| Commercial HVAC Questions and discussions regarding HVAC for commercial buildings |
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12-19-2006, 05:23 PM
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Regular Member
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Join Date: Mar 2004
Location: Vancouver, BC
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Anyone got any comments, good, bad, or indifferent regarding these types of distributed DX systems? Daikon, Mitsubishi, Colt, etc. are flogging these systems as the latest and greatest solution to local zone HVAC control. I have some concerns about a lot of high cost/high pressure refrigerant pipes scattered through a building in terms of risk management. They claim a higher energy efficiency, but I think a good old two-pipe water to air packaged heat pump system wouldn't be that much worse, and you're only going to be dealing with low pressure water if it leaks.
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12-19-2006, 05:36 PM
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Join Date: Dec 2005
Location: Rockhill South Carolina
Posts: 348
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I would rather have a ref leak above ceiling tiles than water.Almost all supermarkets are piped over head,and besides most of the time if the piping in the overhead is tight after startup it is usually trouble free.The key though is a proper startup.
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12-19-2006, 10:26 PM
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Professional Member
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Join Date: Dec 2005
Location: North America
Posts: 137
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We have installed 50 or more and I have started up over a hundred by know. Mitsubushi only. The only problem is no service calls
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12-20-2006, 09:12 AM
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Member- bad email address
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Join Date: Jun 2002
Posts: 48
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These type systems are only new to U.S. Been in Asia and Europe for years. As stated, proper start-up is key.
The few people I know that work on them say service calls
are few and far between. The efficiencies are due to the
variable speed compressors.
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09-24-2008, 09:29 PM
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Join Date: Sep 2008
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This is the latest technology and it is not just a lot of BS. By the way, there are few failures, but you better know your HVAC before you attempt an install or service call.
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09-28-2008, 08:39 AM
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Join Date: Dec 2007
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Do have some training and info before installing.
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09-28-2008, 05:49 PM
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Join Date: Mar 2003
Posts: 4,182
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we have done Daikin systems and find them to be trouble free. The energy recovery stuff is great and allows for even better efficiency while running some zones for heating and some for cooling. One packaged unit cannot give you the flexibility of these systems. They are very common outside the US and work well.
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10-08-2008, 06:54 AM
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Banned
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Join Date: Jun 2008
Location: LONDON
Posts: 57
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Daikin,Mitsubishi
Quote:
Originally Posted by gmcd
Anyone got any comments, good, bad, or indifferent regarding these types of distributed DX systems? Daikon, Mitsubishi, Colt, etc. are flogging these systems as the latest and greatest solution to local zone HVAC control. I have some concerns about a lot of high cost/high pressure refrigerant pipes scattered through a building in terms of risk management. They claim a higher energy efficiency, but I think a good old two-pipe water to air packaged heat pump system wouldn't be that much worse, and you're only going to be dealing with low pressure water if it leaks.
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We are specialized in installation of these systems....and what i gather is that you dont have a clue ..what is happening with these higher pressures maybe that is why you posted so many " smart " words
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10-11-2008, 08:28 AM
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Join Date: Oct 2001
Posts: 5,599
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CB magazine did a full story on this new application in their September issue http://www.contractingbusiness.com/
__________________
"when in doubt...jump it out"
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10-20-2008, 05:55 PM
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Join Date: Sep 2008
Posts: 5
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VRV off the beaten path
I don't know how we got so far off topic, but to get back to VRV technology, the stuff is great. It is not the death of chillers and package systems, only another solution that may provide better control while saving energy. If you look at the full picture, performance, longevity, low-energy consuption, ease of installation, low maintenance cost, self diagnostics, then these systems often out perform all the other technologies.
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11-04-2008, 06:57 PM
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Regular Member
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Join Date: May 2007
Posts: 22
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think of it as chill water
Quote:
Originally Posted by gmcd
Anyone got any comments, good, bad, or indifferent regarding these types of distributed DX systems? Daikon, Mitsubishi, Colt, etc. are flogging these systems as the latest and greatest solution to local zone HVAC control. I have some concerns about a lot of high cost/high pressure refrigerant pipes scattered through a building in terms of risk management. They claim a higher energy efficiency, but I think a good old two-pipe water to air packaged heat pump system wouldn't be that much worse, and you're only going to be dealing with low pressure water if it leaks.
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The concept was born from Daikin in Japan 1982 and was a solution from the chiller group. They figured that they could move refrigerant more efficiently than water or air.
If the piping is done correctly it is a moot point. Just remember about refrigerant density in the space. ASHRAE 15 states R 410A at a max of 25 lbs per 1000 cu ft.
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11-05-2008, 09:11 PM
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Join Date: Sep 2008
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Are you an employee of Daikin?? 
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11-05-2008, 11:27 PM
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Professional Member
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Join Date: Apr 2007
Location: Dallas
Posts: 233
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What happens when a compressor burns out!! I would like to know how you would clean up a system that is so large in piping length.
__________________
"Blessed are the pessimistic, for they hath made backups."
Picture is of Christmas decorations from someone in Grand Rapids Mich. They only had it up for two days-causing too may accidents in the busy street next to the house!
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