Analysis of microclimate in calf housing heated and ventilated by unit heater

Abstract

Temp. inside calf pens 4 x 4 m and 3 m high holding 5 calves was measured using sensors connected to a datalogger. Pens were heated by a pulsed air system with a constant flow of 500 m/h and max. power of 8860 kcal/h, using external air heated by a water-air heat exchanger. Pulsed air could therefore be heated from -15 to +39C. Interference between natural and artifical ventilation was noted. Openings designed as air outlets also acted as inlets, with a detrimental effect on air exchange. Inside temp. was always below the optimum. Warm air from the heater mixed badly with internal air, creating large temp. gradients. Heating and ventilation with the same equipment was not recommended