Carbon Efficient Cooling at Clarks

The cooling of two large mezzanine floors at the Clarks Shoes warehouse in Somerset has been accomplished using innovative evaporative coolers. A total of 12 coolers, providing up to 400KW of cooling capacity, were installed as part of a cross flow ventilation scheme. Because of increased demand and expansion overseas, Clarks has built a new distribution centre at its Somerset HQ. This is housed in a building of gigantic dimensions: 188m long by 152m wide and up to 18.5m high. It covers an area equivalent to six football pitches and Clarks says the building is big enough to squeeze in the entire population of south-west England. The warehouse has the capacity for six million pairs of shoes and is designed for a daily throughput of 200,000 pairs. Two mezzanine floors totaling 11,000m2 form the main picking area and operating conditions here were proving uncomfortable for personnel. Barry Mosley, Clarks Group Facilities Manager required an environmentally friendly and low cost solution to the cooling of this area. "Clarks has a strong environmental ethos whilst still requiring commercially sound investments. Evaporative cooling has only 15% of the carbon impact compared with conventional refrigeration based air conditioning and in addition the coolers do not use potentially harmful refrigerants'. The top discharge coolers were installed in four banks of three to feed the two mezzanine levels. The five speed units can run in either ventilation or cooling modes. Each cooler is controlled by a combined Hygro-thermostat, which automatically sets the fan speed and the cooling mode. The system is linked to the fire alarm system to provide automatic shut down in the case of emergency.