Actually had a question for any of our european HVAC engineers if we have any, regarding variable flow refrigerant systems that are very common in Europe.
Anyone involved with the industry?
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Engineers involved with air conditioning?
pseudorealityx
Member Since: January 31, 2010
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Posted: Friday, May 06, 2011 - 03:59 AM UTC
Krieg-Hammer
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Posted: Wednesday, June 08, 2011 - 09:31 AM UTC
Quoted Text
Actually had a question for any of our european HVAC engineers if we have any, regarding variable flow refrigerant systems that are very common in Europe.
Anyone involved with the industry?
For me HVAC means High Voltage Alternating Current..... If it were that I'd help
okdoky
Member Since: April 30, 2007
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Posted: Wednesday, June 08, 2011 - 10:43 AM UTC
Hi there mate
I work in the construction industry if it is to do with building heating, cooling and air conditioning. What is the question you have and I might be able to ask around the office if it is not too technical?
If it is vehicles ,,,,,,, your screwed chum ,,,,,,,,,,,,, not a clue !!!!!
Nige
I work in the construction industry if it is to do with building heating, cooling and air conditioning. What is the question you have and I might be able to ask around the office if it is not too technical?
If it is vehicles ,,,,,,, your screwed chum ,,,,,,,,,,,,, not a clue !!!!!
Nige
pseudorealityx
Member Since: January 31, 2010
entire network: 2,191 Posts
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Posted: Wednesday, June 08, 2011 - 11:00 AM UTC
Quoted Text
Hi there mate
I work in the construction industry if it is to do with building heating, cooling and air conditioning. What is the question you have and I might be able to ask around the office if it is not too technical?
If it is vehicles ,,,,,,, your screwed chum ,,,,,,,,,,,,, not a clue !!!!!
Nige
Construction industry is probably just as good (possibly better) in this case....
My question concerns systems like the Mitsubishi City-Multi type systems. Variable flow refrigerant systems. How prevalent are refrigerant line leaks? How do you trace them through buildings? What are some of the common issues you've seen with these systems?
They aren't that popular on this side of the pond yet, but I know Europe and Asia have been using them a lot longer than us. It would be interesting to get an opinion from your side instead of just the sales guys talking to us.
Thanks!
c5flies
Member Since: October 21, 2007
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Posted: Wednesday, June 08, 2011 - 11:54 AM UTC
Hi Jesse,
Not an engineer, nor from Europe, but I'll put my 2 cents in. I'm not all that familiar with these systems, other than somebody is trying to get them Stateside. Honestly, I don't see any real benefit and would rather have an office building with a VAV pneumatic or DDC control system.
Refrigerant lines do leak, on the whole rarely, but you will have leaks, usually at the source of brazing. Also, TI work may puncture one in the future, or crush/kink a line rendering it useless. Will they be accessible after building construction and the tenants move in? I find it much easier to repair a low voltage line, or run a new one, than repairing/replacing a copper line. The future will bring non-copper linesets which might solve some of these issues, but I still don't see the benefit in these VFR systems.
Another consideration is how well they will be installed, such as brazed correctly, evacuated and charged. If not done correctly they may work fine for a while but down the road problems will arise. The future will bring non-copper linesets which might solve some of these issues, but I still don't see the benefit in these VFR systems.
Ductless splits are popular in Europe and Asia also, but sorry, I find these to be pure rubbish and over priced. Yeah, I know, old dog, new tricks....
Not an engineer, nor from Europe, but I'll put my 2 cents in. I'm not all that familiar with these systems, other than somebody is trying to get them Stateside. Honestly, I don't see any real benefit and would rather have an office building with a VAV pneumatic or DDC control system.
Refrigerant lines do leak, on the whole rarely, but you will have leaks, usually at the source of brazing. Also, TI work may puncture one in the future, or crush/kink a line rendering it useless. Will they be accessible after building construction and the tenants move in? I find it much easier to repair a low voltage line, or run a new one, than repairing/replacing a copper line. The future will bring non-copper linesets which might solve some of these issues, but I still don't see the benefit in these VFR systems.
Another consideration is how well they will be installed, such as brazed correctly, evacuated and charged. If not done correctly they may work fine for a while but down the road problems will arise. The future will bring non-copper linesets which might solve some of these issues, but I still don't see the benefit in these VFR systems.
Ductless splits are popular in Europe and Asia also, but sorry, I find these to be pure rubbish and over priced. Yeah, I know, old dog, new tricks....
pseudorealityx
Member Since: January 31, 2010
entire network: 2,191 Posts
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Posted: Wednesday, June 08, 2011 - 12:13 PM UTC
Quoted Text
Hi Jesse,
Not an engineer, nor from Europe, but I'll put my 2 cents in. I'm not all that familiar with these systems, other than somebody is trying to get them Stateside. Honestly, I don't see any real benefit and would rather have an office building with a VAV pneumatic or DDC control system.
I don't know why anyone would WANT pneumatic today. DDC controls with a modern VAV system? Sure.
Quoted Text
Refrigerant lines do leak, on the whole rarely, but you will have leaks, usually at the source of brazing. Also, TI work may puncture one in the future, or crush/kink a line rendering it useless. Will they be accessible after building construction and the tenants move in? I find it much easier to repair a low voltage line, or run a new one, than repairing/replacing a copper line. The future will bring non-copper linesets which might solve some of these issues, but I still don't see the benefit in these VFR systems.
I know some of the benefits...
Big efficiency increases over other DX type systems. Because it works a lot like a water source heat pump system, except using a refrigeration cycle instead of a heat exchanger/cooling tower setup. And the smart distribution block is a great package. Redirects refrigerant depending on temp to the units that need it. The units in cooling in central parts of your building are offsetting the units in the exterior parts of your building that are in heating (depends obviously on climate zones). We've also seen sizable reductions in the size of the main building electrical service coming in.
No need for large mechanical rooms for boilers, plate and frame heat exchangers, pumps, etc. No more condenser water lines.
The air handling units themselves are much smaller, and come in lots of variates.
Biggest straight performance fault I have with them is they don't do a great job with high latent loads (humidity).
Quoted Text
Another consideration is how well they will be installed, such as brazed correctly, evacuated and charged. If not done correctly they may work fine for a while but down the road problems will arise. The future will bring non-copper linesets which might solve some of these issues, but I still don't see the benefit in these VFR systems.
Agreed. We've designed 2 of these jobs so far, and both have been priced out ridiculously because contractors have very little familiarity with the systems. That said, at least with the Mitsubishi stuff, they require a licensed (by Mitsu) contractor to install the equipment to get their warranty. All refrigerant lines leak over time. How do you trace a building full of refrigerant lines going to 40 or 50 or more units? Sounds like a nightmare.
Quoted Text
Ductless splits are popular in Europe and Asia also, but sorry, I find these to be pure rubbish and over priced. Yeah, I know, old dog, new tricks....
Ductless splits can be great solutions to certain situations. We use them all the time in small equipment rooms, be it elevator machinery, vacuum pump rooms for doctor's offices, A/V equipment, small computer/data rooms, etc.
Sorry if I went off there....
c5flies
Member Since: October 21, 2007
entire network: 3,684 Posts
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Posted: Wednesday, June 08, 2011 - 01:13 PM UTC
Yes, tracing out the ref. lines could be a nightmare...but if it's replacing a chiller or a choice between, what would be worse? I'd probably rather have a ref. leak than a water leak. Although, with our older chiller systems, water leaks in the lines seem to be almost non-existent, and it probably would be the same with the ref lines if installed properly. But I was thinking more on the lines of these systems being used in smaller office settings-non chiller (40-50 units as you said).
I only mentioned pneumatic systems since there are still a few around that I work on, so age is a testament to these and I know what repairing them involves.
As I said, I am pretty much unfamiliar with these systems...and hope to be retired before I need to deal with them Factory certified is great, but as they increase in popularity I'm sure the quality of the installers will go down, and the all important low bid will win. That can happen (and does often) with the equipment in use here now, the difference is that there are plenty of techs to put it right. And that is what worries me more than the equipment. If the industry changes and requires more training, fine. Right now, if a chiller goes down you'll find someone to get it back up and running, if one of these fail...? Like I said...I'm an old dog. I realize things need to change (and sometimes for the better) but that doesn't mean I'm going to like it!
And yes, we use ductless splits too...but if I can find any other solution I'll use it over them.
I only mentioned pneumatic systems since there are still a few around that I work on, so age is a testament to these and I know what repairing them involves.
As I said, I am pretty much unfamiliar with these systems...and hope to be retired before I need to deal with them
Factory certified is great, but as they increase in popularity I'm sure the quality of the installers will go down, and the all important low bid will win. That can happen (and does often) with the equipment in use here now, the difference is that there are plenty of techs to put it right. And that is what worries me more than the equipment. If the industry changes and requires more training, fine. Right now, if a chiller goes down you'll find someone to get it back up and running, if one of these fail...? Like I said...I'm an old dog. I realize things need to change (and sometimes for the better) but that doesn't mean I'm going to like it! And yes, we use ductless splits too...but if I can find any other solution I'll use it over them.
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