PDA

View Full Version : Misubishi 8 zone City -Multi.


Green Mountain
10-31-2011, 09:31 PM
This is the Branch Control box that I piped up for this new City Multi system. It is in an upper end apartment building.

The system reminds me of a supermarket rack system.

https://lh3.googleusercontent.com/-hM91_E1hsrQ/Tq9IylhJKDI/AAAAAAAAH6s/GfHteyD9r2g/s258/7%252520north%2525201.jpg

These are the line sets for 4 of the apartments runing down the hall. Both lines need to be insulated.

https://lh6.googleusercontent.com/-5_xz7EP0Hhg/Tq9I3AvmgfI/AAAAAAAAH6w/yH-C2EUby7E/s258/7%252520north%2525202.jpg
SkyHeating
11-01-2011, 03:54 PM
Pics are a bit hard to see but I would like to see more, what indoor units are attached to the outdoor? What outdoor unit did you use?
Gunslinger
11-01-2011, 07:32 PM
Is this the system that allows a zone to heat and another to cool at the same time? If so, how does it work? Please don't say "very well":grin2:
SkyHeating
11-01-2011, 08:19 PM
Is this the system that allows a zone to heat and another to cool at the same time? If so, how does it work? Please don't say "very well":grin2:

My company has installed these and yes they can do it... "very well" simply put the outdoor unit runs in either heating or cooling depending on largest load. Then takes the smaller load and puts it into and removes it from those places..

Example 30kheat load and 10k cooling load. System runs with 20k heat load and uses refrigerant to remove 10k cooling load and adds to heating capacity.
Green Mountain
11-02-2011, 05:53 AM
Sorry for the quality of the pictures. I'll take my real camera down to the job and get some better ones.

We are scheduled to have the factory start up of this system on the 8th of Nov. Hopefully it will work "very well" .

Our saleman called in Mitsubshi to help engineer this job. I am the foreman on the project. Since I am "old school" I am thinking the air handlers are 1200 cfm capacity which are enorous for these apartments. But I'm told that everything is varible and they are needed to be that size for the heating capacity. Hmmm.... details at 11.
Bobscatz907
11-07-2011, 09:32 PM
benncool,
Please keep us posted! I was reccently in NY for a Trade show and spent alot of time discussing and learning from the Factory rep.
Kaedos
11-08-2011, 04:53 PM
1200 cfm? I thought most of the evaporator (whether they be wall hung, or drop ceiling or what have you) were all around 300 cfm? I am mostly likely wrong that number just sticks out in my head. And now that I get off my butt to check my book, the highest CFM 848, with most of the evaporators running around 300-400 cfm. And I am looking at the M & P series book, I think that includes the city splits.
selfemployed
11-14-2011, 10:26 PM
Looks like an old school refrig. guy had something to do with that piping. Nice work there. :D
Green Mountain
11-15-2011, 09:31 AM
Looks like an old school refrig. guy had something to do with that piping. Nice work there. :D

Yeah Scott, it was fun to pipe. The system reminds me of a supermarket rack.
Green Mountain
11-15-2011, 09:36 AM
1200 cfm? I thought most of the evaporator (whether they be wall hung, or drop ceiling or what have you) were all around 300 cfm? I am mostly likely wrong that number just sticks out in my head. And now that I get off my butt to check my book, the highest CFM 848, with most of the evaporators running around 300-400 cfm. And I am looking at the M & P series book, I think that includes the city splits.

Yes these were ducted air handlers. 1200 cfm each. The Mitsubishi engineer said that they were needed to be that big to get the right efficencies during the heating.

We started the system last week. Took 62 lbs of 410A. I am impressed with the system. This is the second one we did in this building. The owner loves the system also. We will have a total of five systems when the building is complete.
fastfreddie
11-28-2011, 01:04 PM
The outdoor unit runs in cooling mode no heat pump!! does not reverse flow it all happens in the magic BC box!!
Tempted
12-08-2011, 08:20 AM
Nice Job cool. My first city multi is in an apartment complex also. 4-WR-2 GSHP units with 32 air handlers. Yours must have huge apartments we used 26 1 ton PVFY's in the units.
It was my first gshp and city multi job. Talk about a learning curve. It was engineered with daily change orders. We're suppose to do 4 more complexes. Bonneville Power out here in Oregon is modeling their incentive program for VRF systems after it.
I've only had minor issues with them so far, mainly HP related. Besides condensate pump connections.