Climate control systems and equipment — building design, ventilation and air cleaning

Abstract

AbstractThe design of a building affects control of climate in several ways. Its thermal insulation can be impaired by inadequate thickness of insulating material, faulty installation, settling, condensation and destruction by vermin and insects. Also its design interacts with the ventilation system which must take into account not only location, size and shape of the building, but also details such as air leakage, deflection of air jets by obstructions and dimensional changes such as occur in a timber structure. In contrast, a smooth or rough surface can respectively enhance or impede the throw of a jet as required. A permeable floor in a building may help to remove sedimented dust.A ventilation system needs to be matched to the class of livestock. Systems can be classified and described, namely, glass-fibre ceiling, high-speed jet, polythene ducts, recirculation (both damper and twin fans), hybrid (two systems combined), down-jet, Udiflo tent, and automatically controlled natural ventilation. Cyclical timing of fans gives close control of very low ventilation rates for batch rearing. Kennelled accommodation needs improved control for stock and stockman.It may be possible to reduce dust by optimizing the many factors listed that predispose towards lower dust levels. An alternative solution is to use an internal air cleaner. This can be an electrostatic precipitator, a wet scrubber or a dry filter. The latter appears to be the most appropriate and a design that discharges filtered air downwards at a speed of 0–4 m/s towards the stock has been developed and tested in a flat-deck piggery.