AIR CONDITIONING, COOLING & REFRIGERATION


Site category Access area


Maximum R-454C filling quantity per circle re- gardless of room volume


I II


a, b & c c (number of person <1/10m2) a


~11kg 50kg III


b & c c (number of person <1/10m2) all


~11kg 25kg unlimited


the use of high quality, non-detachable pipe connections, a thorough pressure test and regular leak checks. Furthermore, all materials used must be approved for use with R454C to prevent corrosion and material deterioration. To minimise the risk of fire, explosion proof electronic components should be used where possible and potential ignition sources should be shielded structurally. This can be achieved, for example, by extending the sealing of the electrical box or by limiting the maximum surface temperature of the electric heater. The surface temperature of the heater should always be 100K lower than the ignition temperature of the refrigerant, while comprehensive equipotential bonding is required to prevent electrostatic discharges. Regardless of room volume and safety measures, there are limits for the R454C filling quantity per cooling circuit. These limits depend on the category of the installation site and the type of access area: (See table above)


Category of the installation site


I. Mechanical equipment in areas where people are present


unlimited


IV all


~57kg


II. Compressor in the machine room or outdoors


III. Complete refrigeration machine in the machine room or outdoors


IV. Ventilated enclosure Type of access area


a. General access area b. Monitored access area c. Access area for authorised personnel


A step in the right direction


The aim of F-Gas Regulation 2024/573 is to tighten the phase down schedule for HFCs and promote the use of climate friendly and future proof A2L alternatives like R454C. Although some data centre operators will be concerned about switching to a refrigerant that is flammable, our R454C-based air conditioning units such as the CyberAir series at STULZ are designed to be as safe as conventional units that use non-flammable refrigerants. By supporting the use of R454C refrigerant, STULZ is continuing its mission to help data center operators strengthen their environmental credentials.


Your safety, our priority.


Carbon Monoxide & Heat


Smoke Heat Carbon Monoxide Smoke & Heat


5YRWarranty Espire® offers a comprehensive range of fire safety products, which enables you to complete the project no matter how big or small.


espuk.com email: sales@espuk.com call: 01527 515150 Read the latest at: www.bsee.co.uk


BSEE April 25 AD - ESPIRE.indd 1 ESP Espire hp BSEE Apr26.indd 1


11/03/2025 14:21 9/3/26 11:53


BUILDING SERVICES & ENVIRONMENTAL ENGINEER APRIL 2026 13


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