Roche Products / U.K.

Planning / Implementation / Main components

Star Refrigeration Ltd.

Refrigerant

Ammonia (NH₃) / Hydrocarbon C₃H₃

System start-up

2005

Roche Products, a global health care company, was looking for a sustainable solution for air-conditioning the office spaces at its Welwyn Garden City headquarters just north of London. Star Refrigeration designed an office air-conditioning system that uses very little energy.

Demands

A system that would provide environmentally friendly, efficient air-conditioning for a modern, nearly 22,000 m³ office building was needed.

Solution

Star Refrigeration installed two 930 kilowatts ammonia chillers on the roof of the building. This allows the condensers to be cooled by the outside temperature, which additionally boosts the system’s effectiveness. Three of the chillers run on hydrocarbon and cool just the server rooms. Each of them has a refrigeration output of 130 kilowatts.

Type of facility

Liquid chillers

Refrigerant

NH3 / C3H3

Refrigerant volume

200 kg NH3 / 13 kg C3H6 per chiller

Refrigerant

Cold water

Refrigerating capacity

2 x 930 kW / 3 x 130 kW

Main components

2 NH3 chillers, 3 C3H3 chillers, condensers

Special features / Comments

All five cooling units are equipped with sensors to monitor leak tightness, along with an alarm system. A computer-based monitoring system ensures the system’s reliability and operational readiness. Its environmental friendliness and low greenhouse gas emissions earned the refrigeration system the RAC Cooling Industry Award 2005 for “Installation of the Year – Commercial.”