Performance Assessment of a Closed Greenhouse in a Hot Arid Australian Climate

Abstract

Abstract In this paper, we present a validated thermal model of a greenhouse. Then summer climatic data of a location in South of Australia (Port Augusta), known to have dry and hot summer, is used to compare the potential of different cooling technologies in providing cooling to greenhouse indoor air while considering the minimization of water consumption. Several cases are examined and compared to a reference case which is a closed greenhouse without cooling. The operation cases considered for cooling purpose are 1 - Fogging system; 2 - Single pipe Earth-to-Air Heat Exchanger (EAHE); 3 - Multiple pipe EAHE; 4 - combined operation of Fogging system and EAHE. Results indicated that relying on shallow geothermal energy through an Earth-to-Air Heat Exchanger (EAHE) minimized the water consumption of the fogging system reducing it from 11.6 to 4.7 kg/day. Furthermore, the results show that cooling via EAHE is the best strategy in terms of reducing water consumption without significantly affecting the temperature reduction when compared to the water reliant cooling technology fogging system. The combined operation of EAHE and fogging system managed to keep the indoor air condition at the favorable plant cultivation temperature level (20–30°C) and relative humidity (70–80%).