Greenhouse growers across the USA are being advised to take note of new rules for protected crops growers in California since the state amended its building energy code to include controlled environment horticulture (CEH) in its mandatory requirements, a first for the country.
The code was initially produced in the 1970s and is updated every three years. The latest update for non residential buildings, which came into effect in January, now demands newly constructed greenhouses and indoor facilities such as vertical farms, or those being retrofitted, to meet standards for horticultural lighting efficiency, lighting controls, HVAC equipment and glazing. For instance, lighting must have a PPE of 1.7mmol/joule for greenhouses and 1.9mmol/joule for indoor growing. Greenhouses must be double glazed as a minimum.
Experts say that modern HPS and most LED lighting will comply with the code but the state is already working on the next update, to be implemented in 2025, which will explore increasing the PPE lighting threshold and introducing mandatory environmental and irrigation controls.
The measures were prompted mainly because of the recent and sudden increase in energy use for the licensed production of cannabis following changes to cannabis legislation.