Replywhat type of compressors do you want.....scrolls or screws?
Regular Guest
For the residential towers,providing Vfd air cooled chiller is beneficial in terms of energy savings ? As I discussed with multiple suppliers all have different opinion about this. York is telling as compared to constant speed chiller VSD chiller will give 20 to 25% energy savings . But Trane is telling that they have already more compressors comparing to york and the energy consuming will same as VSD air cooled chiller. Only advantage they are telling that starting current can make zero. I also heard that for the VSD chillers wear and tear for the compressors will be more because of running in high rpm.
Can you suggest which type of air cooled chiller will be more energy efficient for commercial towers.
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what type of compressors do you want.....scrolls or screws?
Professional Member*
If cost of kW demand is an issue, the VFD's might be ahead in this horse race.
A dying culture invariably exhibits personal rudeness. Bad manners. Lack of consideration for others in minor matters. A loss of politeness, of gentle manners, is more significant than is a riot.
― Robert A. Heinlein
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Screw chillersOriginally Posted by 71CHOPS
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Professional Member
we have number of york vsd(YCIV) chillers. after the 10 year operation, almost all compressors were overhauled. so there is a fact that the high RPM may shorten the life. i don't feel these chillers made significant energy saver by vfd compressor compare to fixd speed.
Professional Member*
I have a feeling the failures you experienced, were also due to the high ambient conditions in your area.
Wether they have a VFD, or are Wye/delta start, they are still gonna be spinning the same RPM.
The claimed savings with a speed drive is associated with being able to match the compressor capacity to the actual load. If the units are design to closely match the load, and you dont have large variations, a speed drive isnt going to save much. If you have wide load swings, you will save.
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Except that some OEMs "overspin" their compressors with the VFD.
I know you already know this.
In honor of RichardL: "Ain't 'None' of us as smart as 'All' of us".
Professional Member
screw chiller slide valve will varies the load until 10% capacity. then where is the significant saving when using the vfd compressor
Professional Member
10% capacity on a fixed speed compressor uses significantly more energy than a VFD compressor at 10% capacity.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
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Moideen, what are the run hours on your compressors ? 10 years doesn't seem too bad but what parts and why were they overhauled ?
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In market commonly saying that york vfd compressors getting damage in lesser years. The reason behind saying that they are varying rpm high as 7000 rpm. I think for the chiller age will be more than 15 years. So for 10 year compresser getting damage what is the use behind using vfd chiller . Energy saving will indirectly effecting the life cycle .
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Professional Member
A large multitude of factors can damage a chiller long before an arbitrary date. Many of those items have nothing to do with whether the compressor is VFD driven or constant speed.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
Professional Member
So do you have soft stop enabled ?
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Today an authorized trane’s service person came to my office and introduced a new product for the screw chiller. A vfd package for trane RTAC screw chiller. RTAC already has slide valve mechanism. I asked, how a vfd operate with slide valve as reducing the load. Then he replied that their advanced processor will do that work. They showed some presentation, but failed to convince the theory behind the logic. truly, I feel a mere dogma to make money.
Professional Member
soft starting of compressor
Keep it simple to keep it cool!
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