Issue link: https://read.uberflip.com/i/1490145
46 / JANUARY.FEBRUARY.2023 USICERINKS.COM Safety procedures and new requirements for ammonia refrigeration detection systems by Paul Golomski, CIRM Code Red A NHYDROUS AMMONIA IS ONE OF THE MOST COMMON PRIMARY REFRIGERANTS USED IN ICE RINKS TODAY. With the recent phasedown of R22 (Freon), it has become the primary refrigerant of choice for many new ice rink refrigeration systems. Ammonia is a natural refrigerant with low global warming potential. With good safety processes, current leak detection standards, sufficient con- trols, and proper PPE, ammonia is a very safe refrigerant. It has the highest latent heat of vaporization of any available refrigerant, making it the most efficient refrigerant on the market. However, ammonia gas is highly toxic and must be monitored continuously to ensure employee and public safety, espe- cially in confined spaces. The incident in Fernie, B.C. in 2017 is a stark reminder on the importance of safety procedures and controls within a refrigeration system. NEW REQUIREMENTS ANSI/IIAR (International Institute of Ammonia Refrigeration) codes relating to ammonia detection and ventilation changed in 2021. Newly constructed ammonia plants must comply with these codes. It is highly advisable that all ammo- nia refrigeration plants be upgraded to meet these requirements for safety, secu- rity, and liability purposes. Along with the new detection codes will also bring the requirement for employee training and SOPs relating to safe entrance and emergency procedures. OSHA allowable limits for ammonia exposure over an eight-hour timeframe is 50ppm (parts per million). They define 300ppm as immediately dangerous to life and health. It is not unusual to have minor leaks from refrigeration equip- ment and normal ammonia loss occurs at every oil drain cycle. It is the plant operator's responsibility to have these leaks repaired quickly and safely. The gas detection system that is installed in your plant will require consultation with a reputable industrial refrigeration company. Each site will have slightly different needs based on plant design and room size. Your system should be designed up to current ANSI/IIAR codes. PETTIT'S INSTALL We recently installed a new ammonia detection system at the Pettit National Ice Center in Milwaukee, Wis. Our system came equipped with the following items: the main gas detection controller, remote ppm display at indoor entrance, three ammonia sensors, battery backup UPS, four (green, orange, red) light stacks with horn/strobe built in, and a silence/reset switch. The system func- tions much like a fire panel does. Our installation was done in four phases. Phase 1 was wall-mounting equipment. Phase 2 was electrical, conduit, and wiring. Phase 3 was startup and commissioning. Phase 4 was integration into our controls/ automation system. The system requires a separate private electrical circuit for the main controller to feed power to sensors, horns, strobes, and remote displays. It should also have a UPS backup power source in case of power loss. Each plant will need two low-level sensors in case of failure of a single detector. These sensors are electrochemical sensors and are used for low concentrations of 250ppm or less.