Uniclima want to shed light on the rumours of incidents with external air conditioning units and heat pumps.

Uniclima aims to refresh memories concerning the safety rules for handling refrigerants for thermodynamic systems. These rules should help protect people and property from setbacks that could result from poor handling, especially to avoid the “Diesel Effect”.

The press release published by the company on June 19, 2014, essentially aims to show the best practices that respect the regulations and procedures. Once the pressure exceeds 0.5 bar, refrigeration equipment, air conditioning and heat pumps are considered as pressure equipment.

Uniclima wants professionals to respect the requirements of Decree 99-1046 of 13 December 1999 which require the professional takes into account the following three measures:
• Stop the compressor before any intervention,
• Set the system out voltage,
• Systematically perform vacuum operation of the facility before operating the load fluid.

In the press release, it is highlighted that technician intervention must ensure that the fluid used is supplied with a certificate. He or she should therefore ensure that the refrigerants used are HFC R-134a, R-407C and R-410A.

Moreover, interventions will have to be followed by intervention certificates given to the owner of the facility. The report further states that engineers working on refrigeration equipment must keep in mind that, under certain circumstances, an explosion hazard may occur. This is what is called “diesel effect”. This physicochemical phenomenon may occur in the case of a prolonged presence of air in the cooling unit or a pressure increase in the high pressure circuit.

Uniclima in its press release says that “a compressor is designed to work with refrigerant”. In no circumstances should it be used as a pull pump.