There has been a push to take advantage of the benefits of ammonia while reducing the risks—and it has resulted in an innovative solution: low-charge packaged refrigeration equipment that uses ammonia or CO2 and a secondary refrigerant (such as glycol). This allows facilities to reap the benefits of ammonia’s excellent thermodynamic properties while minimizing the charge and risk. This new type of system is “packaged” or “modular,” with refrigeration equipment built off site, mounted on a structural steel base, and delivered to your plant as a self-contained, “plug-and-play” system. Because it uses secondary refrigerants, which isolates ammonia to the machine room and only uses about one pound of ammonia per ton of refrigeration, the charge is minimized.
Here are five benefits of low-charge packaged refrigeration equipment utilizing a secondary refrigerant:
- Enhanced safety—Secondary refrigerant systems reduce the total quantity of primary refrigerant. Ammonia is isolated to the machine room, reducing the risk to plant personnel in the event of a leak. This means that no ammonia is in the process space and ammonia detection is not required in multiple rooms. Facilities with more than 10,000 pounds of ammonia must comply with Occupational Safety and Health Administration (OSHA) rule 29 CFR, but secondary refrigeration systems use less than that amount.
- Space savings—Each packaged unit is comprised of refrigeration equipment mounted on a structural steel base, complete with interconnecting piping, valves and instruments. Because refrigeration components are incorporated and compacted into one, single unit, these natural chillers assume a smaller space within the facility and do not require a large machine room.
- Lower total cost of ownership—Ammonia is less expensive than hydrofluorocarbons (HFCs) and other refrigerants. For example, it takes six volumes of R134A to produce the same cooling effect as one volume of ammonia. Because of the lower energy cost, low-charge packaged refrigeration equipment is cost competitive over its lifetime.
- Installation benefits—Modular refrigeration equipment is built in a controlled facility, which makes the process more efficient and less dangerous for those constructing it. Packaged refrigeration systems are cheaper and safer to build and install thanks to less onsite construction.
- Use of environmentally friendly refrigerants—Ammonia does not harm the environment and has zero ozone depletion potential (ODP) and zero global warming potential (GWP). In July 2015, via the Significant New Alternatives Program (SNAP), the Environmental Protection Agency (EPA) announced the delisting of the use of R134A, R404A, R507A and other high-GPW HFCs as of 2017 or later. Under SNAP, each application with a delisted HFC is approved for the use of a natural refrigerant like ammonia. Exactly what lies ahead in terms of legislation and oversight has yet to be determined; however, strict regulations on the use and phase-out of high-GWP refrigerants is certain.
To learn more about the benefits of packaged refrigeration equipment, download our Packaged Refrigeration Equipment Buyer’s Guide.
About Stellar
Stellar is a fully integrated firm focused on planning, design, pre-construction, construction, refrigeration, mechanical & utility, building envelope, and total operations & maintenance services worldwide. Visit the company's blog at www.stellarfoodforthought.net
