Statutory F-gas Leak tests – Are they still required?

Heat pumps, air conditioning and refrigeration units containing fluorinated gases have come under the EU regulation No 517/2014 since 1^st January 2015. The regulation provides specific requirements for owners of such equipment and service technicians with a responsibility to carry out leak tests depending on how much refrigerant the equipment contains.

Since the UK has left the EU, from 1^st January 2021 this regulation no longer applies to the UK. Does this mean we don’t have to follow the requirements for leak testing? In a word,  No.

Leak Tests are still required under the new (amendment) regulation

The UK has new legislation in force called The Ozone-Depleting Substances and Fluorinated Greenhouse Gases (Amendment Etc) (EU Exit) Regulations 2019 which is an amendment of the EU regulation No 517/2014 and The Ozone-Depleting Substances Regulations 2015. This regulation has adopted the same leak testing requirements for equipment containing fluorinated gases (F-gases). So basically, nothing has changed with regards to leak testing requirements.

So, what are the requirements? All operators (aka owners) of stationary refrigeration, air conditioning and heat pump equipment containing F-gases “must take measures that are technically and economically feasible to minimise leakage”. Where leaks are detected operators must carry out repairs to stop the leak without delay. Any contractors carrying out service for the operator are under a similar obligation.

In addition to this, mandatory leak checks are required, dependent on a calculated tonnes of CO² equivalent contained by the equipment. The table below explains the thresholds as well as the effective quantity of refrigerant over which regular leak checking is required.

As you can see, depending on which refrigerant the system contains, the mandatory leak check threshold will be different. There should be a label on the equipment stating what refrigerant it contains and the quantity. If it was installed after January 2017, the label should state the CO² equivalent value as well. Calculating the CO² equivalent is fairly straight forward. Simply multiply the quantity of refrigerant in kg by the refrigerant Global Warming Potential (GWP) and this will give the CO² equivalent in tonnes. If you can’t find a label or struggle to clarify if your system requires a leak test, a knowledgeable service contractor will be able to help. How though should such statutory leak tests be done?

How to carry out a leak test

There are a number of ways that a leak check can be done, but these fall into 2 basic categories:  indirect and direct leak checks. The regulation states:

“The decision on the measuring method to be used should be taken by certified personnel who have the necessary training and experience to determine the most appropriate measuring method on a case by case basis.”

COMMISSION REGULATION (EC) No 1516/2007 Point 6

Indirect methods include analysing the system temperature, pressures, compressor current, liquid levels and actual volume of refrigerant and comparing this with manufacturer or commissioning data.

Direct methods include check of components using an electronic leak detector; injecting dye and using an ultra violet light detector; or basic leak spray solution on joints and components.

Only after a leak is suspected using one of these methods should a nitrogen pressure test be carried out.

Some might believe that this is just a meaningless exercise to tick a box that a leak check has been done. I’ve known technicians who simply glance at a unit, see no trace of oil to indicate a leak and believe that they have carried out a leak check. Or they may feel the air temperature with their hands and nod that it’s cooling well so must be fine. They happily fill out an F-gas leak check log and off they go, the customer none the wiser. This is clearly not in line with the regulation and technicians and companies who employ them risk losing customers at the very least or fines if found out.

To carry out a meaningful leak check may seem like a very time consuming exercise, but it doesn’t have to be. I personally prefer to use a combination of both indirect and direct checking when carrying out leak checks and, in fact, it is best practice to do so. Here is the method I use for most air conditioning / refrigeration units. This is an example of one way to do it and I’m not saying it’s the only way or even the best way, but I’ve found it to be effective:

1. When carrying out a service on any system, whether it’s within the threshold of requiring a leak check or not, I would monitor the operating temperatures and compare this to expected operating temperatures. This is the first indirect method used.
2. If the system has fixed pressure indicators, I’d check those as well for lower than normal pressures, but I would avoid connecting to a system using my own pressure gauges unless their is a strong suspicion of a leak and I want final confirmation. This is another indirect method.
3. If a system has a sight glass, it’s worth checking that too. A low level could indicate a shortage of refrigerant, but a technician needs to be careful with this method of checking as there are other performance issues that can cause a low liquid level.
4. Next, if the system requires a leak test or I suspect it’s lost refrigerant, I would get my electronic detector out and check the usual suspects. These are mechanical joints, seals and valves. I even run the detector over the air outlets to pick up whether the heat exchanger coil is leaking – and yes, I have found leaks this way.
5. If I can’t find a leak using the leak detector but still strongly suspect that the system has leaked, the final step that will really confirm this is to recover all the refrigerant into a reclaim bottle, weigh it and compare this to the specified refrigerant charge. If it’s lower then it probably has a leak. This is a costly exercise so I would only do this if there is a real problem and confirmation is required and authorised by the owner.

Points 1 to 4 don’t take very long to perform – only about 5 – 10 minutes for a standard split unit. VRFs and other systems that have multiple connections will obviously take longer.

A note on electronic leak detectors: A lot of refrigeration engineers say that these are inaccurate and don’t use them. I must say that I once felt this way. The first electronic detector I used 21 years ago seemed to constantly alarm when there was no leak and not go off when there was a leak. I have since changed my view of them. I’ve used a Javac Tek-Mate for around 8 years now and I’ll swear by it. I’ve found so many leaks using this tool, I believe it’s indispensable. It must be calibrated every year though to be sure it complies with the regulation. Calibration costs about £45 although you do have to send it off and be without for 3 weeks.

Frostair Controlled Cooling and Heating include statutory leak checking in all our service contracts. We are an F-gas registered business and fully compliant with the current F gas certification and training requirements. We will carry out the checks and provide our customers with the mandatory F gas record. This gives our customers peace of mind that they are complying with the regulations and are getting a good service that will keep their systems running smoothly.