As a part of our series of articles focusing on commercial refrigeration repair cases, we would like to share a real-life example of a common problem that one of our customers encountered. This week, at Pacific Appliance Repair Services, we had a customer call us about a problem with their commercial refrigeration system because it was not cooling properly. Of course, cooling is the main function of a refrigerator or freezer, so this in itself is a very vague description of actual malfunction. The specific problem turned out to be a leak in the system.
First, we checked all the components to see if anything was not working as it should. The components were all operating, and most of these either work or they don’t. The fans were on, the compressor was working, and so on. So, we suspected that the issue might be within the pressurized refrigerant system, with Freon not controlling the cooling temperature correctly.
There is a relationship between pressure and temperature in gases is described by the ideal gas law, which states that the product of a gases pressure and volume will be directly proportional to the product of its temperature, molecular quantity, and a constant. So basically, as pressure goes up, so does temperature, all things equal. Because the system makes use of various physical properties through its parts in an exact way to render the refrigerated area within a narrow temperature range, it is absolutely essential that everything be functioning accurately, and the Freon be at its correct pressure for the required temperature in a refrigerator. Sometimes, the quantity of Freon can be reduced over time through a leak in the system, which is not supposed to happen if all systems are functioning properly. However, when it does, it can happen at different rates, just like any leak. And like most leaks, it should be fixed. In refrigeration, and especially commercial refrigeration, it is imperative that any substantial leak is fixed immediately.
In this case, we identified that there was indeed a leak in the system. Again, our initial clue was that everything else was working fine, but the refrigerator temperature was too much too high. Also, the temperature decrease wasn’t slow and gradual enough to be disregarded and remedied with periodic Freon recharging or distributing stop leak material inside the system to plug the tiny hole. So, we conducted a leak test. There are a few ways to do this. Sometimes, ultraviolet dye can be pushed through the system to identify the leak. Alternatively, it can be identified by sound. Most of the time, the leak in the Freon system is found through a visual inspection using the help of hyper-pressurization and a special leak identifying soap formula.
Normally the pressure within the high side of the system is well under 100 PSI, but in order to make sure that any leaks are identified, we use a gas pressurized at 400 PSI. This, in combination with a formula that bubbles conspicuously in response to airflow, allows us to find the leak. We cleared out the Freon into an appropriate tank and vacuumed the system first, then added safe Nitrogen gas pressurized to 400 PSI. We listened for the area of the leak, and then sprayed our soapy leak detection formula onto this area of the gas line.
As you can see, the leak causes the formula to bubble in its location. Here is a closer look at where Freon was leaking in this commercial refrigeration system.
Having found the Freon leak by using Nitrogen gas and our leak soapy formula, we can see clearly where the gas is escaping.
Next, we replaced this area’s old piping with a new pipe, creating a perfect seal so that the system can remain at its proper pressure, and thus, the refrigerator stay cold at the right temperature.
After this, we pressurized the system again at a high pressure, and monitored our gauges. The pressure remained constant, meaning that no gas was escaping, and that there was no more leak. Finally, we removed the Nitrogen and replaced it with Freon at the right pressure for this system, to keep it at its desired temperature. Now this commercial refrigerator works perfectly!
DISCLAIMER: We choose certain real repair jobs that we’ve done in the previous week(s) to share our experience and spread the knowledge about residential and commercial appliance repair, air conditioning repair and heating repair practices. All materials in this article are intended for informational purposes only and should not be used as a professional advice or to conduct formal training, educational or licensing procedures. It is also not intended as a guide for any kind of do-it-yourself repairs. Appliance repair, air conditioning repair and heating repair services can only be provided by a trained and licensed technician. Pacific Appliance Repair Services disclaims any and all responsibility for any damages, direct or indirect to property or health or life of persons that may result out of incorrect use of this information. If your appliance, air conditioner or heater is broken, please contact us immediately, and we’ll send a trained and qualified technician to repair it.