Modelling changes to an unheated greenhouse in the Canadian subarctic to lengthen the growing season

In remote communities in Northern Canada, food is delivered by aircraft and as a result is very expensive. Food self-sufficiency would make these communities more sustainable and resilient, but the climate is not suitable for outdoor gardens. The Iqaluit Community Greenhouse (ICG) Society purchased and, for three months in a year, operates a co-operative greenhouse that allows the growing of leafy greens. Modifications to conventional greenhouse designs, such as insulation on the north walls and roof, night covers, and adding thermal mass and a vestibule, have been shown to extend the growing season in unheated greenhouses in similar cold climate areas. A computer simulation of the ICG was constructed using TRNSYS in order to quantify the effects of different greenhouse modifications on the growing season.