HYDROCARBONS

Isobutane (R-600a) has become the standard refrigerant in new appliances in many markets. In small quantities used in the appliance, do not constitute a significant risk, after the change of design of refrigerators, where all the switches (e.g. thermostats lights and switches were removed from the refrigerated compartment. Leak into the room where the unit is placed disperse and not result in dangerous concentrations.

Propane (R-290) and Propylene (R-1270) more appropriate properties for replacement of R-22. Several hydrocarbon mixtures were also presented as replacements for CFCs and HCFCs. In several markets of hydrocarbons have been used in small commercial холодильное equipment and air coolers.

Safe use of hydrocarbon requires training of persons involved in the design, installation and servicing equipment. Standards and regulations adapted for use in RAC systems are important to avoid the impact of technical experts and users at risk due to the irresponsible practices.

Today there are international standards for products, which cover small sealed systems (having a charge of less than about 150 grams), which allows them to be installed in most places, provided that proper design precautions have been taken. For larger systems, standards, see "relevant national and international standards i.e. EN378 and ISO 5149" (GTZ-Proklima, 2008).

If the charge of hydrocarbons may be lower than the volume of air in the room (usually 8 g/m3) the risk of a flammable mixture is excluded. Compatibility oils in connection with hydrocarbons is sometimes overlooked issue, since high levels of compatibility caused numerous failures of the system, when hydrocarbons have been introduced without adequate reconstruction.

This report will not discuss the modernization of existing HCFC systems for oil and gas, as an estimation of the old unit designed and located, without regard refrigerant Flammability in the most difficult cases, and must be done in accordance with international as well as national legislation. We can say that there is obviously much less risk involved in systems with charge below, which can create an explosive environment in the room or if the whole cooling system is located outside i.e.. air cooled chillers. Information about the design of hydrocarbon systems presented here will be relevant in connection with the consideration when hydrocarbons are used, but additional requirements will often apply. Safety related to the operation, and maintenance must always be carefully considered before flammable refrigerant applies...