OSV delivered two explosion proof combined air conditioning / pressurizing units for offshore Thailand during March 2009. These units are to be used to air condition and pressurize a switchgear room and an emergency shelter. Each unit is a single self contained package which is designed to cool and pressurize the rooms using 100% fresh air. Units are arranged as duty and 100% standby. Each aircon unit contains two separate and independent 50% aircon systems. The systems provide control of both temperature and humidity.
The combined aircon/pressurising unit specification includes:-
- Unit suitable to operate in a Class 1 Division 2 Group D hazardous area.
- Unit frames of 316L stainless steel.
- Evaporator and condenser coils to have copper fins and copper tubes with a coating to inhibit corrosion.
- R407C refrigerant
Each unit has three Siemens Logo PLCs housed within the Exd enclosure. One PLC controls the pressurizing fan system and two PLCs control the airconditioning systems. The Siemens PLCs are controlled by an Allen Bradley PLC in a master HVAC control panel which controls the whole HVAC system and communicates with the platform SCADA system. The master HVAC control panel was also designed and fabricated by OSV and programming of both Siemens and Allen Bardley PLCs was by OSV.
The cooling performance for each unit is 27kW.
OSV also provided the design of HVAC system and all other HVAC components including exproof split aircon units, fire dampers, pressurizing dampers, grilles and cowls, differential pressure switches, external ducting, room temperature controllers and Exd control panels.
OSV specialize in designing and building HVAC systems for areas classified as hazardous such as offshore oil and gas platfoms and analyzer houses.
