Refrigerant Leak Detector

Refrigerants leak from HVAC systems due to the deterioration of joints, fittings, or parts that are welded, which become faulty with time. Leaks might be low as 1 oz every few years, but also might be much greater, such as a few ounces per day. Losing refrigerant means compromised performance of an AC cooling system, as well as greater expenses.

Measuring refrigerant leaks is important from two points of view: economic loss and environmental pollution. EPA rules mandate proper practices in refrigerant leak detection and you want to ensure compliance with these regulations.

What methods do are used to find leaks in HVAC AC cooling systems?

Traditionally, an HVAC service tech would use the soap bubble test, a visible method to detect leaks of any refrigerant. However, this method is not the most accurate and is difficult to implement in hard-to-reach places.

Another method, using a fluorescent dye, is also a visible way to see leaks. It works with any refrigerant; however, a dye must be added to the system, and a special UV light be used in the inspection. Again, inspection of leaks in hard-to-reach places is difficult to perform.

Currently, the most popular method is facilitated by the use of electronic leak detectors. This method is the most accurate; however, one must remember to monitor the sensor’s condition as well as calibrate the instrument periodically.

What are a types of electronic leak detectors?

Corona discharge is one of the most traditional types. In this method, air with gases passes through an electrical field around an electrode and an electric arc (discharge) breaks down refrigerants, which are detected by a sensor and “reported” with an alarm signal (sound).

Heated diode is a second popular type in which a heater close to a diode breaks down gases, yielding a change in current flow through diode. Such a change triggers the alarm resulting in audible leak detection.

In the heated electrolyte method gases are broken down as they go over electrolytic material in the sensor. Again, the resulting change of current flow triggers the audible alarm.

Sensors using corona discharge, heated diode, or heated electrolyte detectors need to be changed quite often, so proper monitoring of their use is necessary.

Infrared detectors are the best option, as their sensors typically last over 1000 hours - equivalent to over 5 years of use. In this method an air sample with gases passes through an optical window of a sensor and the refrigerants absorb IR radiation. An alarm gets triggered by the amount of IR radiation absorbed and carried over the sensor. This is by far the most accurate method, as it had been used in laboratory settings for many years and now is available to HVAC technicians.

Finally, there is an ultrasonic gas leak detector, one that uses sound amplification to detect leaks. Gases passing through orifices or breaks in pipes produce a high pitch sound not detectable by a human ear but easily recorded by ultrasonic leak detector. The method is great, but the main shortcoming is that very small leaks don’t produce enough sound and they might not be detectable.

Our favorite type is the infrared leak detector, due to its accuracy and low ownership cost over time. However, infrared leak detectors are expensive, so they might be out of reach for many techs beginning their carriers or some on a tight budget.

What companies are recognized as makers of quality refrigerant leak detectors?

Here is a short list of brands popular in the US: Accutools, Amprobe, Bacharach, CPS Products, Extech, Fieldpiece, General Tools, Inficon, JB Industries, Mastercool, Robinair, Supco, TIF Instruments, Testo, TPI, UEi, and Yellow Jackets.

Value Testers is an authorized distributor of many brands. If you prefer to purchase a product made in US, ask us which manufacturers do so and we will help you make the best selection.