A comparison in performance of greenhouses with various shapes: a parametric study

Abstract

SYNOPSIS This paper presents a comparison in the performance of greenhouses with various shapes for a composite climate (New Delhi). The shapes under study are: even span, uneven span, modified arch, vinery and modified IARI. The performance of the greenhouses has been evaluated with the help of an experimentally validated model. A parametric study has also been presented. The effect of a north wall has been numerically evaluated in an even span, uneven span and modified arch shaped greenhouse. Based on numerical computations, which were carried out for a typical day in summer and one in winter, it could be concluded that: i. greenhouse shape affects the room temperature and thermal load levelling significantly, which is higher in winter as expected; ii. The maximum room temperature (15°C and 20°C) and thermal load levelling (0.10 and 0.12) were increased due to the north wall in winter and summer conditions, respectively; iii. the fluctuations in room temperatures were reduced due to the increase in isothermal mass (water); iv. an increase in the number of air changes along with the use of movable insulation considerably reduced the room temperature in an uneven span greenhouse with a north wall and v. in terms of room temperature and thermal load levelling, the modified arch and vinery shaped greenhouses presented the best performance in summer and winter conditions, respectively.