A fixed refrigerant leak detection system continuously monitors the space around refrigerant-containing equipment, detects a leak automatically at a defined concentration threshold, and triggers alarm and ventilation outputs. Under Regulation (EU) 2024/573, installation is mandatory for stationary equipment containing 500 tonnes of CO₂ equivalent or more.
A fixed refrigerant leak detection system is no longer an optional safety upgrade for large stationary cooling plant. Regulation (EU) 2024/573, in force since 11 March 2024, requires operators to install one on stationary equipment holding 500 tonnes of CO₂ equivalent or more (Art. 6).
Below that threshold it remains voluntary — but where a system is installed, the mandatory leak-check interval doubles at every tier. The system is therefore both a compliance obligation and a way to lighten the maintenance calendar.
This guide opens a nine-part technical series: how the threshold is calculated, who falls in scope, what the system consists of, what installation and annual testing involve, and how one national implementation — Türkiye — applies the same logic with one structural difference.
- What a fixed refrigerant leak detection system is
- What the EU Regulation requires
- How the 500 tCO₂e threshold is calculated
- Leak check intervals and why a fixed system changes them
- A national implementation example: Türkiye
- System components: sensors to exhaust fan
- Installation, commissioning and annual functionality testing
- Step-by-step compliance sequence
- Frequently asked questions
What Is a Fixed Refrigerant Leak Detection System?
It is a permanently installed monitoring assembly consisting of ambient sensors, a central control unit, audible and visual alarm devices, and output relays that drive emergency ventilation and building management system (BMS) signalling. Unlike a handheld detector, it measures continuously and acts without human presence.
It works in three layers. Detection: sensors measure refrigerant concentration in ppm. Evaluation: the control unit compares the signal against pre-set thresholds and sets the alarm stage. Action: sirens, beacons, exhaust fans and BMS outputs are triggered when a threshold is crossed.
The distinction matters for compliance. A handheld detector is the instrument used to perform a periodic leak check; a fixed system is infrastructure that changes how often that check is required. The two are complementary, not interchangeable.
What the EU Regulation Requires
Regulation (EU) 2024/573 sets a 5 tCO₂e threshold for mandatory periodic leak checking and a 500 tCO₂e threshold for mandatory installation of a leak detection system (Art. 6). Where a system is installed, it must itself undergo a functionality check at least once every 12 months (Art. 6(3)).
The obligation sits with the operator — the natural or legal person exercising actual technical control over the equipment — and cannot be transferred to a contractor. The contractor performs the work; the operator remains accountable for records, intervals and registration.
| Requirement | Threshold | Basis |
|---|---|---|
| Periodic leak checking | ≥ 5 tCO₂e | Reg. (EU) 2024/573 |
| Leak detection system installation | ≥ 500 tCO₂e | Art. 6 |
| Functionality check of the system | Where installed | Art. 6(3) — at least every 12 months |
| Entry into force | — | 11 March 2024 |
Scroll the table horizontally to see all columns.
How the 500 tCO₂e Threshold Is Calculated
The threshold is not measured in kilograms of refrigerant but in the climate impact of that charge. Two systems holding identical mass can fall on opposite sides of the threshold if they use refrigerants with different global warming potential (GWP).
The formula is:
CO₂e (tonnes) = charge (kg) × GWP ÷ 1,000
| Refrigerant | GWP | CO₂e per kg |
|---|---|---|
| R404A | 3,922 | 3.922 t |
| R410A | 2,088 | 2.088 t |
| R407C | 1,774 | 1.774 t |
| R134a | 1,430 | 1.430 t |
| R32 | 675 | 0.675 t |
Worked example. A chiller charged with 130 kg (287 lb) of R404A:
130 × 3,922 ÷ 1,000 = 509.86 tCO₂e → above 500 t, a fixed leak detection system is mandatory.
The same 130 kg charge using R32:
130 × 675 ÷ 1,000 = 87.75 tCO₂e → well below the installation threshold.
The practical conversion — the charge at which each refrigerant reaches the two thresholds:
| Refrigerant | Charge reaching 5 tCO₂e | Charge reaching 500 tCO₂e |
|---|---|---|
| R404A | ≈ 1.3 kg (2.9 lb) | ≈ 127.5 kg (281 lb) |
| R410A | ≈ 2.4 kg (5.3 lb) | ≈ 239.5 kg (528 lb) |
| R407C | ≈ 2.8 kg (6.2 lb) | ≈ 281.8 kg (621 lb) |
| R134a | ≈ 3.5 kg (7.7 lb) | ≈ 349.7 kg (771 lb) |
| R32 | ≈ 7.4 kg (16.3 lb) | ≈ 740.7 kg (1,633 lb) |
The calculation is performed per item of equipment — and, where circuits are independent, per circuit — not across a site's total inventory.
Leak Check Intervals: Why a Fixed System Changes the Schedule
Under Regulation (EU) 2024/573, equipment holding 500 tCO₂e or more without a leak detection system must be checked every three months; with a system installed, the interval extends to six months. Because a system is mandatory at that tier, the three-month interval applies only in a non-compliant state.
| CO₂ equivalent | Without leak detection system | With leak detection system |
|---|---|---|
| 5 – 50 t | Every 12 months | Every 24 months |
| 50 – 500 t | Every 6 months | Every 12 months |
| ≥ 500 t | Every 3 months | Every 6 months |
Halving the number of mandated site visits offsets part of the capital cost — but the substantive benefit is detection time. A leak found by a continuous monitor is measured in minutes; one found by a scheduled check may have been running for months.
A National Implementation Example: Türkiye
Türkiye transposed the same framework through its Regulation on Fluorinated Greenhouse Gases (Official Gazette 32693, 15 October 2024). The logic is identical, with one structural difference: there is no three-month tier, because a leak detection system is already mandatory above 500 tCO₂e.
| Topic | Türkiye (OG 32693) | EU (2024/573) |
|---|---|---|
| Leak check threshold | 5 tCO₂e | 5 tCO₂e |
| ≥ 500 t, no system | Not applicable — system mandatory | Every 3 months |
| ≥ 500 t, system installed | At least every 6 months (Art. 12/1-c) | Every 6 months |
| System installation duty | ≥ 500 tCO₂e (Art. 12/4) | ≥ 500 tCO₂e (Art. 6) |
| System functionality check | Every 12 months; 6 years for electrical switchgear (Art. 12/3) | Every 12 months (Art. 6(3)) |
| Registry | EKOMVET, under the National Environmental Information System | National registries vary |
| In force | 15 October 2024 | 11 March 2024 |
Two Turkish provisions are worth noting for anyone sourcing equipment or services from the region. Personnel performing leak checks must hold a national vocational qualification certificate (Art. 16/2), and the service provider must hold a TSE service competency certificate under TS 13905 (Art. 17/1). Both are verifiable before contracting.
System Components
A typical fixed system comprises ambient sensors, a central control unit, audible and visual alarms, an emergency exhaust fan trigger output, and a BMS communication interface over Modbus RTU or BACnet.
Sensors. Most halocarbon refrigerants are denser than air, so sensors are mounted close to floor level, typically 30–45 cm (12–18 in), near compressors, service valves, flanged joints and evaporator sections. Ammonia (R717) reverses this rule: it is lighter than air and requires high-level mounting.
Central control unit. Compares readings against thresholds, determines the alarm stage, drives relay outputs and logs events. The event log is part of the compliance evidence chain, not merely a diagnostic convenience.
Alarm devices. An internal siren and an external beacon, so staff can assess the situation before opening the door.
Emergency exhaust fan. Activated automatically at the appropriate stage. Where detection is not interlocked with ventilation, the installation warns but does not mitigate.
BMS interface. Remote visibility outside staffed hours.
Installation, Commissioning and Annual Functionality Testing
After installation, the system is commissioned and acceptance-tested, then subjected to a functionality check at least every 12 months under Art. 6(3) of Regulation (EU) 2024/573.
Commissioning covers sensor addressing, threshold configuration, mapping of relay outputs to fans and alarm devices, and verification of BMS communication.
Acceptance testing proves, with test gas, that each sensor responds, that the correct output fires at the correct stage, and that the event is logged. This report is among the first documents requested in an inspection.
Annual functionality testing verifies sensor response, threshold integrity and output actuation, and assesses calibration and replacement criteria. Results are recorded.
Not sure which of your equipment crosses the threshold?
Send us the refrigerant types and charge quantities from your equipment list. Our technical team returns the CO₂-equivalent calculation, the applicable check interval per item, and whether a fixed detection system is required.
Request an AssessmentStep-by-Step Compliance Sequence
- Build the inventory. Refrigerant type and charge (kg) per stationary unit.
- Calculate CO₂ equivalent. Charge × GWP ÷ 1,000, per item.
- Classify. Below 5 t / 5–50 t / 50–500 t / 500 t and above.
- Register the equipment in the applicable national registry.
- Survey the site for equipment above 500 tCO₂e — room volume, ventilation capacity, existing infrastructure.
- Design the system. Sensor positions, cable routing, control unit location, outputs.
- Install and commission. Set thresholds, map relay outputs.
- Acceptance-test every sensor with test gas and document it.
- Schedule leak checks at the interval applicable with a system installed.
- Schedule the annual functionality test and retain the record.
Across more than twenty years of industrial cooling work, the most frequent finding on existing installations is a detection system that was never interlocked with the exhaust fan. Sensors read correctly, the control unit alarms, the siren sounds — but the room is not ventilated. On paper the system exists; in practice its primary safety function does not.
The second is sensor height: sensors mounted at eye level, 1.5–2 m (5–6.5 ft), for maintenance convenience. Most halocarbon refrigerants settle at floor level, so a high-mounted sensor sees a significant leak only after the room has largely filled.
Both faults surface on day one if the acceptance test is done properly with test gas — which is why that test is not a formality.
Sources
- Regulation (EU) 2024/573 — eur-lex.europa.eu
- Regulation (EU) 517/2014 (repealed) — eur-lex.europa.eu
- Türkiye, Regulation on Fluorinated Greenhouse Gases (Official Gazette 32693, 15.10.2024) — resmigazete.gov.tr
- National Environmental Information System / EKOMVET — ucbs.cevre.gov.tr
- Directorate of Climate Change, Republic of Türkiye — iklim.gov.tr
Frequently Asked Questions
Under Regulation (EU) 2024/573, stationary refrigeration, air-conditioning and heat pump equipment containing 500 tonnes of CO₂ equivalent or more requires an installed leak detection system (Art. 6). The threshold is based on CO₂ equivalent, not refrigerant mass, so a small system charged with a high-GWP refrigerant such as R404A can exceed it while a much larger R32 system does not. Each item is assessed individually.
Multiply the charge in kilograms by the refrigerant's GWP and divide by 1,000. A chiller holding 130 kg of R404A gives 130 × 3,922 ÷ 1,000 = 509.86 tCO₂e. The charges that reach 500 tCO₂e are approximately 127.5 kg for R404A, 239.5 kg for R410A, 281.8 kg for R407C, 349.7 kg for R134a and 740.7 kg for R32.
Yes. Intervals double at every tier when a system is installed: the 5–50 tCO₂e band moves from 12 to 24 months, the 50–500 t band from 6 to 12 months, and above 500 tCO₂e from 3 to 6 months. In practice the 3-month figure describes a non-compliant state, since installation is mandatory at that tier.
At least once every 12 months under Art. 6(3) of Regulation (EU) 2024/573. The check verifies sensor response using test gas, confirms threshold settings, and confirms that relay outputs actually actuate the connected devices — sirens, beacons and the emergency exhaust fan. Türkiye applies the same 12-month interval, with 6 years for systems on electrical switchgear (Art. 12/3).
Most halocarbon refrigerants are denser than air and accumulate at floor level, so sensors are typically mounted 30–45 cm (12–18 in) above the floor, close to the most probable leak sources: compressors, service valves, flanged joints and evaporator sections. Ammonia is the exception — lighter than air, it requires high-level mounting. Sensors should not sit in the airflow of an exhaust fan or beside a frequently opened door, as dilution delays detection.
No. The operator — the party exercising actual technical control over the equipment — remains responsible for intervals, records and registration. A contractor performs the leak check, installation or functionality test, but the obligation is not transferable. In practice, verify the contractor's certification before work begins and retain all reports directly.
Technical consultation and export enquiries
Share your equipment inventory — refrigerant types and charge quantities — and our technical team will return the CO₂-equivalent calculation, the applicable check interval per item, and whether a fixed detection system is required. Supply and technical support are available for the Middle East, North Africa, the Balkans and Central Asia.
or call directly: +90 216 344 48 19
