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| chiller guy
 |  "Re(1):Question on Chilled Water A/C"
, posted Fri 28 Dec 17:05  
Peter,
Now that have supplied a model # it appears you have a 30 ton liebert computer room unit (air handler) that needs a chilled water supply. From you discription of the previous installation I would guess the chilled water to these units was supplied from a building chilled water loop which in turn used large chillers to supply everything. You will need a 30 ton chiller (and pump) to operate the units at design conditions. Also check the operating voltages of the units to insure you have the power available to operate them (230v vs 460v)
All refrigerants are safe - All refrigerant are dangerous. The difference is YOU !!!
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| harpo
| "Re(1):Question on Chilled Water A/C" , posted Thu 27 Dec 19:35
if the unit is 30 tons you probably have 2 compressors,and the unit is what we would consider self-contained chiller.to give you a comparison...just think of a water fountain in an office hall way or school.it has a small compressor within and chills the water as people drink ...and the water drains away.the chiler you have doesn't DRAIN it recirculates in a SEALED WATER SYSTEM and chills it over and over again.Yes 30 tons might be to much for now but that can be isolated down to say15 tons within the chiller itself.like staed you need to install a pump(moves the chilled water around) and an air handler to circulate the computer room air to cool the load off the servers.related controls for the air handler would maintain a discharge air temperature into the roomas the room cools the controller would shut(modulate) the chilled water and with that the chiller would cycle off...until the room temp rises above control point in he air handler.so your concern is chilled water piping,air handler placement and controls, chilled water pump.how to get the air to the servers.... ductwork over the towers with registers OR raise the floor12" or more and blow the air into the false floor space then cut openings the size of the tower frames and locate them over the holes.seen ansd serviced both types of computer rooms for MCI.VERIZON...doing it with a raised floor makes for a clean an organized room with the air coming up and all the wires going down.the return air coming up thru te towers will be plenty to cool the over all space.model and brand of chiller for more info on it's operation if your interested...will check back...
It ain't going to get any lighter looking at it!
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| | pbrunnen
| "Re(2):Question on Chilled Water A/C" , posted Fri 28 Dec 15:29
harpo,
Thanks for your response!
Basically I have been given two of these Liebert System3 air handlers with the environmental control systems and infrared humidifier (model: FH529C-A03). I only need to get one running and keep the other for spare/parts. They are both in great condition from what I can see. The computer responds with the proper errors and passing self-tests, the bearing on the blower is good. I can't power up the blower motor to test that. No rust or corrosion outside of the humidifier tray where the fresh water sat.
They both have 1 inch lines marked chilled water and return.
I don't know about the compressors. As far as building manager knows it was part of the building wide sealed water system. The building system was huge (based on markings that I find there were 8 large 4ft x 6ft x 15ft compressors). I will look around again, but I don't remember seeing any dedicated compressors.
The units were installed somewhere from the '91-'95 time frame.
Also, thanks for the suggestions on the flooring. I am using 1ft. raised flooring for the cold air and (at least for now) a large ceiling duct for hot air return. I am planning on the hot/cold isle setup. The current space is 400 sq. feet with the option to expand out to 800. I planned on keeping the unit in the back right corner which would become the back middle if I expand.
Thanks again! -Cheers, Peter.
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| chiller guy
| "Re(1):Question on Chilled Water A/C" , posted Tue 18 Dec 19:40
Probably the answer to your question depends on how much trouble you want to go to and how much money you have to spend.If what you have is a chiller package it already has some refrigerant (Freon) in it to cool the water. Changing it to an all refrigerant system would be real ugly.
You could use other heat transfer fluids in the unit but that won't be pretty either. Why would you want to? Water is the best heat transfer fluid (and refrigerant)so why mess with perfection?
You can certainly build a chilled water system but have you any idea how? What size pump will you use (hp & GPM)? What size water lines will you use? What will you use for cooling coils and where will you put them? Any control valves involved? Pneumatic or electric? How will you control the system? The list go's on and on.
Sometimes free or cheap things are neither. Good Luck
All refrigerants are safe - All refrigerant are dangerous. The difference is YOU !!!
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| | harpo
| "Re(3):Question on Chilled Water A/C" , posted Fri 28 Dec 17:38:
OK now were both lookin at the correct end of the cow to say it politely.you have a chilled water liebert air handler that is off a house chiller system with the cooling supplied from larger tonnage chillers for the whole building.that number is X1000 for the BTU rating and divide that by 12,000 BTUs (equals 1 TON) for the tonnage availible power to supply is 460/3 phase check the contactor section on the left when you swing up the cover for reheat contactors...each one is a stage if they are there..might need a fire shutdown jump for the fan to run if your testing the fans.you need a chiller to supply cooling water to those AHUs and they are down flow types with all the setpoints within to run a space...with that false floor.your decision is to predict how large the load is going to be in the now/ future and install both AHUs pipes and all..then what tonnage chiller outside the building???...according to the total on both you can supply 88 tons of cooling into the room it may not be that now but it could end up coming close.if your in a winter climate a dry cooler in series with the return line out to the chiller will give you free cooling with the low ambients of the season and keep the chiller off till spring.the chiller will be self contained just like the liebert is and the only connections would be the water piping between each .the size and brand along with a pump is the next step.i would consider installing both lieberts and valve off the one not in use till the space grows. you dont need return ducting to the AHU it should be open to the space so when you step up and look down into the unit your viewing the filters and those probes on the right are the control sensors for temp and RH
It ain't going to get any lighter looking at it!
[this message was edited by harpo on Fri 28 Dec 17:45] |
| | chiller guy
| "Re(3):Question on Chilled Water A/C" , posted Wed 19 Dec 19:11
Peter,
Getting a pro. involved is a great idea. If you have an operating chiller then you need an air handler/computer roomn unit to handle the load using chilled water.
If the refrigerant is in the water you have a big problem (leak). A chiller is designed to use refrigerant to cool the water (secondary refrigerant) which in turn cools the space. So your computer room unit will be using chilled water to cool the space/equipment.
All refrigerants are safe - All refrigerant are dangerous. The difference is YOU !!!
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| | harpo
| "Re(4):Question on Chilled Water A/C" , posted Sat 29 Dec 10:10
go over an GOOGLE images and put in (air cooled chillers) and you will access pix and info on chilled water setups
It ain't going to get any lighter looking at it!
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