RINK REFRIGERATION 101 part 1 of 6 This year RINK Magazine will discuss refrigeration in an educational 6-part series.

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1 part 1 of 6 This year RINK Magazine will discuss refrigeration in an educational 6-part series. This information can be shared with your staff to promote some good discussion and possibly even enhance the ability of your operations staff. We encourage you to share your comments, ideas and repairs related to rink refrigeration systems by sending them along with pictures to davew@starrinks.com. Reading & Reacting by DAVE WESCOTT We ll start this series from the beginning where, unfortunately, the typical rink refrigeration system training between experienced and new operators goes something like this: This is the refrigeration plant, DON T TOUCH ANYTHING. Just read these gauges and call me if something is wrong. Through this series of articles, we are hoping to help get this type of training to progress a little further. While we do recommend that a bound book be used to add credibility to the refrigeration logs, at a very minimum create your own log that is tailored to your equipment. There are preprinted logbooks available from STAR and some refrigeration manufacturers. A logbook is good for risk management and accountability. However, when it comes to refrigeration logs, troubleshooting and maintenance are the main benefits of keeping detailed information. A good refrigeration service company will check out the refrigeration logs before performing any maintenance on While reading and recording the gauges is part of the job, understanding the readings is critical to trouble shooting and maintenance. the system. During routine maintenance visits, the information in the logs will let the refrigeration mechanic see how the system has been operating and alert them to any abnormal conditions that may exist. RINK PHOTOS 48 R INK MAGAZ INE january/february 2010 STARrinks.com

2 Making sure the operators know and understand what the gauges are reading, and the proper limits for these readings, is very important. There are many stories from refrigeration mechanics who have found refrigeration logs revealing improper readings. If the refrigeration mechanic is there for an emergency call, such as the system being down, the refrigeration logs can help troubleshoot the problem and, in most cases, save valuable time and effort in getting the system running again. Reviewing a sample logbook page will give you a good idea of the items that need to be recorded. The main suction and discharge pressures are indicators of the heart of the system, and how it is functioning. Brine/Glycol supply and return temperatures let the operations staff know that the system is holding the temperatures needed for good ice conditions. Making sure the operators know and understand what the gauges are reading, and the proper limits for these readings, is very important. There are many stories from refrigeration mechanics who have found refrigeration logs revealing improper readings. However, because of a lack of training, the operators taking the readings never alerted anyone and the refrigeration plant failed. Therefore, it is very important to train the operators reading the gauges and make sure they understand what they mean and what the proper readings are. Basic Refrigeration Courses are being offered by STAR in many locations across the country this year. This is great training for staff that is responsible for monitoring refrigeration equipment. Graduates of the Basic Refrigeration course have returned to their facilities and have immediately been able to help get your logbook today! Order by contacting STAR at info@starrinks.com operate the plant more efficiently and save some money on service calls, as they themselves were able to troubleshoot and solve minor problems. Many of them saved much more money then was spent to send them to the training! STARrinks.com january/february 2010 RINK MAGAZINE 49

3 part 2 of 6 This year RINK Magazine will discuss refrigeration in an educational 6-part series. This information can be shared with your staff to promote some good discussion and possibly even enhance the ability of your operations staff. We encourage you to share your comments, ideas and repairs related to rink refrigeration systems by sending them along with pictures to davew@starrinks.com. Understanding What Controls Refrigeration Plant Temperature Settings by DAVE WESCOTT Do you know exactly how your refrigeration plant is controlled? If not, you could be missing out on an opportunity to operate the plant more efficiently. Most refrigeration plants built before the 1980s relied on a thermostat in the return brine line to control the operation of the compressors. While this was a reliable way to control the compressors, it was not the most efficient system because of the delayed reaction time. This design also requires the brine/glycol pump to run continuously to ensure that the thermostat receives the current brine/glycol temperature. Running the brine/glycol pump this way can cost as much as $500 to $1,000 more per month in energy costs. When using the return brine/glycol thermostat to operate the compressors, any heat that is applied to the ice slab (such as resurfacing) has to pass through the ice, into the rink floor pipes. The heat then must enter the secondary refrigerant (brine/glycol) where it is carried back to the compressor room so that the brine return thermostat can sense the heat load and activate the compressors. This is a long lag time for the compressors to react. The ice technician must recognize that the reverse needs to occur once the ice surface is back down to the set operating temperature. Note: The system will not shut down until the brine/glycol has reached a lower temperature than the ice sheet, which may make the compressors run more than required. Technical advancements in the 1980s Understanding the controls and making adjustments can save you money. Facilities that have multiple controls should operate each independently to determine which runs the system most efficiently. saw slab sensors become a more reliable way to operate the compressors. When using a slab sensor, the heat put onto the ice surface only has to travel down through the ice where the slab sensor reacts to activate the compressors. This occurs regardless of whether or not the brine/glycol pump is running. Once the RINK PHOTO 48 R INK MAGAZ INE march/april 2010 STARrinks.com

4 slab reaches the proper temperature, the system should control the compressors to hold the temperature of the slab. In the 1990s, infrared temperature sensors became an option to operate the refrigeration plant. The reality is the ice surface temperature is the primary concern of the ice technician. Infrared sensors react quickly by sensing the heat load of not only the ice resurfacer when it starts to work, but also a large user load or a hot day that warms up the ice surface. The infrared sensor will work to keep the ice surface at the set temperature. The infrared sensor will also identify when the surface is back down to the set operational temperature, and will shut down the compressors at the set surface temperature. Infrared systems will also help prevent the temperature of the ice from getting too cold from outside temperatures, offering energy savings. Wireless temperature probes used in the ice floor at the NHL Winter Classic Game. Facilities that have multiple controls for their compressor system should consider having the ice technician operate each independently in order to determine which runs the system the most efficiently. It is worth stressing the importance of always being careful not to operate your compressors in a manner that adversely affects ice quality. Learn your system, operate it properly and save energy in the process. RINK PHOTO The Industry s Leading Arena Management Software Offering fering Maximize Your Organization s Potential Maximum Solutions Inc. Facility Scheduling League Management Membership Management Multi-Use Pass & Attendance Tracking Walk-in & Online Registration ion TV Schedule Display & Advertising Point of Sale Inventory Management Locker Rental & Tracking Equipment Rental &Tracking Credit Card Processing Financial Software Integration tion Energy Controls Integration n Website Integration Billing & Receivables Contact Management Employee Time Clock Gift & Pre-Paid Debit Cards Over 175 On Demand Reports ww. Toll Free info@maxsolutions.com STARrinks.com march/april 2010 RINK MAGAZINE 49

5 part 3 of 6 This year RINK Magazine will discuss refrigeration in an educational 6-part series written by Dave Wescott. This information can be shared with your staff to promote some good discussion and possibly even enhance the ability of your operations staff. We encourage you to share your comments, ideas and repairs related to rink refrigeration systems by sending them along with pictures to davew@starrinks.com. What type of refrigeration plant do you have? This is the first question to ask as many rink operators may not be sure what type of refrigeration plant is in their building. While it might seem like it s OK not to know your system because someone else takes care of the maintenance, it is important to understand how things works in order to talk to service contractors intelligently. If you don t have a basic understanding of how things work, you are leaving yourself exposed to potentially being taken advantage of when it comes to service and repairs. Some of the basic information you need to know about your system includes: Is your ice plant a direct system or an indirect system? Direct systems only use primary refrigerant to cool the rink floor and have a large amount of this refrigerant, somewhere between 3,000-5,000 pounds per rink. Freon would be the only refrigerant used in this type of system. Indirect systems use both a primary and secondary refrigerant. The primary refrigerant will remain in the ice plant and condenser. The secondary refrigerant will be circulated between the ice plant and the rink floor. This is the most common system used in the U.S. What type of primary refrigerant does your system use? The two main types of primary refrigerants used in ice arenas are freons and ammonia. The primary refrigerant is the substance that removes the heat and will be in a liquid state. As it picks up heat it boils and changes to a vapor/gas which takes the heat and goes through the compressor and ultimately out to the condenser that rejects the heat outside the building. You should also know what type of freon you have (R22 or R134A, etc.) if that is your primary refrigerant. What type of secondary refrigerant does your system use? The two main types of secondary refrigerant are salt brine (calcium chloride) and glycol (ethylene or propylene). The secondary refrigerant is the substance that removes the heat by not changing state. The secondary refrigerant will remain in a liquid state as it is pumped through the pipes in the rink floor and returns to the chiller (evaporator) in the compressor room. In rare cases you may find methanol used as a secondary refrigerant. What type of condenser does your system use? Evaporative condensers are the most common type used in ice arenas. This type of condenser uses air and water to cool the hot gas in the pipes running through the condenser. This also requires that the system have enough primary refrigerants to be piped out of the building to the evaporative condenser. Water-cooled condensers will work in combination with a cooling tower to allow water to run between the tower and condenser. This system keeps the primary refrigerant in the compressor room where a smaller amount of primary refrigerant is needed. Only water is piped out of the building and circulated between the water-cooled condenser and the cooling tower. Air-cooled condensers are primarily used in northern U.S. locations and also with seasonal rinks, due to their limited capacity to cool in hot temperatures. These condensers are located outside and will have the hot gas primary refrigerant piped out to them. These look like large, flat aluminum beds with lots of fans running on top of them. What type of compressors do you have? The most common type of compressor used in ice rinks is the reciprocating compressor. This compressor works much like a car engine with pistons and valves doing the work.like a car engine, it requires regular maintenance to operate efficiently. We are seeing more screw compressors being used in the rink industry lately and, since they are more efficient and require less regular maintenance, this trend should continue. With geo-thermal systems, scroll compressors are being used for rink refrigera- 52 R INK MAGAZ INE may/june 2010 STARrinks.com

6 tion. Scroll compressors are used in home refrigerators and are sealed, requiring no regular maintenance. However, when they do fail, they have to be completely replaced. Knowing the manufacturer, size of your compressors and the electric motors that drive them is essential for rink operators. Arid-Ice Controlled Dehumidification Solutions And lastly, what type of chiller (evaporator) does your system use? For facilities with direct systems, this does not apply as direct systems use the rink floor as the chiller (evaporator) to remove the heat and turn the liquid primary refrigerant into a vapor/gas. The chiller is a very important part of the indirect refrigeration system because it is in the chiller that the heat from the secondary refrigerant (brine/glycol) is transferred to the primary refrigerant (Ammonia/Freon). This heat transfer has to take place without the two substances mixing with each other. The main type of chiller used in ice rinks is the flooded chiller. This type of chiller floods the tubes full of secondary refrigerant inside of a shell with the primary refrigerant. The second most common type of chiller used in ice rinks is the dry chiller (also called direct expansion chiller). This type of chiller floods the tubes full of primary refrigerant inside of a shell with the secondary refrigerant. The use of plate and frame chillers in ice rink applications is becoming more prevalent. These chillers are much smaller in size and are more efficient for transferring the heat from the primary to the secondary refrigerant. Plates are used instead of tubes and a shell for larger surface area, creating more heat transfer for the size of the unit. Any and all rink operators should know which of these systems and pieces of equipment are used in their rink. If they don t, the Basic Refrigeration course offered by STAR would be able to bring anyone up to speed on these systems. STARrinks.com Don t Rob Your Refrigeration System to Dehumidify Your Rink. ARID-Ice is the most effective and efficient gas fired desiccant system using reactivation recovery options and dew point controls to maximize performance and minimize total energy consumption. ARID-Ice units are equipped to reduce humidity levels, eliminate indoor condensation and fog, prevent mold, reduce refrigeration costs and improve indoor air quality, these systems utilize natural gas, steam or electric reactivation. CDIMS is the premier supplier of desiccant dehumidifiers. We have provided equipment for over 300 skating surfaces throughout North America from 500 to 45,000 SCFM. For ARID-Ice sales and equipment specifications, call Arid-Ice CDIMS Controlled Dehumidification Solutions 5931 Ford Court Brighton, MI Fax: sales@cdims.com may/june 2010 RINK MAGAZINE 53

7 part 4 of 6 This year RINK Magazine will discuss refrigeration in an educational 6-part series written by Dave Wescott. We encourage you to share your comments, ideas and repairs related to rink refrigeration systems by sending them along with pictures to davew@starrinks.com. Start-Up and Spare Parts In this installment we discuss the start-up of the refrigeration plant and the importance of spare parts for your refrigeration plant. First off, we recommend that seasonal start-ups be performed by your refrigeration service professional. However, we also recommend that rink staff assist in the startup and learn how the procedure works, as well as learning as much as possible about the refrigeration system at your facility from your service company. Add this knowledge with the information your employees can receive from a Basic Refrigeration class and your facility will benefit greatly. Seasonal start-ups give you a chance to make sure your plant is operating efficiently. During the shutdown period you have the opportunity to clean, inspect and evaluate your refrigeration equipment. It s a good idea to check out the refrigeration room a couple of weeks before the scheduled start-up and complete a list of prestart-up procedures. This list of prestart-up operations should be developed with your service company and will be specific to your system. There will be items like inspecting drive belts and couplings and checking valves for leaks and proper operation along with the refrigerant and oil levels. The Chicago Blackhawks will sure be looking forward to Start-Up of this plant next year. If you wait until it s too close to start-up time to perform the pre-startup checks and find out you need something replaced or repaired, you may not have the time to get the parts and complete the repairs before start-up. The last start-up item is to schedule plenty of time to make the ice. Planning one extra day for any unexpected delay is always a good idea. Another topic that goes Sample pre-start Procedures hand in hand with the start-up is having a good inventory of spare parts. There have been many plant start-ups that have been interrupted by a lack of spare parts. Some facilities are fortunate to be located in major cities that have parts within a day or Check seal on water pump for leaks Check spray nozzles on condenser make sure they are not plugged Check all water and brine valve stems Check all v-belts for wear/cracking Grease all bearings Check brine headers for corrosion wire brush & paint if necessary Conduct an internal inspection of compressors (to manufacturer s specifications) Check brine/glycol level and strength (specific gravity) Drain the chiller of oil ammonia systems Replace oil in compressors check lines\filters Check seal on brine\glycol pump for leaks Drain/clean condenser water tank Drive Belts are a very important part to have on hand. two of the facility. However, for facilities located in more remote places it can take longer to receive parts, so having spare parts on hand is invaluable. It s a good idea to create a spare parts inventory with both your manufacturer and service company. Things to consider: batteries for your computer controls, back-up software or discs, fuses, motorstarter contacts, relays and coils. Also consider belts for the compressors and condenser and drive couplings for compressors and pumps. If not locally available, a spare condenser motor should be considered since there is no redundancy for it and ice could be lost without it. Preparation is the most important part of the start-up process the turning of valves and flipping of switches is the easy part. So, make sure you are prepared! 42 R INK MAGAZ INE july/august 2010 STARrinks.com

8 part 5 of 6 This year RINK Magazine will discuss refrigeration in an educational 6-part series written by Dave Wescott. We encourage you to share your comments, ideas and repairs related to rink refrigeration systems by sending them along with pictures to davew@starrinks.com. Keep It Clean! For those of us fortunate enough to have opened a new facility, we can all remember how nice it was to go into a nice, clean refrigeration room, with a dry floor. Now fast forward five years and see if this sounds familiar: the floor is wet in a lot of spots, oil is under the compressors, ice has built up where repairs have been made, insulation hasn t been replaced, the oil drums are stacked up and the room has become a storage area for everything from plywood to motor oil! If in addition to the disorder already described, your refrigeration room has become the operations storage shed, it s definitely time to clean it up. The refrigeration room is the heart of your facility and should be treated as such. Access to this area should be restricted to trained personnel only and the doors should be locked at all times. These are dangerous areas with moving parts and hazardous chemicals that demand respect. All of our facilities have children in them, and keeping kids out of areas like the refrigeration room is very important. If your room has already deteriorated, the first step is just getting the access to the room under control. Once this is accomplished, a thorough inspection of the room should be done with staff and the service company. Identify all items that need to be addressed and try to prioritize them, with safety-related items being first on the list. It s best to create two lists, one that the staff can work on and another that the service company can work on. Each week assign the staff an area of the room that is safe to work in to accomplish cleaning and painting tasks, and keep the work in process going until the room is back in shape and looking good. So why should keeping things clean be a priority in an already busy facility? As with most mechanical equipment, the cleaner it is the better it runs. Electric motors, for example, will last longer and run cooler if they are not covered in dust and grime. The most important and costsaving reason to have a clean refrigeration room is for the discovery and trouble shooting of equipment problems. RINK PHOTO 32 R INK MAGAZ INE September/October 2010 STARrinks.com

9 Imagine going into a room day after day and seeing water and oil on the floor and dirt on the pipes, compressors and motors. Eventually you will not be looking for things out of the ordinary because it looks bad all the time. If a new leak develops it could be days before it s discovered. Now imagine going into that same room and it s clean and dry. As soon as a leak of any type develops it will be noticed right away, possibly saving time and money on repairs. Personal pride should be another factor in maintaining a clean equipment room. After showing pictures of the Chicago Blackhawks refrigeration room to other NHL building operators at one of their meetings, many other rink operatorss worked at getting their rooms as nice as Chicago s, including adding team logos. When your staff keeps the equipment The Chicago Blackhawks added team logos to their refrigeration room as a nice touch. room clean it will keep the pressure on your service company to do the same. If they are led to believe that you don t care how the room looks, they will not care either and just add to the mess. So remember, Clean is Keen! RINK PHOTO ICE RINK DESIGN From the Leader in Ice Rink Technologies With over 4,500 ice surfaces installed around the world, CIMCO Refrigeration can provide a range of expertise unmatched by any other company. For design, installation and service of new or existing refrigeration systems, you can rely on CIMCO. Call us today to learn more about our newest, most energy-efficient system Wallingford, CT Mobile, AL Van Buren, AR Louisville, KY Ponte Vedra, FL R INK MAGAZ INE September/October 2010 STARrinks.com

10 part 6 of 6 This year RINK Magazine will discuss refrigeration in an educational 6-part series written by Dave Wescott. We encourage you to share your comments, ideas and repairs related to rink refrigeration systems by sending them along with pictures to davew@starrinks.com. Efficiently Removing Heat and Energy As any STAR Basic Refrigeration class graduate can tell you, the definition of refrigeration is the removal and transfer of heat under controlled conditions. The refrigeration system in your rink is not making the ice sheet cold; it is actually removing heat from the ice sheet. The resulting temperature is then below the other areas of the building and below the freezing point of water. The condenser, the single most important piece of equipment in the refrigeration system, removes heat and controls operating pressures. There are three types of condensers: water-cooled, aircooled and evaporative (combination of water and air). Hot refrigerant gas (ammonia or freon) is moved through the condenser by the compressor or compressors. The gas is cooled in Water treatment is very important for evaporative and water-cooled condensers. The classic evaporative condenser. the condenser, causing it to condense back into a liquid before it goes back into the evaporator (chiller). When the refrigerant gas is cooled to the condensing point, latent heat of vaporization occurs and the heat in the gas is released, allowing the gas to condense back to a liquid. In most refrigeration systems the condensing point is usually about 90 degrees Fahrenheit. If a condenser gets a build up of dirt or mineral deposits on its coil of tubes, or has poor air and/or water flow it will make it harder for the gas to condense to a liquid. Also, if the outside air temperature is close to the condensing point of the system (summertime), the condenser will be less efficient at condensing the gas. Both of these conditions will cause the pressure to rise in the high side of the system. When the high side pressure rises, the compressors must work harder to move the gas, using more electricity. Unfortunately, some facilities have undersized condensers and therefore run consistently high pressures, causing higher utility bills and extra RINK PHOTOS 34 R INK MAGAZ INE november/december 2010 STARrinks.com

11 ANOTHER YEAR OF GREAT ICE! Professional Ice Painting Services This is how a nice, clean evaporative condenser should look. wear and tear on the compressors. Getting your condenser to work properly will take some routine maintenance. Most ice rinks operate with an evaporative condenser because they are the most efficient type. These condensers use air and water circulated over tubes in the unit to cool off the hot gas. Just 1/16 inch of mineral scale build up on the tubes will cut the heat removal efficiency dramatically. Chemical water treatment of the condenser cooling water is critical to limit this mineral build up. However, even with chemical water treatment, it is important to manually clean the outside of the tubes and water nozzles regularly. Water-cooled condensers use water circulated through tubes that are surrounded by the hot refrigerant gas. This type of condenser will also get mineral build up inside the tubes, making chemical water treatment very important. Manually cleaning the tubes must be done regularly to maintain proper water flow through the tubes. This cleaning process usually includes running a rod with a brush on the end to clean out the tubes. Air-cooled condensers are the least efficient of the three types of condensers, but also require the least amount of maintenance. The only regular maintenance needed to keep these condensers running efficiently is pressure washing dirt and debris off the coils. However, in warm weather air-cooled condensers can struggle to condense the gas completely. If you start to notice your high side pressure increasing gradually over a period of time or experience sudden rise in pressure, take a look at your condenser. Dirty coils, clogged water spray nozzles, faulty water pumps, broken fan belts and faulty fan motors are the major culprits of high pressure. Remember that when high side pressure goes above its normal operating range, you can be sure your electric meter is going up too! Professional Repair & Installation Services premium ice paints You Can t Get Any Whiter! Simple One-Step Mixing Process Advanced Ultra-Hide Formula Highest Quality Materials Odorless! Economically Priced Custom Colors 100% MADE IN THE USA All first time customers receive 25% off Initial Order! RINKSPECIALISTS.COM ULTRAPUREPAINTS.COM STARrinks.com november/december 2010 R IN K M A G AZ I N E 35