Ed Whinyates of Stonegrove Refrigeration explains why this natural refrigerant is a logical long-term solution with the right installation and operation.
Ammonia is a natural refrigerant that has been used across a number of industries for more than 150 years. The food processing and temperature controlled storage industries use ammonia as the refrigerant of choice in many industrial applications. The continued phase-out of man-made refrigerants has had an impact on end users considering the use of natural refrigerants.
With a Global Warming Potential (GWP) of 0 and zero Ozone Depleting Potential, ammonia offers a level of security and reassurance that F-gases will never be able to achieve under current legislation. Being eco-friendly, as well as energy efficient, the long term suitability of ammonia is excellent.
There are a number of challenges to installing and running an ammonia refrigeration system. Even though ammonia is a natural refrigerant, it is highly toxic and flammable. Because of this there are UK and EU laws and regulations in place that apply to ammonia in refrigeration. These ensure the safe installation and operation of refrigeration systems. The key ones are as follows: The Pressure System Safety Regulations 2000 (PSSR), Provision and Use of Work Equipment Regulations 1998 (PUWER), EN378:2016 Refrigerating systems and heat pumps – Safety and environment requirements (Part 1-4), EN12693:2008 Refrigeration systems and heat pumps – Safety and environmental requirements –Positive displacement refrigerant compressors.
What to be aware of
There are some important things to be aware of when using ammonia. It is a hazardous gas. Nonetheless it has a distinctive pungent odour which can normally be detected by smell - even in concentrations as low as 5 parts per million. It has been acknowledged that people who are used to it are able to work without discomfort in concentrations of approximately 100 parts per million. That being said, the consideration and implementation of safe design and operation of refrigeration systems is incredibly important - especially as ammonia becomes flammable at concentrations of between 16% and 25% by volume in air.
Industrial refrigeration companies, like Stonegrove Refrigeration, fully understand the risks from ammonia. It is vital to offer the end client a high level of reassurance, by designing and installing safe refrigeration systems. There are a number of ways to ensure this happens.
Industrial refrigeration companies are able to manage the risks by understanding ammonia refrigeration technology and the science of ammonia. Systems are designed, selected, installed and maintained correctly. We identify likely sources of leaks, so appropriate plant checks can be carried out by trained personnel. Effective control, monitoring, preventative and protective measures are put in place to meet the specific requirements for Health & Safety regulations.
Designing and installing
Every ammonia refrigeration system should start with an experienced designer. When selecting refrigeration plant, they have been trained to understand risk and eliminate or minimise it through knowledge, experience and continued improvements in technology. By applying all of these they are able to comply with all current regulations such as PUWER, PER, PSSR, and DSEAR. Designers will also ensure that installed refrigeration plant complies with BS EN 378 Refrigeration systems and heat pumps, Safety and Environmental requirements – Parts 1-4, and the IOR guidelines for Safety Code of Practice for Refrigerating Systems Utilising Refrigerant R-717 (Ammonia). All systems will have safe operating limits established to prevent the likelihood of system failure.
Maintenance and training
It accepted that training is the common factor to improving the safety record for ammonia. By training operators and maintenance engineers, it avoids errors that lead to the risk of serious harm or injury. Risks like these are dealt with by the development of appropriate risk assessments and safe systems of working (or method statements). This applies to any work that may expose personnel to risks and ensures the use of appropriate PPE, such as impervious clothing and gloves, use of goggles etc. Risk assessments also identify the safety critical features of refrigeration plant, so targeted maintenance is implemented to detect signs of potential problems. Companies like Stonegrove will always provide a recommended schedule for inspection and maintenance.
Although ammonia itself can be viewed as dangerous, it has been said that ammonia systems are the safest. Ammonia systems are heavily regulated, particularly for those with larger charges of refrigerant. However, even industrial applications don’t necessarily require large amounts. Ammonia can be used in smaller charges, with a secondary refrigerant such as CO2 or Glycol. This method can also lend itself to smaller applications. Industrial refrigeration companies that work with ammonia have experienced designers and engineers who are trained and compliant right through the process of design, installation, commissioning and continued planned preventative maintenance. Using natural refrigerants, like ammonia, is the logical step in the continued evolution of the refrigeration industry.
To find out how Stonegrove can help with your refrigeration requirements, contact 01279 408690.