R-290: Propane as a refrigerant
This article gives operators of refrigeration, air conditioning and heat pump equipment charged with R-290 a quick overview of R-290. It also contains useful information on R-290 as a possible alternative refrigerant for operators of systems filled with refrigerants that are subject to volume restrictions or future bans as under the European F-Gas Regulation. It explains where to obtain further information and assistance as well.
General information about R-290
Propane (molecular formula: C₃H₈) is a hydrocarbon that exists as a colorless, odorless gas. This natural refrigerant is also named R-290. It has comparable working pressure levels and refrigeration performance to conventional refrigerants. R-290 has been used in refrigeration, air-conditioning and heat pump equipment for years, and its use is on the rise.
R-290 is valued as a high-performing, energy-saving refrigerant due to its high energy efficiency and excellent thermodynamic and refrigeration properties, which are comparable to R-22, a formerly widely used refrigerant. It is not ozone-depleting and its low GWP (global warming potential) value of 3 means it has a very low greenhouse effect. Consequently, this makes the liquefied gas an environmentally friendly alternative solution that can circumvent future use restrictions and bans on fluorinated refrigerants (F-gases) in quite a few applications.
Propane does have one problem as a refrigerant: It is highly flammable. Its use is thus subject to special safety requirements. In addition, it can form explosive mixtures when mixed with air, but propane is very unlikely to escape into the air if proper safety precautions are taken.
R-290: an alternative to F-gases
The phase-down required by the current EU F-Gas Regulation and the associated use restrictions and bans have already caused a noticeable shortage of many common high-GWP refrigerants. This has drastically increased prices. Obviously, these developments pave the way for less climate-damaging solutions in refrigeration and air conditioning. The refrigerants of the future include natural refrigerants such as propane, butane and other hydrocarbons; ammonia; and carbon dioxide (CO₂ solutions).
R-290 is a particularly suitable replacement for R-502 and R-22; it has very similar thermodynamic properties to R-22 and can basically be used wherever R-22 was previously used. In many cases, only minor technical adjustments were required when converting from R-22 to propane.
In all cases, operators saw better operating performance and energy savings of 10 to 30 percent. However, system retrofits should always consider the safety requirements of using a flammable refrigerant, including risk assessments and safety modifications (explosion protection, installation site, etc.) where applicable. Propane can also easily substitute for R-134a, R-404a and other comparable substances under certain circumstances. Operators found average energy savings of about nine percent over the same systems using R-134a.
The use of R-290 or an R-290 retrofit in commercial refrigeration and air-conditioning equipment can be subsidized by the German Federal Ministry of the Environment.