Strategies to reduce the apparent heat-stress indices inside a growing pig building were
compared. Two fogging strategies were studied, fogging with the necessary water
evaporating to give the same: (i) duration of heat-stress, ‘FDuration’, and (ii) intensity of
heat-stress, ‘FIntensity’, as when using evaporative pads, ‘EPads’. For the whole 5-month period
(May–September) under Greek summer conditions strategy ‘FIntensity’ was significantly
better than strategy ‘FDuration’ in terms of heat-stress duration (Po0.05; reduction 45.1%) and
heat-stress intensity (Po0.01; reduction 70.7%). Also, during the hottest day (Julian 176) it
resulted in: (i) a lower daily average inside temperature (28.5 vs. 31.8 1C; reduction 10.4%),
(ii) a smaller daily inside dry-bulb temperature variation (8.7 vs. 10.3 1C; reduction 15.5%)
and (iii) a higher reduction of peak outside temperature (36.8 1C at 14:00 h), namely 2.9 vs.
0.2 1C, respectively. For both strategies and heat-stress indices July was the most stressful
month and May the mildest. In areas characterised by high outside temperatures and
scarce water resources strategy ‘FIntensity’ should be implemented with caution as larger
water quantities, in comparison to strategy ‘FDuration’, need to evaporate.