Modification of the environment by animal houses in a hot humid climate

A survey was conducted in West Java to study the modification of the environment by traditional sheep and goat houses. The houses were all small and had a thick sloping roof with large overhangs, slatted walls and a slatted floor raised an average of 0.6 m above the ground. The mean wind speed outside the houses was low (0.3 m s⁻¹) and on average the wind speed inside the houses was 37% of that outside. The mean temperature outside the houses was 21°C in the morning and 27°C in the afternoon. The corresponding relative humidities were 93 and 70%. The internal temperature was only 0.3°C higher than the external temperature on average and the internal humidity only 0.3 g m⁻³ higher than the external humidity, indicating that in general the houses were well designed to maintain the internal environment as cool and dry as possible. Comparisons between houses showed that a high internal wind speed, a low number of animals per unit area and a long roof overhang favoured a low internal temperature. Houses with higher platforms and more open walls had higher internal wind speeds than lower, more enclosed houses. Heat losses from the animals in the houses by long-wave radiation and evaporation were larger than the heat losses by convection.