Floor-Mounted Fujitsu Minisplit
davidsmartin
| Posted in Energy Efficiency and Durability on
I am looking for a Fujitsu make a floor mount unit (they seem to call this “universal”) that is compatible with the AOU15RLS3H outdoor unit that continues to produce heat when it is minus 15 degrees F. Does that exist or do I have to get a wall unit with that outdoor unit?
I found a floor mount unit that works with the AOU15RLFFH but that seems to be significantly less efficient than the RSL3H series with a HSPF of 11 vs 13.
I would prefer the floor unit as I want to place it under a window.
I have a Fujitsu in another room and would prefer to stay with them if it is possible. Thanks.
David
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I would browse through here:
https://ashp.neep.org/#!/product_list/
The bigger issue with the Fujitsu floor mount is that it doesn't come with a pan heater. That is definitely something you want in a place where you are looking for heat at -15F. The floor mounts tend to be less efficient as they have different blowers and heat exchangers. Floor mounts are also not very popular, so there is a pretty limited selection of them.
There is also nothing wrong with putting a wall mount down low or even mount it inside a small alcove bellow the window.
I just put two Fujitsu AGU15rlf's in my house. I had the same situation in that the only place I could place a unit was under a window.
They look great. I kind of like the looks of the floor mount units better than the wall units now.
They do come with pan heaters, but supposedly only heat down to -5.
As I recall, low mounting produced an increase in Winter efficiency (because the intake air is cooler).
This is correct. I have both a floor mount and a wall mount. The floor mount unit is superior in heating mode to the wall unit as it has both a top and bottom discharge. It sends heat out across at floor level and the intake brings in the colder air down low.
Another benefit is the floor mount units are simple to take apart and clean the coil and fan. 4 screws and the entire front cover comes off.
Here is a FLIR picture of my floor unit and one during install showing the coil access. My floor unit is a Midea/Carrier Premier hyper heat. Its rated full heat at -5 and 69% at -22. It cost me a little over $1k and I self installed it.
Is yours a Fujitsu or something else?
Edit: Oh, I see you answered that question below.
Midea actually makes almost all the floor console units except for Mitsubishi. I cross referenced parts and specs and they are identical. Almost every manufacturer is using the exact same unit except Mitsubishi who is using their own design.
That's interesting. Mitsubishi's marketing documentation (source: https://www.bayareaservice.com/wp-content/uploads/2016/11/KJ-Product-Brochure.pdf) claims their mixing is better than a competitor.
Granted, it's marketing, but it'd be interesting to know what they're comparing against, testing methodology, etc.
It is disappointing that Fujitsu does not seem to make a floor unit that matches the efficiency and temperature range of the RLS3H series. I suppose the options are to put the wall unit under the window. It is so deep that it will look odd there unless I can find a way to hide it under a table without restricting the air flow.
The other option would be to go with a Mitsubishi or Daikin. Are their floor units better than Fujitsu?
Are you self installing or using a company? I have been really happy with my Midea /Carrier Premier floor console. When I researched floor units it had much better cold performance than all the big names and was close to half the cost. My unit was just over $1k delivered to my house. Midea is the largest hvac company and the world and makes the majority of the units out there. They teamed up with Carrier a few years ago so Carrier units are just rebadged Mideas.
I have the below floor unit. Its been running nonstop for 2 years with zero issues.
Midea MEHSU-12CHN2 Premier Hyper Console Indoor Unit 12,000 Btu/h
Premier Hyper systems are a primary heat source, with Hyper Heating down to -22F, and 100% capacity down to -5F. Available in 9 and 12k systems.
I'm suspicious that the differences in efficiencies are at least partially related to the test procedure which assumes a entering room temperature that is the same regardless of the configuration. The lower entering are temperature is probably a single digit change in efficiency in the real world.
Perhaps larger is the comfort advantage of the lower position. I've noticed with my high wall that I have to reset the space setpoint upwards to maintain equivalent comfort as it gets colder outside (didn't have to do this with my furnace with the thermostat in the same position). This probably has to do with the mean radiant temperature being lower along the floor.
The high wall units have a lower power fan that contributes to overall efficiency due to lower power distribution. I suspect the actual refrigeration efficiency is pretty close to identical.
With Mitsubishi there was about a $1000 cost premium to go with floor mount versus high wall. This seemed excessive, but I was told they don't move many floor mounts (KJ series) and they get a decent volume discount on the high wall (FH series).
According to the NEEP tables, the Daikin floor units are much more efficient than the Mitsubishi or Fujitsu at both 17 and 5 degrees.
Daikin VXS15NVJU COP is 2.7 and 2.4
Mitsubishi MUFZ-KJ18NAHZ COP is 2.1 and 2.0
Fujitsu AGU15RLF COP is 1.8 and 1.8
This seems like a significant difference in efficiency. Should I trust the figures? Is there any reason not to go with the Daikin if I get a reasonable quote? The same contractor who installed my Fujitsu also handles Daikin.
(I never answered an earlier question: I will have the system installed professionally. So the )
Daikin is a first tier vendor that gets somewhat better quality reviews than Mitsubishi or Fujitsu. It was at one time the worlds' largest vendor of variable refrigerant volume heat pump systems in commercial applications, more recently displaced by Midea (the largest Chinese vendor.)
So sure, to the extent there weren't any typos (there are a few in the NEEP site), it's fine to trust but verify those numbers and go with Daikin, assuming they are reasonably well supported in your area.
If you live in a IECC zone 5 or cooler climate it's worth going with a RXL15QMVJU compressor unit with a pre-installed pan-heater. The model number doesn't change with /without the pan heater, but be sure to specify whether you want the pan heater (or not.)