Discover everything you need to know about the EN378 regulation, and how it affects your business' workplace and equipment here.

Ensuring your business is staying on the right side of the law is second-nature to many business owners and their teams, however there are often quite hidden legal terms in the law regarding the equipment within your workplace. Does your office, warehouse, or other working environment have an air conditioning system, or refrigeration system – or both? If you answered yes to either of these questions, we strongly suggest you take a quick read through this article to ensure your equipment is compliant.





Here at IRS, we have extensive knowledge of legislation, including F-Gas regulations, refrigerant phase out, and TM44 inspections of air conditioning; helping businesses stay compliant across the region. Our team are dedicated to continuous improvement, which is why we are pleased to be accredited and currently working to ISO9001 and ISO14001 standards. We have numerous procedures and policies in place to support customers and employees’ health and safety, and environmental requirements. You can view and download the full details of our policy documents here.

We are a Mitsubishi Electric Business Solutions Partner, which means that we have extensive knowledge and experience in ensuring refrigeration systems and heat pumps are compliant and safe. One of the main regulations is the EN378 regulation. EN378 stands for, “British Standard (European Wide)”, and it details the specification for refrigeration systems and heat pumps to meet safety and environmental requirements. The regulation dictates the maximum size of refrigeration systems, including refrigerant-based air conditioning. 


Occupancy Categories

Did you know there are a wide range of different occupancy categories? If your workplace has a refrigeration or heat pump system installed, you come into one of these categories. Wondering where EN378 comes in? The regulation dictates the maximum allowable size of the refrigeration system for the Occupancy Category of the room (and of course, they are different for each category). 

Category A – General Occupancy

Includes bedrooms, offices, hospitals, hotels, etc

Category B – Supervised Occupancy

Includes workplaces such as plantrooms, which have occasional entry by approved personnel

Category C – Authorised Occupancy

Includes workplaces such as plantrooms, where authorisation for entry is required


What does this mean?

Typical affected applications are most commonly direct systems, with an evaporator in a Category A occupied space, (hotels, restaurants, residential, offices, hospitals, etc). Since these are the most common workspaces which would likely have systems in place, we thought it would be best to let you know what EN378 compliant levels are: 

Max. allowable refrigerant concentration level – in Cat. A occupied zone:

Practical limit = 0.44kg/m³


The requirements

Since EN378 is a regulation – you have to comply to the requirements in order to become and remain compliant. These include: 

- Having Leak Detection installed and Permanently Operational in Affected Spaces

- To provide Visual and Audible alarm to alert Occupants in Affected Spaces

- To have reporting to Responsible Person at Central Point on Uninterruptible, Non Shared Network


Even more confused? Thankfully, we are trained to extremely high standards to ensure we can sort everything out for you. We don’t only like to keep ourselves compliant, but we also strive to keep our clients compliant to provide them with an easy-sailing working day – without needing to worry about whether their leak detection will kick in, or whether their system is above their maximum allowable refrigeration concentration level. We understand it can be a minefield.

You can trust us

Our dedication to improving our services and solutions is echoed in our impressive list of accreditations and certificates, which you can view here. We also pride ourselves on being health and safety astute – our memberships with Safecontractor, CHAS, SMAS, and Constructionline demonstrate this. As well as this, we also have Refcom Elite accreditations for our FGAS procedures. 

Even if you might not require our services – if you feel like you need to have a quick chat to get things clarified, or to find out if you need anything, feel free to give us a call on 01527 577999, or by completing the contact form here, and one of the friendly team will get back to you as soon as possible. 


Posted on 18/11/2019