 large wall openings are not enough air circulation to coll both sides with one unit.

One bonus of multiple head units vs. room on shared duct zones is each room can be controlled for temperature separately, essentially each head unit is its own zone. Our units have a mode where they mostly run as a dehumidifier themselves.

Mini splits are less like a conventional ducted AC unit and more like a window AC in how they operate, just that the distance from the inside cooling portion and the outside heat exchanger/compressor is extended by the line set allowing them to be mounted at different heights, around corners, etc. If you figure out how to run the lines there, you probably could mount a head unit on an inside wall, but usually they are mounted directly on the exterior wall, and about a 3x3 utility run carries the line set and wiring between the units.

I cannot speak to the quality of the DIY units, my Mitsubishi was pro installed.

IHDiesel73L · Aug 8, 2018

GLyford said:
I've not seen a mini-split that runs with a ducted system, so are you asking about two different types of units here?

The concealed duct units are relatively new-they are more like a conventional split system in that you have an outside compressor and an indoor air handler that is hidden either in the attic, under the floor, or in a soffit/ceiling. The advantages over a conventional split system are that you get an inverter variable speed compressor which is much more efficient just as you would with wall mount mini splits, and the air handlers are very compact and able to fit into tight spaces. Here's an example:

ovrszd · Aug 8, 2018

That's what I have plus a mini split in a basement room. Works fine.

To the thread subject. Cheaper is NEVER better. Whether it's comparable will only be determined by time. And by then it's too late.

man00 · Aug 8, 2018

I'm not so sure if there is any real difference in quality with any of the HVAC units..It's mainly about the if the company stands behind their product, installed properly. From what I seen with some of the DIY packages later down the road they tend to leak

GLyford · Aug 9, 2018

IHDiesel73L said:
The concealed duct units are relatively new-they are more like a conventional split system in that you have an outside compressor and an indoor air handler that is hidden either in the attic, under the floor, or in a soffit/ceiling. The advantages over a conventional split system are that you get an inverter variable speed compressor which is much more efficient just as you would with wall mount mini splits, and the air handlers are very compact and able to fit into tight spaces. Here's an example:

View attachment 565960

That's cool! (pun not intended...but I'll take it)