need a valid explanation

[giovanni]

1st Thanks for all the help in the past. You guys here have been very helpful.

I would like to know if there is such a thing as a dedicated chiller strictly to make ice for a rink ?

The company that is going to build the new rink for us is stating that a screw compressor chiller is not for rinks and that we should be using reciprocating compressors as part of the chiller.

In addition he is stating that .. a 240 ton screw chiller from Carrier ( which we are probably going to purchase) is only for air conditioning and we will only get 120 tons out of a 240 ton unit because they only make air conditioners. "ANY TRUTH TO THE PREVIOUS STATEMENT ?........ We are currently using a rental chiller with 2 screws ( a 200 ton Trane Unit) and is doing fine.
Understand that this company wants to also sell us a chiller in addition to building the rink.

Is there any validity to the above?

[The MG Pony]

That doesn't make sense, some thing is sounding off keel but I do not have the experiance to say what.

[giovanni]

Thats what I sort of figured so I thought I would ask the experts. Thanks MG

[Andy]

1st Thanks for all the help in the past. You guys here have been very helpful.

I would like to know if there is such a thing as a dedicated chiller strictly to make ice for a rink ?

The company that is going to build the new rink for us is stating that a screw compressor chiller is not for rinks and that we should be using reciprocating compressors as part of the chiller.

In addition he is stating that .. a 240 ton screw chiller from Carrier ( which we are probably going to purchase) is only for air conditioning and we will only get 120 tons out of a 240 ton unit because they only make air conditioners. "ANY TRUTH TO THE PREVIOUS STATEMENT ?........ We are currently using a rental chiller with 2 screws ( a 200 ton Trane Unit) and is doing fine.
Understand that this company wants to also sell us a chiller in addition to building the rink.

Is there any validity to the above?

there is some truth in amid the sales patter. What you are after is a glycol chiller not a water chiller, the derating talked about is simply the duty given at the lower fluid outlet temperature.
The company I worked for did build some screw rink packs, but you would need a minimum of 4 compressors (screws can be unloaded but are better switched off for effeciency). Recips are traditionally used on rinks for part load effeciency and close control.
Screws could be used, they will require less maintenance, but in my experience the following works well.

3 recips (possibly a spare #4) flooded ammonia chiller and a water cooled condenser with a cooling tower. You can then add a bit of heat recovery for the snow pit and some hot water. Also a water softener plant for your ice water would be a necessity.

If you are looking for a good job I would talk to Cimco/Lewis, they did an ice rink in Belfast and it never looked back:)

Kind Regards Andy:)

[NoNickName]

A screw compressor chiller with any refrigerant is ok, afterall the glycol temp is not very low.
If you are interested into an independent company offer, please feel free to contact me off list. Sorry for the shameless advertising.

[US Iceman]

a 240 ton screw chiller from Carrier .... is only for air conditioning and we will only get 120 tons out of a 240 ton unit because they only make air conditioners. "ANY TRUTH TO THE PREVIOUS STATEMENT ?


Yes. Carrier simply build water chillers for HVAC purposes. The chillers are derated for the lower operating conditions. I have seen these used for process cooling water in rubber extrusion facilities to glycol chillers for cooling injection molding machines in plastic companies.

What the man is telling you is correct. At the lower temperatures the 240 Ton system will provide significantly lower capacity. That does not mean his equipment is defective or wrong. It simple physics and refrigeration theory.

It also means the HVAC chiller will be cheap as these are built for the huge and very competitive market. HVAC chillers only operate a few hours out of the year.

Process cooling takes place year round, so you may find accelerated wear or service problems from increased run time.

I'm in 100% agreement with Andy's comments. Especially the part about screw compressors not being used.

A rink will spend considerable time at part load operation. With screws this would be a very expensive system to operate, UNLESS, the screw compressors were very carefully selected.

Which I doubt they would be.

[giovanni]

Thanks Andy,
I should have mentioned that the unit will be outdoors so will use an air cooled chiller and will probably go with glycol due to the regulations on ammonia. IN the summer conditions are a little tough because the primary rink is a bubble.. the new one will be a regular building. WE would have to run the glycol leaving temperature about 10-15 degrees F in the summer for the bubble. We are in a shoirt period of time actually purchasing 2 chillers. One for each building

[Peter_1]

At the end of the year, at least 10 outdoor ice rinks are installed in a perimeter of 50 km around my house.
I saw them all - had you thought the opposite :D - helped with some to install and they all use normal (!) chillers, glycol added, mostly pistons, some screws.
Saw Carrier, York and also Daikin.

They are rented from the companies who rent these in
summer for process applications.

[giovanni]

[quote=US Iceman][/b]

Thank You Us Iceman

"What the man is telling you is correct. At the lower temperatures the 240 Ton system will provide significantly lower capacity. That does not mean his equipment is defective or wrong. It simple physics and refrigeration theory."

Thoughtout the year we operate from 6am to midnight with most of the volume during the hockey season. We will probably run the unit at a setpoint of 10-15 degrees F. would that be considered a lower operating temperature causing the lower capacity. We are currently renting a Trane 200 ton RTAA (2 screws). This unit has the ability to lower the setpoint to 0 degrees (currently set at 10 degrees) and the unit doesn't run all that hard. I'd say about 60-70% capacity durning business hours. Before we had a Carrier 30GT with 7 reciprocating compressors which was bought 9 years ago and during normal business hours in the summer all 7 would be running most of the time. You mentioned carefully selecting screws. We are trying to research to pick the correct size and type, Any more thoughts would be appreciated

[giovanni]

Thanks Peter 1

I am new to refrigeration and basically monitor and do routine maintenance as an end user such as cleaning, maintaining logs, etc, and was given the responsibility of doing the research because I actually enjoyed learning the workings of the unit and came to understand some of the "hows and whys" of a chiller. I am just trying to get the best possible advice and information possible. Everyone here has been extremely helpful and patient and I am very greatful, so please keep the info coming. Cant get enough info. Thanks again

[giovanni]

Thanks "No nick name"
but the powers that be have been inundated with offers and I believe they will go with Carrier. They have the final say so.

[US Iceman]

We will probably run the unit at a setpoint of 10-15 degrees F. would that be considered a lower operating temperature causing the lower capacity.


That's it exactly giovanni. The compressors have a specific pumping capacity per minute. As the evaporating temperature decreases the volume of the refrigerant vapor increases.

The required mass flow also increases.

The combination of these two changes cause the compressor capacity to actually decrease. The compressor is still pumping the same amount of refrigerant, but due to the lower evaporating temperature the cooling capacity (Tons) does decrease.

The evaporator performance also degrades due to the glycol when compared to water.

[bruceboldy]

this was an intersting issue. I come from the industrial market, like Andy talked about but I now am in the commercial area with Trane.
Icemans comment of only running hvac a few hours a day (thus reliability)is not the fact espically in Texas and the south west. Most things I see run 18 to 23 hours per day with very minimal problems, be it at 30 degrees or 0 degrees.
The Trane screw chillers are designed for ac but also for 0 degree operation as are the carrier and york units.

The industrial built up machinery has certain benefits but the commercial chillers available today work just fine and are about 50 percent of the industrial price with similar reliability..

for an ice rink that 50 percent savings is usually the deciding point . We are seeing more and more sales of the big screw chillers into the industrial market.

This type of commercial screw chiller has made a industrial guy like me a real believer....

[The MG Pony]

Some thing I have been learning well with all my studies.

Lower the temperature goes the lower the capacity, higher the temp, the higher the capacity it all most seems perfectly linear. With an Ice rink You really have two loads when you think of it, you have to cool the building, then you have to chill the ice bed.

What sounded off to me was screws are well known (Or so I've been told screws = capacity) for their capacity.

[Peter_1]

http://www.eng-tips.com/viewthread.cfm?qid=151856&page=4

http://www.wapa.gov/es/techhelp/powerline/99jun.htm

http://www.energyexperts.org/energy_solutions/res_details.cfm?resourceID=601&category=Building%2FSpace%20Type&subcategory=Sports%2FRecreation&sector=All

http://www.energyexperts.org/energy_solutions/res_list.cfm?category=Building%2FSpace%20Type&subcategory=Sports%2FRecreation
and the whole website

Soem know I love it making holes in the earth to improve efficiency http://www.arenas.qc.ca/piraq/img/pdf6828EnergyFocus.pdf

[giovanni]

Thanks for the explanation US Iceman. I learn something new everyday. Is there a simple formula to determine the loss in capacity as related to the setpoint setting? Or is that per manufacturer

[giovanni]

Thanks Bruce , we are currently using one of yours as a rental. The RTAA 200 with a capacity to lower the setpoint to 0 degrees. We are waiting for the months electrical bill to match up with past useage of the old chiller. I must say it is working fine.

[giovanni]

Thanks MG. Your right about cooling the bldg. Most of that is from the ice surface itself. WE do have additional cooling from a combination dehumidifier and a/c made by Desert Aire

[giovanni]

Thanks for the Links Peter_1

[Camille]

Rink design explanation

rink load

Dependent on the size, ambient, application
[seasonal or year around], and many other factors like building construction etc....

compressors,

reciprocating and screw compressors can be used, in Canada for a rink size of 85x200, and
seasonal application [October/March] , indoor rink you will need 85 tr, two compressors, most of the City Rinks have only two compressors

Chillers

shell & tube brine or glycol chillers, also
plate & frame chillers,
most of the rink nowadays in Canada runs with flooded Ammonia/rbine systems, ***** R22 is being phased out, we are usins flooded 134a systems

Condensers
mostly evaporative condensers with remote sump application, fluid coolers, and cooling towers can be used, all dependent on the customer requirement and building energy programs



Regards
Camille

[giovanni]

Thanks Camille.
While looking over the reasons for poor ice conditions over the years they forgot to look at the obvious. I had asked 4 years ago when I had started working at this rink why the Heat mat was at a temperature of 50 degrees F. The answer was that "it was always that way." So I didnt give it a second thought because at the time I was new to rink operations and figured the lead tech new what was supposed to be. .Well good thing I keep pretty good logs of the operating stats of the plant. He no longer works there since about 3 years ago and fortunately the Heat mat had gone down twice in the last 2 months and I noticed that as the temp went down the ice got better and the chiller unit ran a heck of a lot better also. Low and behold a little research on the simple things and now the mat is set a few degrees above freezing and we have had awesome ice this summer so far. In the past we had wet spots and soft ice throughout the summer. Its amazing how the simple things are overlooked. WE had been looking at a new chiller (which we need to purchase) and the rental we have ( all involved thought WASN'T doing the job), was due to the heat mat temp setting. What a difference now.......

[kevinmcggg]

carrier is one of the leaders in the refrigeration market. they make refrigeration compressors and transport refrigeration units. they are not limited to a/c. carlyle compressors is a division of carrier and they make what you need.

[giovanni]

Thanks Kevin, after all the research we decided on Carrier. We will be purchasing a Model 30XA 220 ton unit chiller and should have it in about 6-8 weeks

[frank]

carrier is one of the leaders in the refrigeration market. they make refrigeration compressors and transport refrigeration units. they are not limited to a/c. carlyle compressors is a division of carrier and they make what you need.

They might make what you need but I've been waiting 6 weeks now for a top end overhaul set for a Carlyle 06E compressor - as the comp has a blown head gasket at the moment the customer is not too happy :(

[giovanni]

Hi Frank, We use them for our service also and I have to say they have pretty good to us; even on big jobs...

[suave1970]

I need info. on how it works a portable Air cooled
chiller 60-80 ton for ice rink 460/3/60 low temp
(0-15 degrees) Screw RTAA or Reciprocal which?
(Glycol Ethelyne) used indoors in Venues south America... to do travel performances Ice shows...
floor size 40' X 80' feet total= 3200 sq ice floor

[Ice 33]

Hello,

I'd like to know of the companies supplying the ice rinks. Are they outdoor products or indoor only?

[Lowrider]

I need info. on how it works a portable Air cooled
chiller 60-80 ton for ice rink 460/3/60 low temp
(0-15 degrees) Screw RTAA or Reciprocal which?
(Glycol Ethelyne) used indoors in Venues south America... to do travel performances Ice shows...
floor size 40' X 80' feet total= 3200 sq ice floor

One word comes to mind: Aggreko

They rent out just about anything (machine wise). Have a talk, they've done several here in Holland!

[yinmorrison]

I know its too late now but if you want some real technical expertise talk to Star Refrigeration in Glasgow who are experts in the field of ice rink technology.