Comparing Mitsubishi mini-split indoor units

[LeAnn]

Hi! I'm new here. I searched the threads for information on Mitsubishi ductless mini splits but didn't see an answer to my question. If it has been answered, please point me to the right thread.

I have two quotes from Diamond Mitsubishi installers to install a new ductless system in three areas:

* basement finished this summer
* planned bedroom being built under an existing sunroom (will be connected to existing basement)
* existing sunroom over planned bedroom

The quotes are very close in price, but the equipment to be installed is quite different:

1. Installer ONE proposes to install a Tri-Zone 36,000 BTU Hyper Heat compressor with (1) 18,000 BTU indoor unit in basement and (2) 9,000 BTU indoor units in the sunroom and bedroom. All units will be FH-series.

2. Installer TWO proposes to install (1) single-zone 18,000 BTU FH-series indoor/outdoor combo in basement and a Dual-Zone BTU Hyper Heat compressor with (1) 9,000 BTU G-series indoor unit in the bedroom and (1) 15,000 BTU G-series indoor unit in the sunroom.
He said that it's not possible to use a single compressor. He says that FH-series indoor units make noise when connected to a single compressor.

I looked at the specs on the Mitsubishi web site, and the FH-series appears to be slightly better in terms of heating and cooling efficiency. It also seems to have the latest in added technology (the "i-See" scanning of rooms, for example).

I assume that the difference in number of compressors relates to specifics of my house that can't be commented on, but any insight into that difference would be much appreciated. However, I'd like to know whether anyone can confirm the added noisiness of FH-series indoor units when installed together on one compressor. Also, what's the bottom line difference between FH and G? What are the trade-offs?

Thank you so much in advance for any help you can give me. This is an expensive install on an in-law suite, so I'd really like to spend my money wisely.

[kdean1]

The multi-zone Hyper Heat units have a significantly lower heating capacity than the single zone units.
In similar situations we have installed a single zone Hyper Heat system for the first floor and a dual zone system upstairs. This makes full use of the extended heating capacity where it is needed most.

[LeAnn]

I think that makes a lot of sense. Maybe Installer TWO meant that multi-zone Hyper Heat units don't heat as well when he said, "There is no way to connect all 3 to the same outdoor unit." We live in the Northeast where it gets pretty cold sometimes, so this is important to know.

A clarification: the bedroom that I'm planning to heat/cool will be on the same level as the main basement but directly under the sunroom (currently heated with electric baseboard and no A/C).

What about the difference between FH-series and G series indoor units? Installer ONE just told me in a phone call that they have two differences:

1) FH-series has the "iSee" sensor that scans the room for living creatures and programmable, multi-vents
2) FH-series is Hyper Heat

If G-series indoor units aren't Hyper Heat, why would Installer TWO propose to use a Hyper Heat outdoor unit (MXZ-3C24NAHZ2)?

[FlyersFan]

Has either contractor done a load calculation to determine what size equipment you need? Once the system is sized the contractor can build out your system on Mitsubishi's Diamond System Builder (free software) and you'll see what heating and cooling BTU outputs each indoor head will deliver.

If installer 1 is using a 3 ton hyperheat model there will need to be a branch box installed. The FH models do tend to be a bit noisier in heating mode than the GL models are: there can be a fair amount of popping and cracking as the indoor coil warms up in heating mode. The other common noise complaint with the FH units is that the iSee sensor does make noise when it rotates and it may bother someone if it's in a bedroom. You can use the GL model indoor units on any of the hyperheat outdoor units as well and get the same heating performance.

Depending on parts availability in your area installer 2's option gives you the ability to have at least one functioning unit while waiting on parts to fix a down unit.

[LeAnn]

I think that Installer 1 did a load calculation but without considering the sunroom's windows. Does that make sense? He did say that if I wanted to use the Mitsubishi as the primary heat source (instead of in tandem with the electric baseboard) that I should upsize the BTU.

Installer 1 included a branch box in his proposal to work with an MXZ-4C36NAHZ2 outdoor unit.

Thank you for confirming the noisier operation of the FH models. We're not sure whether the iSee sensor is a feature that we care strongly about, so extra noise might be a reason to go with the GL model. Thanks also for confirming that the GL indoor units will heat as well on any hyperheat outdoor unit. That wasn't clear from the Mitsubishi website.

Having one functioning unit while waiting to fix a down unit rates as an important consideration. Thanks for pointing that out.

[Adlerberts-Protege]

I install lots of hyperheat outdoor units with the G series indoors. Customers always love that match.

The times I install the FH indoor units I always get complaints about noise. I installed an FH indoor unit in my own home an it rattles and makes unnecessary noise. I plan on installing a G series when I get around to it.

[LeAnn]

That's very useful information! Thank you very much.

[James Colver]

I'm a Mitsubishi dealer and frankly I don't understand why so many people use their stuff. Frankly there are other manufacturers out there like Media. Their equipment is better in just about every way and the pricing is a lot more reasonable.

[Makeitcold]

Look at the submittal details for each indoor head proposed, the FH series appears to have almost no dehumidification ability until you get up to at least 1 ton. I wish they made a stand-alone GL 6k btu head