Opinions about ductless mini split heat pump systems

42 Replies

I am tired of buying window air units. I generally buy and hold SFRs built from the 1920s-1960s. Most do not have central heat and air systems. I have put in a couple full central systems and it has been too expensive for the return. I like the idea behind the ductless systems but am worried about the quality, ease of installation and maintenance. I have zero experience with them so all opinions are welcome!

I will have my licensed hvac guy install the first one but I am hoping to be able to do them myself at some point.

Thanks in advance.

i love these type of units, energy efficient and soooo quiet. You will totally be able to install yourself but might need someone to charge after install.

If you already have forced air heat just do what you've been doing and use the existing duct work. These are great when you want to keep a hot water/radiator heat system, not run ducts, and get your A/C.

I have installed 2 Fujitsu Split units in rentals.  They are common for years in other parts of world (I see many in Europe where the heating is often primary radiators (no ducting) with Splits providing supplemental heat and AC).  I therefore believe the technology to be established and the units to reliable. 

The two I had installed were 4 or 5 years ago and they work great and were reasonable cost.  One was for a 4/2 (1500') and the other for a 3/1 800' (it is really 2/1 with bonus room that tenants use as a bedroom).  Both of the tenants love them.

However, I recently got a quote for 2 different rental units from the same contractor as did the other install and the price was significantly higher than previously (over twice as much money).  I question if my HVAC person simply has more work now and can charge a premium.  The 2 new units are to be put in 2/1 of almost 700'.  The quote was over $6K each (my 4/2 unit was less than $3k 4 or 5 years ago).

In summary I think they are a good solution especially where ducting would be difficult.  However, I am not going to pay $6K to get it installed per my most recent quote.  I may seek other quotes or look into the feasibility that my handy man could do the install (he is only an OK handyman, I used to have a great handyman (that I would trust for this installation) but his Mom had a stroke so he does very little work for me recently).

If you go for the self install I would be very interested in the details.

Dan is right. These things are everywhere in China for example. In northern China, government housing is built with central heating. In the south, no such thing. In Shanghai, (just south of the decision line) you'll see these little split systems hanging outside almost every apartment. Everyone has one or more -- one per room-- and they just work. Most popular brand seems to be Panasonic just by my unscientific inspection. Maintenance is cleaning the self contained air filters every so often. I used to think that the line length was an issue in heat pumps, but these are routinely installed with ten meters of pipe between the in- and outside units. Inside device has a remote control to set temp and air speed. This seems to be well-proven technology. Ken Jones, Seattle.

@Dan Heuschele

Are you putting one of the interior units in each bedroom and then one in the living room? Do they work well enough that you do not need to put one in every other non living space (i.e. bathroom, kitchen)?

How efficient is the heat on these?

How long does a typical system last?

I have a 2/1 and a 3/1 that uses window units and a boiler with in floor heating.  The boilers are getting up there and will eventually need to be replaced.  These might be a better option then replacing the boiler and replacing the pipes if necessary or switching to forced air.

Thanks everyone for the responses. I am very excited to give these a shot. @Kenneth Jones thanks for the info on the piping. That is one of my big concerns. @Dan Heuschele I will be ordering a system this next week and will report back on how it goes with the install. ( After some more research, I think I am going to go ahead and install this one myself).

@Matt Holmer

They sell units with multiple interior units with one exterior unit and I have seen some of these in Europe but the two I had installed were single interior.  The 3/1 unit had a 12K BTU unit.  I think the 4/2 had a 24K BTU (it was ~5 years ago) and required an extra drop from the utility company and a new panel. 

With one interior unit they work best with open floor plans but neither of my units are very open.  For bedrooms to get any significant cooling the doors must be open.  For more money you could opt for multiple interior units for better heat/cooling of the bedrooms but at some point the cost will start to approach forced air HVAC.

I think the tenants are mostly happy because they went from no AC to having AC.  A big reason I put them in is that the 4/2 had 2 wall type heaters and one had been flagged as dangerous by the local utility company.  So I was going to be either repairing or replacing a wall heater regardless.  There was no existing ducting due to the heat being via the wall heaters.   The wall heaters have the same issue with heating bedrooms (i.e. they heat the bedrooms best if the doors are open).

I think the need for multiple interior units depends on the expectations of tenants.  Where most of my units are (Escondido, CA) it is hot but the tenants do not expect air conditioning.  I have one unit with a new (1 year old) AC (fairly efficient) that they do not use the AC due to the cost. 

The 2 units I am considering installing Splits into now not only do not have any ducting but they have no attic (vaulted ceiling everywhere which adds to the heat issue).  They both have a single wall heater for heating.  So a central interior split would match what they currently have for heating and would provide them some AC.

I have installed several of mini split systems They are very easy to install. If you get one get a inverter one it changes the speed of compressor to use less power. If you get at least a 16 seer the heat out put is very good. They come pre charged with freon but it is best to pull a vacuum on line before opening valve to release freon. The only bad thing is the water condensation line make sure you clean it out once in a while, if it gets plugged the water comes out inside all over wall

very easy to install,  will require the purchase of some tools ( gauges, vac pump and adaptor for r-410, make sure you get r-410 gauges )  i bought mine on the net, with free delivery from http://www.thermospace.com they are cheapest that i found.  Another thing to consider is 2 separate units are cheaper than 1 muti unit. ( 2-1ton units are cheaper that 1- 2ton unit)

@Richard Russell , @Bryan Kopa , @Dan Heuschele , @Paul Choate , @Al Williamson , @Will G.

Are you all still in favor of these systems?  I have a condo in Los Angeles where I intend to reside and am looking into this.  Central is not an option.  Currently has no cooling, and has radiant heating in the ceiling in some rooms (recessed lighting installation ruined it in bedrooms...).  Would appreciate any feedback.  I am looking at $5-$6k in part due to some drywall cutting we will have to do in a hallway and the plan is to remove/modify/replace crown molding to run the tubes behind it.

Also - anyone had potential tenants or buyers be turned off by the appearance issue of having the interior units?

@Marco G. my tenants are happy to have AC and therefore do not complain about the appearance.  I have used them in 4 rentals (4/2, 3/1, 2/1, 2/1).  The biggest issue is that tenants do not clean the filters as often as they should which can result in a more extensive and costly cleaning being necessary. 

Overall I would choose this option where there is not existing ducting.  So your use with radiant heating would qualify as a situation that if I were to add AC I would first look at the Mini Splits.

Another gotcha is make sure your electrical can handle the expected load.  In all 4 of my installs the electrical needed to be upgraded which increased the cost to add the Mini Split HVAC systems (one cost for the system and an additional cost to upgrade the electrical). 

Good luck

My neighbor is a hvac contractor, and mini splits are all he uses on his 2600 sf home. According to him daiken is the best and most expensive and gree makes a decent more competitvly price unit

We have two Halcyon units in our home in GA. We had three until about 10 months ago (see below). We are generally displeased with them because of the extraordinary amount of cleaning they require. The indoor units get moldy very quickly. Then they constantly spew mold spores all over the room. The coils and fans become very moldy and nasty. We are on a schedule to clean them every 4-6 weeks. It's an ordeal to clean them. We have to remove the cover, drape plastic underneath the unit to guide the cleaning solution and rinse water into a trash bin. The mold gets attached to the coils and fans and can only be removed by fairly high-pressure water. High humidity probably exacerbates the problem.

The mold these units spew have caused health problems for my family and pets. I estimate that we've spent a few thousand in medical bills as a result.

When we asked Fujitsu about the mold issue, the said that we should hire a contractor to come clean the units regularly. Imagine spending $200 a month to have someone clean these units!? That will eliminate any costs savings you might expect from reduced electric bills.

The 9RLS system has a serious temperature control issue, as well. The indoor temperature sensor is located right on top of the evaporator coil, so it's influenced by the coil's cool temperature. Usually when we set the cooling temp to 64F, it would stop cooling when the room was about 74F. Finally, after years of struggling to get it to cool the room, I removed the sensor and routed it outside the unit so it is exposed to the room air behind the unit at the top. After this modification, it will will FINALLY cool the room effectively.

Overall, not a wise investment.

We replaced one in the bedroom with an LG unit about 10 months ago. Amazingly, this LG unit stays clean. It's one with the self-cleaning setting. It is SO much better than Fujitsu. I will soon replace the other Fujitsu's with LG units.


The unit we like: LG LS120HSV4

I have no relationship to either manufacturer.  This report is based solely on our experience.

@Brad Isley

Since you are replacing them with different ductless systems, would you say your problem is with a specific unit? Or do you have so much sunk costs that you are sticking with them?

What is your experience with installation and maintenance other than mold issues and the sensor?

Each of the Fujitsu units were different sizes and models.  They all function as mold distribution units.  They drip water on the fan, causing a growth of mold.  After a couple months, the fan is covered in mold streamers.  Mold grows on the coil.

The remaining units don't run as much, and we're undertaking some other renovations,  so we've decided to delay the replacement.  The cleaning regimen is not as much of a hassle on the two remaining.

So far after 6-7 years, maintenance has been just cleaning filters, coils, and fans.

Installation was not difficult.  If you can do basic wiring and minimal carpentry, it's a breeze.  Routing the refrigerant lines was the most difficult part of the installation.  Find a friendly helpful AC person to come by to pull a vacuum and release the charge when you're done with everything else.

The LG unit's self-cleaning cycle dries the coils on a schedule.  This greatly reduces the mold problem.

Big believer in these! I've had 18 mini splits installed in my previous residents, rentals & commercial properties: Sanyo, Union Air, Fujitsu, Mitsubishi, Panasonic, Comfort Aire, Daikin, Soleus Air.  Daikin have been the most reliable.  The 16+ seer models run super efficient and I've always had single head unit, as when the outside compressor fails, it doesn't take down a whole multi-headed system which I'd been counseled against by several experienced AC installers.  

Multi-headed units (w/ a single outside compressor) often require a special higher amp circuit.

Just had one installed here for a tenant during a heat wave.  They run it in a bedroom and have a fan in the hallway to cool off other rooms.

The units require more recharge and cleaning maintenance than ducted systems, but they seem quieter inside and outside from the larger central systems.

@Brad Isley @David Davidson @Kiersten Vance @Dan Heuschele @Richard Russell @Bryan Kopa  

I am looking to replace the window units in a small brick duplex with a multi split ductless system which seems like a common thing to do.  Since our tenants cover electricity, the window units usage fell under their respective electric bill.  How do you handle that with the multi split system?  Is there a meter you can install for each split?  Do you use a ratio based utility system?

Does anyone have experience on how well  they heat for those of us in snow country? I have considered these as a replacement for radiant electric heat both for efficiency and because they would eliminate putting in the window AC unit and theoretically be more cost efficient then my electric heat.

With my background being in the hvac field. I can tell you that these units are awesome. Super quiet, efficient, and can heat or cool areas large or small. You also have many different styles of indoor units you can install from wall mount, recessed ceiling units, floor mount, ducted and others.

But buyer beware, buying the cheapest unit on the internet may work out for you but they say you get what you pay for for a reason. Mitsubishi has given me the most reliability, then take your pick from there. Daikin is okay, LG,Samsung, Fujitsu are cheaper options but I also have had to do more service calls on these brands. Now this may just be my luck of the draw, but a good installation is the key to longevity of any mechanical cooling or heating appliance.

So I do highly recommend ductless heat pumps but do your research as you should with all purchases like this. If you want heat and it gets cold in your area. Make sure the units heating capacity is adequate for the space being conditioned when the temperature gets cold. Some of these units will lose capacity at 30 degrees some at 10 degrees. They all vary but whatever brand you decide on just ask for some assistance on getting the right unit for your situation.

They heat very well. Most are 100% efficient down to 0 degrees. Just make sure it's raised off the ground either on a bracket or a stand. They won't work if they are covered in snow.

Free eBook from BiggerPockets!

Ultimate Beginner's Guide Book Cover

Join BiggerPockets and get The Ultimate Beginner's Guide to Real Estate Investing for FREE - read by more than 100,000 people - AND get exclusive real estate investing tips, tricks and techniques delivered straight to your inbox twice weekly!

  • Actionable advice for getting started,
  • Discover the 10 Most Lucrative Real Estate Niches,
  • Learn how to get started with or without money,
  • Explore Real-Life Strategies for Building Wealth,
  • And a LOT more.

We hate spam just as much as you