Smart Glazing for Energy- and Cost-Efficient Greenhouse Humidity Regulation

Global food shortage demands significant progress in crop production. Greenhouses offer a solution for higher crop production by providing a controllable environment. Excess levels of humidity, however, encourage pests and diseases, drastically reducing crop yields. Traditional humidity control methods for greenhouses are expensive and energy-intensive. In addition to this, nonbiodegradable plastic covers cause massive white pollution. To tackle these concerns, we present smart glazing and sensors for greenhouse humidity regulation through both passive and active paths. We created biodegradable humidity-sensitive films by blending poly(ethylene glycol) (PEG) with cellulose acetate (CA). PEG/CA covers can automatically open for air circulation at high humidity, successfully demonstrating repeatable greenhouse humidity regulation to as low as 60% relative humidity. PEG/CA-based humidity sensors can actively accelerate air circulation and humidity reduction with repeated cycles at an even higher efficiency. Overall, our research introduces a low-cost, all-in-one, sustainable, and environmentally conscious solution for addressing the greenhouse humidity control challenges. Approximately, this solution can potentially achieve annual energy savings of up to 56.6 GWh for the U.S. if fully applied.