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Daikin vs. Mitsubishi Minisplits

Jaccen | Posted in Mechanicals on

Hello,

I was wondering if the good people of GBA could provide their opinion on a couple of mini splits set for installation.  We had a local engineering firm use Wrightsoft to size our equipment.  We had Fujitsu units spec’d as we believed they had about the best bang for the buck.  They also allowed vertical installation of the ducted unit for the 2nd floor.

The brief details are the following:
Location: between London and Kitchener, Ontario, Canada (ie. Zone 6)
1rst floor: ~1500 sqft
2nd floor: ~1300 sqft
1rst & 2nd floor insulation: R-23 continuous exterior, R-22 batt interior
Attic: R-100
Windows: U value 0f 0.20
Anticipated leak test: ACH50 between 1.0 & 2.5 (hopefully better)
Backup heat: Panasonic heated exhaust fans for bathrooms, electric fireplaces in basement & 1rst floor, and an inline heater for ERV supply runs for emergencies (property has access to multiple, routinely fuel stocked, large generators as it is agriculturally based so the house is all electric)

Per the attached plan, the following Fujitsu models were spec’d:
1rst floor ductless: 18RLXFWH – AOU18RLXFWH (outdoor) w/ ASU18RLF (indoor)
2nd floor ducted: 9RLFCD – AOU9RLFC (outdoor) w/ ARU9RLF (indoor)

Specs for easy reference:
https://www.fujitsugeneral.com/us/resources/pdf/support/downloads/submittal-sheets/current/18RLXFWH-2019B.pdf
https://www.fujitsugeneral.com/us/resources/pdf/support/downloads/submittal-sheets/current/9RLFCD-2019B.pdf

Unfortunately, due to labour shortages and supply issues, we are unable to install Fujitsu units.  We have the following options available:

Daikin:
These are our most readily available units and what our installer is most familiar with.
RXL18UMVJUA (outdoor) w/ FTX18UVJU (indoor)
RXL12QMVJU (outdoor) w/ FDMQ12RVJU (indoor)

Spec sheets:
https://www.daikinac.com/content/assets/DOC/SubmittalDataSheets/Single-Split/FDMQ18RVJU-RXL18UMVJUA-Submittal-v1.pdf
https://www.daikinac.com/content/assets/DOC/SubmittalDataSheets/Single-Split/FTX12NMVJU-RXL12QMVJU%20Submittal%20Sheet.pdf

My primary questions are:
1. Does anyone in a Zone 6 setting have experience w/ Daikin units in the cold?  They are spec’d to -13°F for heating (similar to the Fujistu’s) and seem suited well enough based on weatherspark data ( https://weatherspark.com/s/18239/3/Average-Winter-Weather-in-London-Canada#Figures-Temperature )
2. Has anyone ever mounted a Daikin ducted indoor unit vertically?  That was one of the reasons we went w/ Fujitsu over Mitsubishi.  If they cannot be mounted vertically, it will make ductwork fun on the 2nd floor.  I have contacted them, but getting answers to technical questions seems to be difficult anymore.
3. Any comments or concerns over the Daikin brand?  My research shows they are considered one of the better brands out of Japan, but real-world experience is always appreciated.
4. Project has a 2″x8″ service cavity above the 2nd floor.  Along w/ bulkheads, this was envisioned for electrical, low voltage, and HVAC.  While residential ducted heating is usually preferred in the floor for heating, how much of a performance penalty should one expect if the ducts are in the ceiling (ie. directed down instead of up)?  Another option is to run an interior wall bulkhead along the central wall by the stairs and route the ducts by the joists.  It would just make things a bit more fun as the cabinets have been set there and would need to be changed.  Opinions as to which is a better option are also appreciated.
5. Any insight as to spec’ing pan or aux heat w/ these?  I’m not as familiar w/ this brand in that regard.
6.  Any recommended accessories?  I know many recommend separate thermometers for the Fujitsu and Mitsubishi units.

Mitsubishi:
These are really only the backup option as the installer strongly prefers Daikin.
MUZ-FH18NAH2 (outdoor) & MSZ-FH18NA (indoor)
SUZ-KA09NA-TH (outdoor) & SEZ-KD09NA4 (indoor)

Listed here for completeness, but I fully expect we’ll be going for the Daikin’s barring some significant “gotcha’s.”  Any opinions on them are appreciated.

Thanks again.

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Replies

  1. Steve Knapp CZ 3A Georgia | | #1

    I'll give your post a bump. FWIW. It's my understanding that Daikin is considered top-shelf equipment. (I had a Daikin ducted unit in my last home and really liked it. Currently retrofitting a Mitsubishi Hyperheat system into my current place.)

    I'd be more focused on insuring that the equipment is properly sized. Ideally, you want the system to run a low speed for extended periods. My personal experience is that approach delivers greater comfort. Many of the complaints I see online are generally the result of an installer putting in oversized equipment.

    1. PBP1 | | #4

      Yes, sizing is important and I think the OP has presented data that indicate the sizing is correct, in contrast to many that oversize.

      In CZ6, for 2800 sq ft, with that amount of insulation, ventilation may be a factor to consider. But 18k + 9k (27k total) seems about right. I have much less insulation for CZ6, 2100+ sq ft with Mitsubishi 28.6k (15k, 12k, 9k ducted), which had the house doing fine at -6F with wind this week.

      So nice to see a post with sizing that looks realistic ;-) And, looks like a great project too.

  2. GBA Editor
    Kiley Jacques | | #2

    To piggyback on Steve’s comment, sizing is king. This article from Martin explains why and how to factor it into your product selection: Choosing the Right Minisplit. He links to some helpful resources too.

  3. Danny Gough | | #3

    Over the years, I have specified Fujitsu, Mitsubishi and a couple Gree units. My experience is in Climate Zone 4. One issue that makes me a fan of Mitsubishi is the thermostat option. I have never had a homeowner who liked the proprietary thermostats from Fujitsu OR Mitsubishi. To me, they are a cruel joke. It was especially frustrating on homes that had a conventional heat pump on the main floor and min-split on the 2nd floor. That meant the thermostats were different on each floor. One owner even asked us to replace the mini split because he hated the thermostat so bad. A few years back, Mitsubishi introduced an adapter, PAC-US-444, which allows a conventional 24 volt "Americanized" thermostat. Then we use the Honeywell Prestige with on board control of the ventilation and humidity control. It's made life with mini splits so much easier. The HyperHeat units have performed very well. Im guessing Daikin has comparable performance. But I dont know about their control options.

  4. Jaccen | | #5

    Hi all. I must have forgotten to have email notifications clicked. Thanks so much for your input--it's greatly appreciated.

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