Development of an integrated ventilation, thermal mass, and lighting system for the first Deep Winter Greenhouse (DWG) in North Dakota

View the project final report

Commodities

• Vegetables: greens (lettuces)
• Additional Plants: ginger, herbs, native plants, trees

Practices

• Crop Production: greenhouses
• Education and Training: demonstration, farmer to farmer
• Energy: geothermal, solar energy
• Production Systems: permaculture

The project will monitor and integrate the active and passive environmental control systems of the first Deep Winter Greenhouse (DWG) built in North Dakota. DWGs are passive-solar structures with angles & dimensions that maximize solar heat during winter months, when the sun is low in the sky, and minimize solar heat during summer months, when the sun is high in the sky. The project will help balance the passive components of the greenhouse, such as the innovative use of phase change materials and an underground climate-battery, with the active components of the greenhouse, such as ventilation, heating, lighting, and CO2 supplementation. Funds will be used to professionally monitor and electronically-integrate the systems so they work synergistically, instead of antagonistically; which can easily occur with these multipart, multistage systems.

This work will maximize the efficiency of the greenhouse for growing specialty crops, and  improve its use as a demonstration and educational facility. Although the function of the greenhouse is to grow crops, its primary purpose is to demonstrate the use of innovative production methods for beginning and established producers. This project will improve the utility of the greenhouse as both an educational and agricultural tool.  

1. Develop a monitoring system and integration protocol to maximize efficiency in, and between,  greenhouse heating/cooling, air exchange, humidity, CO2, and lighting systems. This includes improving the way systems work together, but also mitigating system antagonism (e.g. venting air at same time as pulling heat from thermal mass).   
2. Evaluate the effectiveness of tiles composed of phase change material in regulating the internal temperature of a passive solar greenhouse, reflecting ambient light, and acting as a durable greenhouse wall covering.
3. Evaluate the effectiveness of a Ground to Air Heat Transfer (GAHT) system in heating, cooling, and dehumidifying a passive solar greenhouse in North Dakota.