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# Power Consumption of Chiller

## Power Consumption of Chiller

#1
04-15-09, 08:03 AM
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Join Date: Apr 2009
Posts: 5
Power Consumption of Chiller

Dear all,

I am a student. I am dealing with a academic research about power consumption estimation of a industrial used chiller, specially for HVAC of a building. I have done some mathematics model to estimate the power consumption based on some know factors (ex: chiller supply,return temperature, condenser flow rate etc). I am wondering what i can do after i can predict the power consumption in a particular situation. How to optimize the power usage of the chiller. Can you guys give me some advice. Thank You.

#2
04-16-09, 06:26 PM
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Join Date: Oct 2002
Location: Troy, VA
Posts: 1,392
optimize the power usage of the chiller?

While this is a Homeowner geared site, I'll attempt to give you an answer because I understand what you are asking.

Depending on the size of the chiller you will have many steps of loading and unloading. Power consumption will be dependent on the % of load on the chiller.

Amps times Volts = Watts.

If your set point is 45 degrees and the water temp is 60 the chiller should be fully loaded. Max watts or power consumption. But as the water temp drops the chiller will unload in steps and therefore reduce power consumption.

The manufacturer should have this data available, watts per stage of load. Or you could rune the chiller manual in different stages and take your own readings.

I would plan for the max consumption and use the less load consumption as a "gimme".

Don't forget setback control, which should be in the electronics, a chiller is normally designed for a 10 degree delta T. If sized correctly the chiller will have no problem handling the load.

#3
04-17-09, 07:10 AM
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Join Date: Apr 2009
Posts: 5
While this is a Homeowner geared site, I'll attempt to give you an answer because I understand what you are asking.

Depending on the size of the chiller you will have many steps of loading and unloading. Power consumption will be dependent on the % of load on the chiller.

Amps times Volts = Watts.

If your set point is 45 degrees and the water temp is 60 the chiller should be fully loaded. Max watts or power consumption. But as the water temp drops the chiller will unload in steps and therefore reduce power consumption.

The manufacturer should have this data available, watts per stage of load. Or you could rune the chiller manual in different stages and take your own readings.

I would plan for the max consumption and use the less load consumption as a "gimme".

Don't forget setback control, which should be in the electronics, a chiller is normally designed for a 10 degree delta T. If sized correctly the chiller will have no problem handling the load.

Of course the power consumption will be lower as the temp is lower. But for a HVAC system of a building. What can i do or how to reduce the power consumption?

#4
04-17-09, 04:01 PM
Member
Join Date: Oct 2002
Location: Troy, VA
Posts: 1,392

What is the Make, Model and Serial of the chiller?

What does the chiller serve? Do you have VAV boxes? Or Fan Coil units?

What controls the building? Johnson controls, Trane Varitrac or Tracer?

#5
04-17-09, 05:36 PM
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Join Date: May 2007
Location: Wisconsin
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Dear all,

I am a student. I am dealing with a academic research about power consumption estimation of a industrial used chiller, specially for HVAC of a building. I have done some mathematics model to estimate the power consumption based on some know factors (ex: chiller supply,return temperature, condenser flow rate etc). I am wondering what i can do after i can predict the power consumption in a particular situation. How to optimize the power usage of the chiller. Can you guys give me some advice. Thank You.
A classic ASHRAE magazine question! Are you familiar with that engineering magazine?

#6
04-17-09, 06:20 PM
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Join Date: Oct 2002
Location: Troy, VA
Posts: 1,392
Excellent

EC, glad you stopped by! Had thought of sending an invite to join the discussion.

Now that I reread the original post. Adrian, are you talking about an existing building or a hypothetical in the class room?

Basically, we know that the chiller will use less power when the load is low. But the load is the building.

So in the real world the chiller is going to make what ever temp water you want.

But if the building is not properly controlled you maybe putting a load on the chiller when it is not necessary.

In the real world there can be several different scenarios you could use here which would effect the chillers operation and of course power consumption.

So, the question is this a real world situation or are you doing this in class as an exercise?

Last edited by Jarredsdad; 04-17-09 at 06:45 PM.
#7
04-18-09, 01:58 PM
Banned. Rule And/Or Policy Violation
Join Date: May 2007
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EC, glad you stopped by! Had thought of sending an invite to join the discussion.
Well -you know me -I'm roaming all over this board.

That magazine(I have some at home) has had articles where submissions are made by Ph.D's, corporations and universities soliciting others to help solve vexxing HVAC issues. Some are fun to simply read the title description of. They rank up there with rocket science.

Adrian's question would be one for that magazine - and probably already researched and papers done on it! if not, plenty of people to contact could be found in that magazine.

#8
04-18-09, 11:05 PM
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Join Date: Apr 2009
Posts: 5

What is the Make, Model and Serial of the chiller?

What does the chiller serve? Do you have VAV boxes? Or Fan Coil units?

What controls the building? Johnson controls, Trane Varitrac or Tracer?

I am noting doing a power optimization of a built building. So i don't have the information. I am doing a research that what i can do to improve the power consumption of a chiller if i know what the power will be at a particular condition. Actually i am doing it somehow related to Johnson controls.

#9
04-18-09, 11:10 PM
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Join Date: Apr 2009
Posts: 5
Originally Posted by ecman51`
A classic ASHRAE magazine question! Are you familiar with that engineering magazine?
NO. I didn't. Of course i want it if you would like to give me some related information in the web.

#10
04-18-09, 11:15 PM
Member
Join Date: Apr 2009
Posts: 5
EC, glad you stopped by! Had thought of sending an invite to join the discussion.

Now that I reread the original post. Adrian, are you talking about an existing building or a hypothetical in the class room?

Basically, we know that the chiller will use less power when the load is low. But the load is the building.

So in the real world the chiller is going to make what ever temp water you want.

But if the building is not properly controlled you maybe putting a load on the chiller when it is not necessary.

In the real world there can be several different scenarios you could use here which would effect the chillers operation and of course power consumption.

So, the question is this a real world situation or are you doing this in class as an exercise?

Actually, i am doing a final year project and real world situation may be suitable.