You may have heard it said that refrigerants are the lifeblood of many types of HVAC and Refrigeration equipment. It’s a good analogy because without sufficient refrigerant levels, the equipment can’t function properly. That’s just one reason why refrigerant leak detection is so important (we’ll get to a few more in a moment).
Like blood in the body, refrigerant circulates in a closed loop in HVAC and Refrigeration systems. Theoretically, refrigeration levels should stay the same. However, refrigerant lines and coils can develop corrosion, leading to cracks and holes where refrigerant can leak out. When refrigeration levels are reduced due to leaks, the system can’t cool as effectively. If the leak is not found and fixed, eventually the equipment can’t cool at all.
As a technician, it’s your job to find what can be a tiny hole in very long refrigerant lines.
The problem is, unlike blood, refrigerant is an invisible gas so it’s not always easy to spot a leak.
In this article, we’ll explain why refrigerant leak detection is essential; today it’s about more than equipment operation. Then we’ll look at the pros and cons of different refrigerant leak detection methods.
Why refrigerant leak detection is so important
Sometimes systems develop tiny holes causing very slow refrigerant leaks that may take a while to impact equipment performance. You may wonder why refrigerant leak detection is so urgent for small leaks. Here’s why.
Prevent equipment breakdowns
When an air conditioning or commercial refrigeration system doesn’t seem to be reaching the set temperature, or is running constantly in an effort to do so, a refrigerant leak may be to blame. When you can find the leak, repair it, and recharge the refrigerant to the proper level, you can prevent the system from breaking down completely.
Your proactive action can save the system from further damage and the customer from a more expensive repair bill. Food service businesses can lose customers and revenue when refrigeration equipment is down. The same can happen to retail stores and other types of businesses due to air conditioning breakdowns.
Save energy
Systems that have a slow refrigerant leak will run longer as they struggle to cool. That uses a lot of excess electricity and can cause the system owner’s utility bills to skyrocket.
Risk to the environment from leaking chemicals
It’s no secret that many refrigerant chemicals commonly used in air conditioning and refrigeration systems are harmful to the environment. Some are known to cause damage to the earth’s ozone layer, and others are greenhouse gasses that contribute to global warming.
As a service technician, it’s your responsibility to help keep those refrigerants safe in the closed-loop systems where they belong and not leaking out into the atmosphere.
Need to recycle refrigerants being phased out
Due to the environmental risk, certain refrigerants are being phased out as per the U.S. EPA. So the supplies are going down year by year (and prices are going up, too). However, there are still plenty of older systems out there that use these refrigerants, and the older refrigerants are still needed to make repairs.
That’s why it’s important not to waste refrigerants due to leaking lines and coils. Service technicians need to look for leaks in older equipment so they can reclaim it and recycle it.
Overview of refrigerant leak detection tools and methods
Old school methods
Sounds and smells. In years past, service technicians relied on listening for hissing sounds, or detecting chemical smells. In some cases, you might even spot a visible oil leak. You might get lucky and notice one of these signs when working on equipment. However, none of these methods is reliable. Refrigerant leaks, especially the small ones, often make no noise and produce no detectable odor. Plus, these symptoms might not help you find the precise location of the leak.
The soap bubble method. This was the go-to refrigeration leak detection method for decades. You simply spray the line and/or coil with soapy water and look for bubbles where the refrigerant gas is leaking out. Pretty smart and it actually does work. Unfortunately, it’s not always reliable either, especially for small leaks. Plus, it makes a mess with the soapy liquid that you have to clean up.
Analog leak detectors
These were the first type of refrigerant leak detector tools. They have a thin metal rod that has a small amount of liquid nitrogen inside. As you pass the rod over the refrigerant line, any leaking gas turns the nitrogen solid which produces a sound or vibration from the rod.
Electronic refrigerant leak detection tools
Today we have electronic tools that make refrigeration leak detection more efficient and reliable. You will find a variety of electronic refrigerant leak detection tools that have different types of sensors and can accurately detect the presence and location of a leak.
The downside of these tools, of course, is the cost. However, these tools are becoming more affordable. Here are some of the commonly used types that make it much faster and easier to detect leaks:
Heated diode. These detectors use heat to break apart refrigerant molecules into chlorine and fluorine ions. When there’s a leak, the tool can detect the presence of these ions and produce an alarm. This type of tool is good at pinpointing the exact location of a small leak. However, they may need more frequent cleaning and maintenance than other types.
Ultrasonic. These devices can detect the tiny hiss of gas escaping from a pinprick hole in a line or coil, even when the sound is undetectable to human ears. The devices are also sensitive to pressure from the escaping refrigerant gas.
Infrared. These devices use infrared light, which can be absorbed by leaking refrigerant, to detect the presence of a leak. They are very accurate and less likely to produce false positives if there are other gasses present in the environment. Plus they have long-lasting sensors. The only downside is that usage is a little more tricky: you have to keep the probe moving constantly.
Here are some things to look for when purchasing an electronic refrigerant leak detector:
- A wide range of detectable gasses
- Easy to use (especially if you’re new to the industry)
- Durable construction
- 1 year warranty
- Rechargeable batteries
- Understand the maintenance that’s required
So, what’s the best refrigerant leak detection method? There’s no simple answer to that because it depends on the task and the situation. In general, however, you want a method that’s easy to use, reliable, and of course, one that works on the refrigerant you’re working with.
More HVAC & Refrigeration basics
Learn more about refrigerants and safety:
Refrigeration & HVAC Safety Tips for Technicians
HVAC Technician Certification: EPA 608 Certification Explained
Learn more about HVACR tools:
HVAC Technician Tool List: Must-Have Tools for Service
Smart HVAC Tools Make Repairs Faster & Easier
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