Replies

1. 
   norm_farwell | Nov 17, 2019 08:00pm | #1

   See comments section:
   https://www.greenbuildingadvisor.com/question/mini-split-for-winter-heating

2. 
   willymo | Nov 19, 2019 11:30am | #2

   Thanks, that helped me find some of the info. I looks like the remote can be set down to 50°, and the wireless thermostat as well. I have not been able to verify this for the wired thermostat.

   My contractor is advising the wired thermostat, saying that the wireless is less reliable. Does anyone have experience with this, one way or the other? Also, are there any capability differences between the wireless and wired thermostats?

   Bill

1. Expert Member
   BILL WICHERS | Nov 19, 2019 12:35pm | #3

   I’m sure this was just recently asked. This post was like deja vu for me :-)

   Wired thermostats are always going to be more reliable. If nothing else, you avoid the “low battery” issue with wired thermostats. The downside is obviously the difficulty of running the wire to wherever it needs to go.

   I personally try to only use wireless devices where I absolutely have to. This goes for computer stuff, alarms, pretty much everything. Wired devices just have less problems.

   Bill

3. 
   willymo | Nov 19, 2019 01:06pm | #4

   Thanks, Bill, that's very helpful. Do you know whether the wired thermo can be turned down as low as 50°?

1. Expert Member
   Dana Dorsett | Nov 19, 2019 01:40pm | #5

   There are at least three wired remotes compatible with the FH06.

   The MHK1 can be set as low as 40F in heating mode. See page 2:

   http://meus1.mylinkdrive.com/files/Application_Note_3021_-_Wire_Length_Limitations_-_Rev_20100801.pdf

   The PAC-YT53CRAU (originally developed for their City-Multi VRF systems) can also be set as low as 40F.

   http://meus1.mylinkdrive.com/files/PAC-YT53CRAU_Submittal.pdf

   I don't believe that's the case with the (older) PAR-31MAA (or other PAR series remotes):

   http://meus1.mylinkdrive.com/item/PAR-31MAA.html

4. 
   AndrisSkulte | Nov 21, 2019 01:02pm | #6

   For reference, the IR remotes included with my FH06's and FH09's let me set heat down to 61°F...

1. Expert Member
   Dana Dorsett | Nov 21, 2019 01:31pm | #7

   >"For reference, the IR remotes included with my FH06's and FH09's let me set heat down to 61°F..."

   If you use the SMART SET mode you'll find that they can be set as low as 50F.

1. 
   AndrisSkulte | Nov 22, 2019 03:15pm | #8

   Dana - Cool! (Pun intended, working on my dad jokes). I'll have to take a look.

   Has anyone used a Cielo Breez to control the FH's? $80/$120 price point is appealing vs $270 for the MHK1's.

   https://www.cielowigle.com/cielo-breez/

1. 
   Yamna259 | Feb 06, 2020 02:41am | #9

   Hi Guys,
   So I had been facing a similar situation & found the solution with another controller offered by the same manufacturer called Cielo Breez Plus. It is also a Smart Wi-Fi AC controller that comes with both global & on-device controls. It has two powering options; 5v adapter or can be hardwired if you want.

   Coming on to the situation at hand, I wanted to keep my setting between 45° & 55° too for anti-freeze purposes. Breez Plus gave me an option/feature via its app called ‘Comfy Mode’ that let me set temperature triggers to regulate my indoor environment. How it worked was it asked me what AC settings I’d like to set if my AC went below 45°. I set it to trigger on heat mode at a high fan speed with temperature set above 55° so that when it reaches over 55°F you can trigger it to turn the AC off bringing it back into the specified range.
   Once you’ve set these triggers the device does the rest for you and the entire process becomes automated triggering actions on your AC on its own when needed.
   The range it allows for is min 40°F max 95°F...

   Here is a link: https://www.cielowigle.com/cielo-breez-plus/

5. 
   norm_farwell | Feb 06, 2020 06:47am | #10

   According to everything I've seen Mitsubishi FH series minimum set point in heating is 50 degrees (not 40--there's a little footnote on that mhk1 doc that says min setpoint depends on equipment.)

   I got confirmation of this at a manufacturers training a couple of years ago when I asked about it. There was even a suggestion that these units might have difficulty accurately maintaining such a low set point because those low evaporator input/output temperatures are at the extreme end of what the refrigerant can handle. It's counter intuitive that the machine would struggle to do what seems like less work, but thinking in terms of the refrigeration cycle heating at low interior temps is the same problem as cooling at low outdoor temps.

1. 
   joshdurston | Feb 06, 2020 09:25am | #11

   IMHO, you're going to be into diminishing returns with setbacks once you drop below 50f, and you might be risking freezing pipes that are in cold corners, etc.