Propane – a natural refrigerant also known as R290 – is rapidly gaining traction in the HVAC industry. For example, Trane recently announced the launch of its Aries N and Flex N R290 chiller and heat pump ranges with capacities up to 230 kW – a first for the industry. While R290 offers excellent cooling and heating performance with very low environmental impact, it remains a highly flammable refrigerant – which is why additional safety considerations should be taken into account.

Understanding R290 Properties
R290 is one of the most environmentally friendly refrigerants currently offered on the market, mainly due to its exceptional thermodynamic properties. There are two factors which influence its popularity – while requiring special care:

• Environmental benefits: R290 has a very low Global Warming Potential (GWP) of 3 and an Ozone Depletion Potential (ODP) of 0, making it an environmentally friendly choice. Thanks to its very low toxicity, it also does not contaminate water and leaves no corrosive residues.

• Thermodynamic benefits: thanks to enhanced thermodynamic properties, chillers and heat pumps operating with R290 typically deliver higher efficiency compared to alternative HFC refrigerants, which in turn reduces running costs and indirect emissions. Moreover, the refrigerant enables wider operating maps, which increases the viability of heat pumps across different climates and applications.

• Heavier than air and flammable: In case of a leak, R290 vapor is about 1.5 times heavier than air and will accumulate in low-lying areas or enclosed spaces. Given its flammability, this accumulation, if exposed to an ignition source, poses a significant risk of combustion or explosion.

Selecting the right R290 equipment
Prioritizing safety starts with selecting the right solution provider with engineering expertise and practical know-how. Here’s what to look out for when making your product selection:

• Robust component design and enclosures: ensure your chiller or heat pump components are non-sparking compliant and that the compressor is housed in a dedicated enclosure with a leak detection system. Electrical boxes should be sealed and protected with IP54 rating.

• Leak detection and response: R290 products require additional features to minimize risk due to use of propane - but not all manufacturers offer the same level of sophistication. For example, Trane’s R290 units feature ATEX-certified leak detectors and integrated safety systems (SDS2E) for leak response. In the event refrigerant concentration is low, several preventative measures are activated, and alarms are immediately sent to external systems.

• Safety relief valves: because R290 is a relatively heavy gas, units should ideally be equipped with safety relief valves on both high- and low-pressure circuits to avoid overpressure that could lead to equipment failure or accidents. It is mandatory to convey the discharge of these valves through piping, following standards like ISO 24664.

• Local service network: Only technicians who have received specialized training for working with flammable (A3) refrigerants can service R290 equipment. HVAC providers like Trane continuously train their service technicians according to internal playbooks which are also in line with national training and certification schemes, if applicable. Choosing a provider with a local service network is critical to ensure rapid interventions.

Critical installation requirements
Once a R290 product has been selected, there are additional measures installers should take to ensure a safe and efficient operation.

• Site survey is essential: Before any installation or service, always perform a thorough site survey to identify and address potential ignition sources like open flames, light switches, electrical panels with exposed faults, pilot lights on kitchen equipment, or smoking areas;

• Ensure adequate ventilation: R290 equipment must be installed in areas with adequate airflow. Never install units in sealed rooms, tight closets, confined storage areas, or spaces that do not meet manufacturer's ventilation requirements. Proper ventilation prevents R290 from accumulating in case of a leak.

• Prevent risk of leakage: in the unlikely event of a heat exchanger failure, there is a risk of R290 leakage into the occupied space mixed with the water loop. In addition to ensuring that all units are equipped with leak detection and response systems (SDS2E), system designers should ensure that additional precautions are put in place. To avoid impacting the performance of the system, a high efficiency gas/water separator can be installed. Some manufacturers, like Trane, provide this as a factory-fitted option.

• Observe safety distances: For outdoor installations, maintaining specified safety distances is critical. Pay special attention to areas with a potentially flammable atmosphere, as well as areas where R290 could accumulate or enter buildings in the unlikely event of a leak. Avoid pathways to buildings like doors, windows, or fresh-air inlets.

• Don’t try to DIY (Do It Yourself): R290 units are engineered and certified as complete systems. Never modify the refrigeration circuit or replace components with non-approved alternatives. Unauthorized conversions of equipment designed for other refrigerants to R290 can create severe fire and performance risks. Instead, select an equipment provider with strong service capabilities and presence in your region.

In conclusion
Adopting HVAC systems with R290 is a major milestone toward decarbonizing the HVAC industry, but maximizing its environmental benefits requires a strict commitment to safety and engineering excellence.

By prioritizing smart equipment selection, following precise installation protocols, and steering clear of unauthorized modifications, you can safely unlock the high-efficiency potential of propane-based systems.

At Trane, we do not just provide cutting-edge, low-GWP factory-tested equipment, we back it up with unparalleled support. Every unit manufactured at our facility plant in Europe is thoroughly tested.

Additionally, our units are supported by the industry's widest sales and service network across Europe, Middle East, and Africa (EMEA). With more than 1,000 highly skilled, locally based service technicians, we ensure rapid deployment, minimized downtime, and complete peace of mind throughout the entire lifecycle of your system.

Contact your local Trane sales office