Experimental investigation and modelling of thermal environment control of air distribution systems for chilled food manufacturing facilities

Abstract

Chilled food manufacturing facilities in the majority of cases have high ceilings to allow flexibility for the accommodation of different height equipment and manufacturing lines. The facilities are normally cooled by fan coil units located at ceiling level in a similar way to cold rooms, resulting in high velocities, uncomfortable environments for the workers and high energy consumption. To address these issues, this paper investigates the influence of different air distribution arrangements on air velocities and temperatures in a laboratory scale test facility and by means of a CFD model. The objective was to achieve low velocities and uniform temperatures at low level to achieve temperature stratification between floor and ceiling levels to reduce energy consumption. Experimental and CFD modelling results agreed that supplying air at medium level in the space through fabric ducts ‘socks’ could provide temperature stratification of the order of 7 C between floor and ceiling level and energy savings in the region of 9% compared to ceiling mounted fabric ducts and 23% over non-ducted cooling coils mounted at ceiling level.