Indoor Agriculture Systems

Indoor agriculture can be an energy-intensive operation. During the “daytime” mode when grow lights are on, indoor agriculture HVAC systems must provide enough cooling to offset the sensible loads (likely from grow lights and some envelope loads). At the same time, the systems must also offset the space latent loads from plant evapotranspiration which requires dehumidification.

To maintain space temperature and humidity for indoor farms, indoor agriculture HVAC systems will very likely need to be equipped with both temperature and humidity control.

During the “nighttime” mode when grow lights are turned off, systems often need to provide dehumidification to offset some space latent loads from the plants, but there is little sensible cooling to offset. In fact, there may be times when the space requires both dehumidification to offset the plant’s water vapor contribution and heat to offset the cooling effect from the plants. 

When dealing with commercial grow rooms or indoor farming, several HVAC considerations arise. Plants need a variety of nutrients, minerals, vitamins, water, carbon dioxide, and oxygen. A system or enterprise control system can be used to integrate lighting, irrigation, fertilization, and HVAC operation.

The procedure for determining the proper supply air conditions—dry bulb temperature and humidity ratio— may be different due to the fact that the load can be dominated by plant latent loads. As a result, the proper supply air conditions may not conform to traditional comfort cooling methods. HVAC design and analysis tools, like TRACE® 3D Plus™ can help with this.

The use of a controlled environment permits the growers and operators to determine when plants are illuminated for the “daytime” period when grow lights are on. In those buildings with multiple, separated growing spaces, operators may consider staggering the “daytime” periods for several reasons including reduced peak load, electrical demand and load swings.

Air filtration helps HVAC components remain relatively clean and helps keep foreign contaminants and particles out of the growing environment.