HOF – technology Innovative refrigeration technologies at a glance HOF has a long-standing commitment to the issues of environmental protection, climate protection and greenhouse gases. We consequently offer our plants based on conventional refrigeration technology as well as a whole range of refrigeration technologies that are based on the use of natural refrigerants. Instead of refrigerants with a high impact on the climate, such as R404A/R507A, these plants use hydrocarbons (ethane/propene), liquid nitrogen or – as in the case of our innovative HOF CryoBlizzard cold air machine – air as a refrigerant. Air as a refrigerant Using air for refrigeration offers multiple advantages. For one, air is available every- where, can be used safely and – with a GWP of 0 – does not promote climate change in any way. In addition to this, temperatures below -80 °C can easily be achieved with cold air machines such as the HOF CryoBlizzard. Legal regulations regarding the F-Gas Regulation consequently do not apply. Compression refrigeration Refrigerants such as R452A, R404A, R410A or R507A are used in conven- tional refrigeration systems, which we offer with two-stage compressors for refrigeration in the freeze drying process if requested by the customer. As known and well-tried refrigerants, these have the advantage of being non-flammable and non-toxic. They also require little space and low invest- ment costs. With respect to the F-Gas Regulation, however, some legal regulations have to be taken into account. Nitrogen as a refrigerant Our plants with liquid nitrogen as a refrigerant offer immediate cooling performance, because the -196 °C cold nitrogen is supplied directly from nitrogen tanks installed outdoors. In addition to this, these plants offer easy commissioning and a future-proof design because they are not affected by new legal regulations. They also impress with low mainte- nance costs while offering a high level of temperature flexibility. Hydrocarbons as a refrigerant Our two-stage CAR6 cascade system allows us to achieve low temperatures with natural refrigerants. The refrigerants used are the hydrocarbons ethane and propene, which allow a very high level of efficiency to be achieved with maximum flexibility. The cascade systems ensure safe operation of a plant which is also future-proof.