VRF Systems - Would you recommend one?

[hcong]

We have a project here that is a potential for those City Multi-split systems. We looked at both Daikin and Mitsubishi options (24 tons). I know these systems have been around for 20-30 years in other countries, but since they only been in the US for like the last 5 years we haven't gotten much usage information on them. So I thought I would ask for your guy's opinions on the matter.

Questions:
1. Are they reliable?
2. Is there really an energy savings (big enough to outset the upfront cost)? ROI?

Summary of building... two story, 12 zones (design requirement), with existing (2) 25 ton heat pump package units on the roof. Other options include WSHP and VAV system with reheat.

[valdelocc]

We have a project here that is a potential for those City Multi-split systems.

Questions:
1. Are they reliable?

They are reliable when new but with time all sort of problems arrive. No every contractor knows how to work on them units, finding qualify service and repair could be a challenge after the warranty expires and parts are very expensive

2. Is there really an energy savings (big enough to outset the upfront cost)? ROI?

Dont count on substantial energy savings compared to a traditional system.


I would stay away from Mitsubishi but that's just my opinion

I would stay with package units

[hcong]

I would stay with package units

Why is that?

[davo]

We have been installing and servicing Daikin VRV systems for about 8 years.

We have found them highly reliable. Our customers aree reposting 75%-80% reduction in energy usage.

We have repaired a 3 story bank/office building that was engineered wrong and installed even worse. Neither the engineer or installer had speced or installed a Daikin before.

After 6 months and $$$$$$ to make things right, the owner is now so happy with the performance, he specified them for their newest building.

I would recommend choosing a very qualified installer because you will want to maintain a relationship for maintenance and service.

Also, we are showing ways that they can ofFset the cost of the VRV systems by lower constructon costs. Smaller electrical services, lower building heights, smaller generators, smaller switch gears.

[mikeacman]

+1 on being educated on the system your installing .

We have installed both mitsu and daiken .

Prior to both we were educated by the manufactur and had their rep,another local contractor, perform the startup and check out .

I never ran a warranty call because of equipment failures. I did run some because of installation issues. The issues where ,,,,we used a sensor in the return as a room sensor as we were choosing setpoints at a remote location. The sensor was downstream of the outside air tap so we were actually measuring mixed air ....

That is not an equipment problem .


Installation is key in these systems . It must be done by the book.

[technic76]

Ive installed one Daikin VRV and have been to city multi class in NC Im sold on them so far. The Technolgy is unreal and so far the system has had no problems after int. startup.

[Chuck]

Company I work for put a city multi in 9 years ago. It was actually only the second city multi in the US. We put in several more this year.

Onw major problem so far was on the 9 year old system, compressor locked up. These things literally never shut off, just ramp up and down according to demand.

They also have had a couple direct lightning strikes which took out several boards each time. The building is on a hill, a lightning magnet.

The building owner liked it so well, a major addition also got City Multi, he didn't even price anything else.

This is definitely the future of HVAC, like it or not. Simultaneous heat and cool with a 2 pipe Refrigerant system has a ton of advantages over rooftop units or chiller/boiler systems.

[ryan1088]

We have 8 systems in I believe and haven't had a problem yet. The oldest system is only 2 years old though. Agreed with everyone that you HAVE to know what you're doing when you install it.

Side note: we have 7 daikin and one Mitsu systems that do the entire heating and cooling for building. Biggest ones are approximately 30-35 tons.

Really amazing technology! B

[hcong]

Yeah, we just met with the building owner and one of them is German (Europe had these for a while) and it is pretty much a done deal. I made some phone calls and only negatives on heard was that the condensate pumps in the fan coil go out but nothing bad about the outdoor units.

This will be our first time we ever design a system like this; so we will see how it goes. Boss took a Mitsubishi class and we are using the sales engineer like no other.

Thanks for all your inputs.

[Chuck]

Yeah, we just met with the building owner and one of them is German (Europe had these for a while) and it is pretty much a done deal. I made some phone calls and only negatives on heard was that the condensate pumps in the fan coil go out but nothing bad about the outdoor units.

This will be our first time we ever design a system like this; so we will see how it goes. Boss took a Mitsubishi class and we are using the sales engineer like no other.

Thanks for all your inputs.

Very important to follow their pressure test and evacuation procedures and document it. They will ask for it on the final commissioning report.

Are you using the R2 series?

[hcong]

We are using Daikin REYQ240PBTJ with 12 zones of mixed FXMQ & FXZQ. We have 12 branch selectors, and 12 nav. controllers. We have a MUA, exhaust fan, and Daikin VAMs for the OA requirements.

We aren't the contractors, so we just need to make sure the 3-pipe and 2-pipe BS are not too long. The building is only 2 stories so we don't have to worry about vertical max length as much. Condensate lines will be a pain...

[Cold shot]

Our company learned this the hard way too......MITSUBISHI'S ARE THE ONLY MINI SPLIT & VRF'S WE INSTALL NOW! CITY MUTI IS A GREAT PRODUCT.

[fredbear]

i agree

[Cold shot]

I have installed, started & commissioned Mitsubishi Citi-Multi Systems that have been in operation for 10 years. I can not speak to the reliability of other VRF systems. In my opinion, Mitsubishi products are very reliable if installed properly.

[fredbear]

Go with Mitsubishi, it may cost more for equipment but it will save a lot of heartache on installs

[TigerWedgey]

We are looking at a very large scale installation of water cooled VRF application. Nobody has discussed LG as a VRF manufacturer, any thoughts on this companies products and ease of installation?

[fredbear]

lg seems to be ok on small applications, not sure on large scale, does the job spec lg and any other manufacturers? it sounds like a adventure and i love those

[Old Soul]

I would recommend Mitsibushi. I like the way they handle the take off to the individual air handlers better. Contact a local rep and ask for a site tour. Ronald McDonald House in Winston has this setup and they are very happy with it. Installation is everything with these systems.

[fredbear]

mitsis rock....top of the line, cream of the crop

[TigerWedgey]

If you have a scenario where there are many indoor heads, the Mitsubishi has the toughest challenge because two pipes need to run to each one. The more pipe joints, the more potential for a leaks in the pipes.

In a retrofit application, having many sets of two pipes running in the same direction may cause a physical space problem, as opposed to the two or three pipe designs Daiken and LG have.