Air Source Heat Pump Performance in Open, Semi-closed, and Closed Greenhouse Systems in the Canadian Prairies

Abstract

The specific objective of this study was to investigate regional spatiotemporal distributions and spatial correlations of energy and water consumption in open, semi-closed, and completely closed greenhouse systems in the Canadian Prairies. The findings showed that the energy and water consumptions were both spatially and system dependent. Both latitude and longitude significantly predicted total energy consumptions. Latitude significantly predicted water consumption in semi-closed and closed systems as well. Semi-closed system was the most energy conserving system, while closed system was the most water conserving. Locations at lower latitudes had higher water consumption due to increased amount of available solar radiation. Water consumptions in open systems at higher and lower latitudes approached to each other due to relatively increased transpiration rates at higher latitudes as the vapor pressure deficit became larger due to colder and drier outside air. Locations in the southwestern Prairies (Alberta, and partly Saskatchewan) had the lowest energy consumptions in all systems.