Demonstration of energy-saving dehumidification in Ontario greenhouses (GRET)

Four dehumidification technologies were tested at three different facilities over a three year period: commercial mechanical refrigeration dehumidifier (MRD), chemical liquid desiccant dehumidifier (LDD), air-to-air heat recovery ventilation system (HRV), and finally a prototype called energy recovery ventilation (ERV), which is a combination of liquid desiccant approach (wet mode) and an air-to-air heat exchanger (dry mode). Overall, energy savings could be achieved, but the dehumidification systems controls needed. to be strategically integrated in the greenhouse computer control system logic in a manner that resulted in optimal performance in order for the savings to be significant. A method for in-house qir quality monitoring was developed using 3M Petrifilms, and showed a linear correlation with standard air quality testing methods.

York Region Water Reuse Research and Demonstration Project

The Water Reuse Research Demonstration Project evaluated the effects of the use of reclaimed treated municipal water as an irrigation source for sod production on plant health, soil properties, and surface water and groundwater quality. An on-farm assessment was conducted that followed the soil (detailed soil cores to 60cm), water (lysimeters, nested groundwater wells, and tile water) and crop (plant health, germination and alternate crop) effects of over the 2018 and 2019 growing seasons, on replicated test and control plots. Both treatment and control areas were managed identically with the exception of the irrigation water source: control (irrigation pond water) and treatment (reclaimed water from the Regional Municipality of York).

Best Management Practices for the Ontario Greenhouse and Container Nursery Industry to Protect Surface and Sub-surface Water Quality TOGA-OMAFRA Great Lakes Project 07-038)

The project objectives were to demonstrate the principles of collection, treatment, and reuse of irrigation runoff water in the greenhouse horticulture industry and develop and draft a. Existing treatment systems were monitored at three sites and new systems were installed and monitored at the seven sites. Irrigation water runoff and water at interim stages of each treatment system were monitored to determine their effectiveness. A Greenhouse and Container Nursery Water and Nutrient Management BMP document was drafted which formed the basis of the three individual OMAFRA BMP and self-assessment guides for greenhouse vegetable, container nursery, and greenhouse floriculture production.