VRV/VRF versus Chilled water system 5

[sridhar1312]

Off late I have come across manufacturer after manufacturer coming out with VRV /VRF system and aggressively .It is being marketed for most of the applications.I have found the economics does not work out in favor of the VRV /VRF compared to Chilled water system.

Even in VRV/VRF digital scroll as well as VFD driven compressors are in competition. At least in the INDIAN context where predominantly only cooling is required chilled water systems are economical and reliable.
Can any one throw light and let me know the strengths and limitations of VRV/VRF system especially where only cooling is needed.
Further when we use the VRF/VRV most of the indoor units are standard product having 2 row cooling coils and does not dehumidify to the extent is neeeded for coastal climate like Madras /Bombay

 

[AnotherEllis]

Read through the posts again. Tonnage ranges are discussed.

If you want a scientific LCC for one of these systems (as in you are considering one for a project) I would recommend you do the legwork yourself, and have a 1st person experience relevant to what you are working on. The manufacturer's reps are more than happy to inundate you with product info and selections. No 3rd party LCC is going to be a perfect match for your project.

And there is nothing experimental about VRF. These systems are new only to designers in the US. They have been around for upwards of 20 years in other more flexible markets.

http://www.ellisconsultingengineers.com

 

[tys90]

Some people mention the complexity of VRF systems versus chilled water. Sure it's a complex operation but it's all pre-engineered essentially. The installs I've seen have been dead simple. The design isn't overly complicated either, just different. The proprietary nature of the entire system is a bit worrisome.

And as far as costs go, definitely be careful. The efficiency of scale has a big effect on these systems, each project needs to be evaluated individually to see if it makes sense.

 

[cry22]

Ellis,
What I meant is that statements are made as VRF being cheaper without having performed an LCC.
One cannot take statements as energy efficient without having performed an LCC.

As for experimental: I am sorry to disagree with you but in the US, these systems are installed in a handfull of projects, so to obtain a qualified service technician, good luck.

I can even give you a true case in point from personal experience - I went green and bought a gas-fired tankless water heater for my house (yes, the bills were lower, endless HW, etc), trouble was, when I had to service the darn thing, there was no technician to be found within 100 miles.
So I lost out, I had to revert back to the old storage tank water heater. Even though Tankless water heaters have been a round for decades in Europe.

Just because they have been around in Europe does not mean they are good to begin with, it does not mean they are efficient neither. It just means that Europe has its way and the US has its own way of doing things.

One last thing, we are trying to help each other on this forum, let's refrain from being agressive from each other.

 

[AnotherEllis]

Sorry you took my post as aggressive. It's not the intent.

In the 1st few VRF projects I did, factory training for the mechanical contractor and the end user was part of the spec. I also required an extra condensing unit of each tonnage to be delivered and kept stored on site for spare parts availability (having an entire assembly means no matter what component goes bad, you will have one available.)

It worked out well, and the installed cost of the VRF still came in under the 1st cost of the chilled H2O.

I am in a heavily populated area, and at this juncture there area host of qualified technicians who can work on the VRF systems. Quite frankly, aside from some circuit boards, they are pretty simple systems.

http://www.ellisconsultingengineers.com