In modern HVAC systems, such as chillers and air-to-water heat pumps, the electrical enclosure plays a strategic role: it houses all the essential components required to control and manage the machine, from control electronics and sensors to power actuators and communication interfaces.
With the technological evolution of the sector and the increasing adoption of natural hydrocarbon-based refrigerants, such as R290 (propane gas), electrical panel design becomes even more critical. R290 is a sustainable choice thanks to its extremely low Global Warming Potential (GWP), but it also introduces new challenges related to flammability, which must be addressed with particular care.
Electrical enclosure design: reducing risk
In addition to ensuring operational continuity, the design of electrical panels for HVAC systems using R290 must meet specific safety requirements.
The primary objective is to minimize the possibility that refrigerant gas reaches critical concentrations inside the electrical enclosure, especially in the presence of electrical components that could potentially act as ignition sources.
Material selection, component compartmentalization, and proper ventilation therefore become key elements in reducing the risk of refrigerant accumulation and preventing hazardous situations.
Reference standards for HVAC systems using R290
Electrical components, both active and passive, must be designed and selected in compliance with the main industry standards, in particular:
- EN 378, which governs the safety and environmental impact of refrigeration systems;
- EN IEC 60335-2-40:2023, which defines safety requirements for heat pumps, air conditioners, and dehumidifiers.
These standards provide detailed guidance on system design, installation, and maintenance, the use of protective devices, and the segmentation of product ranges according to allowable refrigerant charge limits.
Compartmentalization and active protection systems
To further increase safety levels, it is good practice to compartmentalize high-risk areas within the electrical enclosure and integrate sensors and control algorithms capable of automatically disconnecting the power supply in the event of a refrigerant gas leak.
Relays and contactors used to manage actuators should be sealed, reducing the likelihood that gas comes into contact with critical electrical elements.
Pre-ventilation and ATEX-certified fans
In many HVAC applications using R290 propane, a pre-ventilation cycle is implemented: fans are activated a few seconds before compressor start-up to renew the air inside the electrical enclosure and remove any potential gas accumulation.
For this function, it is essential to use ATEX II 3G certified fans, made from materials designed to reduce the risk of electrostatic sparks and engineered to keep temperatures well below the refrigerant ignition point, even under blocked-rotor conditions.
Filter fans, materials, and fire behavior
When the fan is installed as part of a filter fan unit, preventing the ingress of dust and moisture into the enclosure becomes equally important. For this reason, plastic materials and structural parts must feature self-extinguishing properties, in compliance with standards such as UL 94, with a V0 rating or higher.
These solutions significantly reduce the risk of ignition or flame propagation inside the enclosure.
Emergency ventilation and alarm systems
The EN 378 standard also requires that electrical components be designed to avoid ignition sources in areas where refrigerant could accumulate. In addition, emergency ventilation measures, alarm systems, and warning signals must be implemented to enable prompt intervention in the event of an abnormal condition.
Fandis solutions for HVAC systems with flammable refrigerants
To meet these increasingly stringent requirements, Fandis offers a complete range of solutions for the ventilation and thermal management of electrical enclosures used in HVAC systems with R290 propane refrigerant.
The range includes ATEX-certified fans, equipped with alarm and/or tachometric signals, specifically designed for applications involving flammable refrigerants. These solutions combine safety, reliability, and regulatory compliance, supporting manufacturers and designers in developing sustainable and safe HVAC systems.
Learn more about Fandis solutions for the HVAC sector and natural refrigerant management by visiting our website or contacting our technical team.