Powerwall Compatible HVAC

[Cstreet]

Are these compatible with ducted systems (Ie swap out existing NG furnace)? If not, do they make one that is?

Yes the Mitsubishi system has these ducted air handlers (Compare Products | Ducted Air Handler | Mitsubishi Electric) that swap into where our existing gas furnace was in the garage. And then they were able to get this slim smaller air handler in a small area above an addition (Compare Products | Horizontal-Ducted | Mitsubishi Electric). You might hear these being called pizza boxes .

We also later put a smaller heat pump with a wall mounted head into a small separate office in the yard too that works great. I looked at Mitsubishi and LG systems which seemed to be the best. They don't require backup gas or electric resistance heaters. Mitsubishi had the most flexibility.

 

[jboy210]

Why do they have to replace the ducting when you switch over to heat pumps?

 

[dareed1]

In our case the ducts were over 50 years old, installed in an unconditioned crawl space. I wanted to improve efficiency, and I knew these ducts had lost their insulation and had some leaks. The return air was handled by a single ceiling duct in a central hallway. We added a second return duct adjacent to the original one to reduce pressure drop so that the air handler can operate with less power consumption.

So it isn't necessary to replace the ducts, but in our case it was highly desirable. I would have done the same things if we had installed a ne gas furnace.

 

[clarus]

I have recently replaced my 100KBTU gas furnace with a Mitsubishi heat pump system and have done quite a bit of research on it. I opted for an air handler (SVZ 36K) to replace the furnace in the garage just to cover downstairs, and three ceiling cassettes (MLZ) for upstairs rooms. Main reason is that the ducting going upstairs is insufficient and mini-splits are more efficient. It also gives me individual control for separate areas. There are quite a few options to configure the system such that it will fit your house and preference. They have air handler (the furnace-lookalike units) of various sizes, ceiling cassettes, wall units for close to ceiling or close to floor mount, ducted concealed cassette etc. And they can be used in almost any combination to fit your space.
I have always been told that the heat pump would produce more gentle heat and takes longer to heat up the space. May be I have over rated all the units, I found that the new system actually heats up the space faster than before, especially upstairs. The amount of air that the system move is definitely higher than before. Or may be the previous set up was "defective". So far I'm pretty happy with the results. Need to wait till summer to test AC.
So far the most energy I see the system used is less than 4kwhr/hr, this is when the system first turn on in the morning. (the system turns off at night).
Also a word of caution for interested buyer, for those who are used to smart thermostat like Nest or Ecobee, the Mitsubishi control interface will be like going back to the 80s. Yes, it is workable, but the UI is pretty primitive, even their cloud apps. They do provide smart thermostat interface box, but then you loose the efficiency of the variable speed/power control and the system is dump down to a normal 2-stage or 3-stage traditional unit.

One thing I do want to check with fellow Mitsubishi owners is on the noise of the compressor. I have heard other units in operation and they are usually pretty quite. But mine is louder than I expected. I have a MXC-8C60NA2 outside and I measured almost 66db (C weighted) 3 ft from the unit. How loud is your outdoor unit? In addition, since the unit is tied the wall, it makes the wall vibrate at a low frequency (about 30Hz) that can be heard in the house.

 

[zƬesla]

@clarus – I have 2 Mr Slim outdoor units with 5 indoor heads. One of the outside units started sounding like a jet engine. Compressor went bad and was replaced under warranty (plus labor as original installer went MIA). Don't know about the ceiling units, but I have Raspberry Pis on each of the heads that allow me full control via web.