Why should I avoid a mini split?

I'm not an HVAC guy. But I am a competent tradesman. 
 

I have 2 projects underway which seem to lend themselves to mini splits. One is an a 2 story addition to my own house, and the other is a lake house with a 2nd story loft we are hoping to flip. 
 

My partner has lived in countries where mini-splits are typical, and she likes them. 
 

Ducted HVAC systems are running $10-12,000 for each house from a competent contractor. Looks like a DIY ductless system will cost me less than $4000 per house (each house will require multiple heads and about 3.5 tons of cooling). I'm in the South- cooling is definitely a bigger issue than heating. Both houses are well insulated. It's hard not to consider them if I am saving $16,000.  

Our house is a forever home. But we don't mind the ductless systems. There is the possibility that a ductless system would effect the resale value of the flip house, but it's a vacation getaway house. I think buyers are a bit more flexible on a house like this (the original owner went 40 years without HVAC).

What am I missing?  Other considerations?

Please discuss...

Downsides that I'm aware of after 2 summers of them in my parents lake house: 

1: Can be louder than central AC (but way quieter than a window or portable unit)

2: A little bit of an eyesore. Eyesore isn't the right word, it's way too strong. But you get my point.

3: Slightly less efficient for some applications... but this loses the argument when you consider that you can cool one room at a time rather than the whole house. 
 

I really like them and am strongly considering them for my own home. None of the downsides above are more than "yeah, I can see how that may be a downside. Still a good option"

Edit: also, my sister in law likes it about 64-66. I like it around 67-72. My parents like it 70-74. We all get our desired temperatures in the bedrooms at the same time. It really is a wonderful thing. 

You're missing nothing. I like Mitsubishis. HVACDirect sells them. The higher SEER ones are a visibly newer design than the older ones and have a better UI. 

You'll want to buy the Spin flare tools to install them and crowfoot wrenches. You'll also want an indoor unit cleaning kit.

They're fine for what they are.

They're cost-effective to install.  That's why you see them everywhere in retrofit applications, both residential and commercial.

They are not elegant... but they are better than window whackers.

Efficiency has come a long way in the last 10-15 years.  And, as noted, you can run them based on local occupancy rather than a whole house or whole floor.

Around here I see a lot of Mitsubishi units but I hear good things about Daikin from engineers.

In reply to chaparral :

Does that mean I'll need to hire someone to charge them with coolant?

In reply to Duke :

"For what they are..."

I get that. Not everyone wants them. But both these houses are vacation properties, and I think that's a different mindset. 

We put an MBR suite addition on our house, and it was not practical to extend the ductwork from the existing HVAC to the addition, so we installed a mini-split as the only HVAC in the addition.  If I had to do it over again I would pay the extra to have a regular ducted system put in.

Pros:

• Very quiet in cooling mode
• Very efficient (we got a 26 SEER one, specifically Mitsubishi MSZ-FH12NA)

Cons:

• Quiet in heating mode *except* depending on the weather every hour or three it decides it needs to defrost the outside coils so that it runs in cool mode to heat up the coils.  This involves humming from changing the vent direction, wooshing of refrigerant, and changing the inside fan speed.  I can sleep through almost any almost-continuous noise, but the sudden change and great variety of noises can be disturbing.
• Heat blows warm-ish air not hot like a gas furnace (true of any heat pump, not just a mini-split).
• I have it set on schedule, every time there is a power glitch the main unit forgets the schedule (or the time, not sure) so I have to re-send the schedule from the remote (maybe other brands or models are better?) before it starts following the schedule again.
• YOU HAVE TO CLEAN THEM.   At least once a year, if not more, and it is not easy.  The fan in the wall unit gets gunked up with crud, and dust accumulates in the coils.  How difficult this is varies with brand, and possibly newer ones are better (ours is 4 years old).  My FiL has a Bryant that it seems you cannot remove the fan from, so he reaches up from underneath with a brush to clean it.   I did that a couple times on ours, recently I found a video showing how to get the fan out without too much disassembly.  I saw a video for a newer bryant where the whole fan and motor drops out the bottom after  undoing a few clasps, so it may be much better now.  No one warns you of this, the manual makes no mention of cleaning being required, and it definitely doesn't tell you how to easily get the fan out.  Have no idea why the fan on a regular furnace doesn't get like this, but it definitely happens on mini-splits to the point of them not working right.

Did I mention that cleaning them is a pain?

BTW, the ducted system would be 15 SEER. The mini splits are 18-20 SEER. 

(I understand actual efficiency also has a lot to do with the construction techniques of the overall building envelope)

I think you have the perfect application for them.

I installed one in my garage in south Florida and could not be happier. Last weekend it was a lifesaver.

Mine is only noisy at startup when the fan is in Turbo mode (full speed), when its maintaining I need to look up to make sure it is on. Keep in mind its in a garage, but it is very quiet.

The application has so many cool options its insane, you can also use the control if you don't like to mess with apps. 

Make sure you opt for a heating strip if that is needed.

Here is my thread:

https://grassrootsmotorsports.com/forum/off-topic-discussion/garage-mini-split/182808/page1/

It came all precharged and it was quite a simple install.

Also, the right outdoor unit will support multiple indoor units. And you can install ceiling cassettes if you do not like the looks of the regular ones:

In reply to alphahotel :

Does your mini split have a filter on it?

BTW, mine has heat but I only tested it once for a minute, so I cannot comment on that side of things.

In reply to Slippery :

Good info

SV reX said:

In reply to chaparral :

Does that mean I'll need to hire someone to charge them with coolant?

No, they come pre charged. 

In reply to alphahotel :

Noted on the cleaning. 
 

It sounds like some of your bigger issues are with the heating. That's a non-issue for me (we don't even have any functioning heat in our house at all)

Price just came in on the ducted system for the flip house. It's not $10-12K. It's $18,200.

That may have made the decision for me. 

When doing the 1000sf (typo corrected) addition at the Farmhouse I wanted a larger than necessary (essentially 50k btu) mini split that would have three outlets two on the addition and one ducted to the garage where I could appreciate the benefits in the winter and summer. 

My builder and AC guy talked my wife out of it and I ended up with a second HVAC central air system for a single room. 

Do the mini split. 

mtn said:

3: Slightly less efficient for some applications... but this loses the argument when you consider that you can cool one room at a time rather than the whole house. 

I like to point people to the giant blower fan inside most central A/C systems.  Not only does it draw a significant amount of power, it also generates and adds more heat to the system, reducing its efficiency.  Pushing air through ducts is very inefficient.

In reply to QuasiMofo (John Brown) :

I'm honestly thinking that a lot of AC guys talk people out if the mini splits ONLY because they make more money on the ducted system. 
 

Were you really gonna add 50,000 BTUs for 100 sf?

In reply to prodarwin :

There is also thermal loss through every joint and every foot of ducting (which is frequently run in unconditioned space)

Mini splits don't have that problem. 

SV reX said:

In reply to QuasiMofo (John Brown) :

I'm honestly thinking that a lot of AC guys talk people out if the mini splits ONLY because they make more money on the ducted system. 

I think you're onto something here. 
 

I really see no discernible downsides to it for this application. 

SV reX said:

In reply to QuasiMofo (John Brown) :

Were you really gonna add 50,000 BTUs for 100 sf?

1000 sf.

SV reX said:

In reply to QuasiMofo (John Brown) :

I'm honestly thinking that a lot of AC guys talk people out if the mini splits ONLY because they make more money on the ducted system. 
 

Were you really gonna add 50,000 BTUs for 100 sf?

It was a typo. The room is 1000sf with a tall vaulted ceiling. It also feeds into the kitchen. 

And yes, the HVAC guy essentially added $15k to the $10k budget for the mini split setup by helping my wife choose the "easier to use system" 

In reply to mtn :

The AC guy trying to sell me the ducted system has his spiel down pretty well. "You're gonna need too many units". "The system won't balance".  "They are ugly".  "They will lower your property value".  "Would you want to walk from 1 room to another and have it be too hot?".

My favorite was (as he pointed to a toilet closet) "I don't want to be sweating when I'm taking a crap".  I thought that one was a riot. The toilet closet was in the middle of the house (surrounded by conditioned rooms), and had a vent fan to the outside (which means it would draw in conditioned makeup air).

Ducted systems are installed with filters before the fan and coils, thus they usually don't get dirty/dusty.

Mini-splits are great in many applications.  I see many in vacation properties.  

I didn't realize they had a cleaning requirement.  I need to research that more.  never thought about it... do they have filters inside?

In reply to QuasiMofo (John Brown) :

"Easier to use..."

HVAC guys are gonna have to watch their step with this one as younger people come up. My partner is quite a bit younger than me, and she LOVES her apps.  The idea that she could run all the mini splits from an app on her phone thrills her. 

A couple of things: Most old-school  domestic brands have SEER ratings from 14 to 18 and deluxe offerings which cost an arm and a leg, which will get you into the 20s. With mini-splits, SEER ratings over 20 are the norm, and some push 30. One guy mentioned them being loud.  That has not been my experience. Garden variety domestic ACs and heat pumps are around 70 db for the outside component. Most  mini-splits are in the 50s to low 60s. That's a HUGE difference. We've worked a lot with Mitsubishi, Fujitsu, Daikin and Bryant, and they've all been good. Most of them are Japanese or Chinese companies who are making partnerships with American brands: Mitsubishi/Trane, Daikin/Goodman, and Bryant/Carier/Medea to name 3.