Why Central Air VRV/VRF slow conversion from Gas R-410a sang Gas R-32? While the civil air-conditioning (wall-mounted) has moved to R-32 For a long time, high-power central air-conditioning systems like VRV (Daikin) hay VRF (Mitsubishi, Panasonic…) is much slower.
The reason lies not in refrigeration technology, but in the following strict technical and safety barriers:
1. Flammability properties (Group A2L)
R-32 belongs to the gas group A2L (a little flammable).
- With air conditioning wall-mounted: The gas intake is low (usually below 1 -2kg). If there is a leak, the gas concentration in the room is unlikely to reach the level of ignition.
- With the VRV/VRF system: A central system for the building can hold up to Tens, even hundreds kg gas. If a leak occurs in a closed space (such as a hotel bedroom), the concentration R-32 will rapidly exceed the safety threshold, posing a huge risk of fire and explosion.
2. Operating pressure and pipeline
Pressure of R-32 is higher than that of R-410A.
- The VRV/VRF system has very long gas pipelines (up to hundreds of meters) and multiple junctions.
- The control of leakage and high pressure on such a massive system is much more complicated than on a single air-conditioning unit. Standards for copper pipe thickness and protective equipment must be changed completely.
3. Construction and Fire Prevention and Fighting (Fire Prevention and Fighting) Regulations
Safety laws and standards in many countries (including Vietnam) have very strict regulations on how much flammable refrigerant is allowed to be charged in a closed system of a building.
- To use R-32 for VRV, the manufacturers must install additional gas leak sensor and automatic stop valve at each indoor unitThis is driving the installation costs up dramatically, which R-32 It loses its competitive edge on price.
4. The "Thermal Water" Effect and Lubricants
Although R-32 is monodisperse (easy to load extra), compatibility with high-power compressor inverter lines of VRV/VRF requires special lubricating oils. The redesign of the entire compressor system and heat-exchange array for R-32 optimization at an industrial scale requires a lot of endurance testing time (typically 5 -10 years).
5. Current situation
Slowly, but moving, the movement is beginning to take place:
- Daikin launched line VRV 5 in some markets (such as Europe) using R-32 but accompanied by extremely sophisticated leak control systems.
- Intermediate solutions: Many are looking at alternative gas or systems Chiller water-cooled (rinsing cold water in the room instead of direct gas) for maximum safety.
In summary: R-410A still dominates the central air - conditioning array because it absolute fire safety (Group A1)It's a great way to give investors and contractors more peace of mind when installing high-rise buildings.
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