How does go about handling the refrigerant charge in a commercial ice machine?
First, there is much information about charging your ice machine on YouTube.com. The problem is that most, if not all, of these demonstrations are just plain wrong.
We looked at the first 15 or so search engine results, and each method is wrong and has nothing to do with the factory or commercial refrigeration best practices. Blindly adding or removing refrigerant is wrong, as is charging on the high side while the system is running. As Certified Master HVACR Educators, we are often confronted and asked to solve problems caused by untrained hobbyists. In the age of needing to maximize energy and water efficiency, this trend is disturbing.
This article is written for the person interested in learning more about this process and sharing that knowledge with someone else. If you are currently working as a trained HVAC technician, these processes also apply to you, particularly for mini-splits and other variable capacity systems.
The best practices for critically charging an ice machine with refrigerant involve multiple steps and considerations. To begin, it is crucial to accurately identify the type and quantity of refrigerant needed for the specific ice machine model. Once this has been established, the next step is appropriately connecting all lines, pressure gauges, valves, and hoses necessary for the CRITICAL charging process. The critical charging process requires that the refrigerant is weighed in with a refrigerant tank scale, not a bathroom or fish scale. In addition, it is essential to check the system for any leakage before starting the charging process, as introducing refrigerant into a leaking system will cause more problems down the line. The exact procedures and equipment needed for the critical charging process are beyond the scope of this article.
During a maintenance check, don’t use refrigerant charging manifold gauges to verify (what do you verify?). At every inspection, connecting hoses amounts to 4-6 % refrigerant loss. You can work out the math of what happens after doing this a few times. For an example ten-pound factory refrigerant charge, 6-8 oz. of refrigerant is lost every time the manifold hoses are connected. The effect is far more profound on smaller systems since the refrigerant loss is the same.
Once all of these preparations have been taken care of, it is time to begin charging the system with refrigerant. This should be done slowly and methodically, allowing the refrigerant to flow into the system continuously and consistently. The refrigerant scale should be monitored throughout this process to add the correct amount of refrigerant. Once the desired charge level has been reached, it is time to shut off the valves, disconnect all lines and hoses, and check for any remaining signs of leakage. Ultimately, with the right steps taken and proper knowledge applied, charging an ice machine with refrigerant can be a relatively simple task.
It is important to remember that working with refrigerants can potentially be dangerous and should only be attempted by trained professionals. If you have any questions or doubts about how to charge your ice machine with refrigerant, it is best to contact a refrigeration specialist for assistance. They will be able to walk you through the entire process and ensure that your system is charged correctly.
What kinds of refrigerant are used for ice machines?
The most common type of refrigerant used in ice machines is R-404A (also known as HFC-404A). This refrigerant is a blend of hydrofluorocarbons (HFCs) and is an environmentally-friendly option that does not deplete the ozone layer. It also has excellent thermodynamic properties, meaning it is highly efficient at cooling and creating ice. Other HFCs, such as R-410A and R-407C, can also be used in specific models of ice machines, but R-404A remains the most popular option. It is important to note that CFC (chlorofluorocarbon) refrigerants can no longer be used in ice machines.
Refrigerant blends have seemingly been under endless regulation for the past 20 years. Recently, in 2022 new blends have been implemented, with HFC and CFC refrigerant production being increasingly reduced or banned by the Federal government. Although these refrigerants are banned, they are still available as reserve stock or reclaimed refrigerant. The operative word is EXPENSIVE since the law of supply and demand is at work.
Do not mix refrigerant blends
Do not mix refrigerants unless you are prepared for significant damage to the sealed system. Refrigerant blends are not nearly the same and should not install over the top of another blend. Oil is moved about the refrigeration system in a process called miscibility. Poor miscibility equals poor lubrication and damage. We all have heard about the problems of allowing your car or motorcycle to run out of oil; it’s all awful. A similar thing applies to refrigerants and refrigerant oil.
Miscibility
Here is the technical definition of miscibility
Miscibility is the property of two substances to mix in all proportions (that is, to fully dissolve in each other at any concentration fully), forming a homogeneous mixture (a solution). The term is most often applied to liquids but also applies to solids and gases. In short, if the two don’t mix, a problem is waiting around the corner.
Many blends of refrigerant are risky to handle (flammable and-or high-pressure)
Working with refrigerants is dangerous if not handled properly, so it is crucial always to keep safety in mind. It is also essential to understand the safety precautions and guidelines that must be followed when working with refrigerants. All technicians who handle these chemicals should have appropriate training, wear protective gear, and strictly follow all manufacturer instructions and regulations. Besides, technicians must have Environmental Protection Agency (EPA 608) certification, or it is illegal to handle refrigerant in any fashion.
In conclusion, charging an ice machine with refrigerant is a complex and potentially dangerous task that trained professionals should only attempt. As a technician, if you are unsure how to charge the system properly, it is best to contact a Professional Ice Machine Technician specialist for assistance. Many tools and expensive equipment are needed to perform this task that is not economically feasible to purchase unless you work in the industry.
Heed these best practice cautions
Caution: Untrained technicians might not know how critically charged equipment is managed and do far more harm than good. The robotic ice machine cannot work correctly without the exact refrigerant charge onboard.
- If you find a technician connecting a refrigerant charging manifold, they should FIRST be challenged to find out their reasoning. The refrigerant does not leak out on its own. A leak must be present and located before adjusting the refrigerant charge. More, refrigeration problems in a well-maintained or new ice machine are a minuscule percentage of actual unscheduled service issues.
- Simply adding or removing refrigerant from an ice machine to acquire a fictional performance metric is just flat-out wrong. The required charging methods must be used, or the refrigerant charge is wrong.
It should be noted that many types of HVACR equipment fall under the critical charging requirement, such as HVAC systems, mini split systems, small refrigeration equipment, and much more. If you’re unfamiliar with the technique, we encourage you to receive training and use it on your next job.
