Evaluating thermal performance of experimental building solutions designed for livestock housing: the effect of greenery systems

The thermal performance of a greenhouse-type building provided with a living plant canopy was evaluated in Northern Italy during summer. Four reduced scale buildings with different types of covering were tested. The first type was the reproduction of a gable roof covered with 40 mm-thick sandwich panels (SAND), a widespread solution for dairy barns in temperate climates, used as control. Two roofs were reproductions of a Venlo-type greenhouse covered with a 0.2 mm-thick transparent EVA film equipped with either a reflective shading screen with 70% shading level (TRA+SHA) or with a living plant canopy (TRA+PLA). The last type of roof consisted of the living plant canopy alone (PLA). Plant canopies were made up of climbing plants (Trachelospermum jasminoides) with an average LAI of 1.39 m2 m-2. Data were analysed with mixed linear models for repeated measures. Fixed effects tested were roof type and the interaction of roof type and time of the day. Internal temperature in TRA+SHA (22.60 °C) was higher than PLA (21.28 °C; p > 0.001), SAND (21.53 °C; p = 0.026) and TRA+PLA (21.68 °C; p = 0.036), with no significant differences among the latter three. Differences were larger during the hottest hours of the day (from 09:00 till 17:00) while, during the night, internal temperature did not differ among types of roof. Results indicate that greenhouse-type buildings with conventional shading systems may not be adequate for housing livestock in warm climates. However, the employment of greenery systems such as a plant canopy may effectively reduce internal temperature. Further research is deserved to develop suitable building solution for livestock farming.