A system for reducing the refrigerant pressure in an oil sump (10) or in a cavity (352) of a housing. The invention is particularly useful for reducing pressure in a compressor (23) for heat pump applications that has been validated for water chiller operations or in turbine and generator systems in ORC systems generating electricity using refrigerant, the ORC systems essentially being a heat pump application operating in reverse. An auxiliary compressor (509), an auxiliary condenser (709) or an ejector pump (609) may be used to reduce pressure in the oil sump (10), to separate refrigerant from oil. The auxiliary compressor (509), the auxiliary condenser (709) or the ejector pump (609) may also be used to reduce the pressure of refrigerant in the housing of a compressor in heat pump applications at temperatures and pressures at which the compressor was validated for water chiller applications and of the turbine and generator in ORC applications.