The Importance of Specialized HVAC Systems for Grow Rooms

Cannabis is one of the most valuable crops in North America, with over 2 million grow rooms in the United States and approximately 700 in Canada. Analysts estimate the legal cannabis market will be worth over $21 billion in 2021. The cannabis industry presents tremendous opportunities for HVAC businesses because of its enormous indoor growing area size. The grow rooms are considered critical environments and need specialized equipment to keep crops healthy, productive, and sustainable.

Cannabis- iStock-1124252622Currently, in the US, nine states allow the sale and recreational use of cannabis: Alaska, California, Colorado, Oregon, Nevada, Maine, Massachusetts, Washington, and Vermont with 30 other states having legal, medicinal cannabis programs. In 2018, Canada legalized the sale of recreational and medicinal cannabis.

As a result, cannabis is in huge demand. Growers must not only provide an adequate supply of premium cannabis but also need to comply with local regulations. This is good news for the HVAC industry because a well-designed grow room facility is essential. These facilities utilize a wide variety of equipment such as chillers, boilers, dehumidifiers, humidifiers, and controls to maintain stringent conditions of the indoor environment.

Grow Rooms
Most of the legal cannabis products are grown in climate controlled grow rooms. Rooms are custom designed to produce high yields of specific strains of cannabis. They are entirely sealed greenhouses or rooms with few windows and use unique artificial lights to stimulate plant growth. The potency of the cannabis is controlled to specific parameters versus the uncertainty of growing in an open field with the risk of insects, disease, errant crop dusters, and theft.

Specialized HVAC System
The environment of a grow room is like a jungle; it’s warm and humid, and the electronics need to be durable to withstand these conditions. Traditional HVAC systems are not able to create and maintain the optimal environment for cannabis plants because they cannot effectively control and balance air flow, humidity, and CO2 levels.

Cannabis plants are very particular about the environment that works best for them to thrive. Temperature and humidity must be able to be set within specific ranges depending upon the crop; otherwise, it could spoil the growth. Grow rooms are notorious for producing an overwhelming aroma that also needs to be managed.
The profile of these facilities are energy intensive. Not only in maintaining temperature, humidity, and airflow, the 24-hour a day specialized lighting puts out a vast amount of heat.The cooling systems needs to be able to remove the additional heat efficiently for positive growth.

The HVAC system needs to be energy efficient and able to maintain air, temperature, humidity, and CO2 levels for business success.

Newer HVAC systems are able to adjust and maintain more precise humidity levels and distribute the appropriate air evenly when needed. Belimo has worked with many indoor grow farm facility professionals and consulting engineers to enhance traditional and newer HVAC systems improving the indoor environment and system efficiencies. From changing out of pressure dependent valves, which had flow variation when upstream pressure changes, causing an unstable temperature environment, to pressure independent valves that maintain precise flow through each coil as commanded by the control signal. As a result, design conditions were met and maintained with increased energy efficiency.

With pressure independent valve technology, only a single valve is required to maintain proper flow through each circuit. Belimo’s electronic pressure independent technology uses an integrated flow sensor and a robust control algorithm combined with a control valve. The integrated control signal maintains flow set point regardless of system pressure variations with its robust algorithm that modulates the valve based on its measured true flow.


Belimo continues to retrofit many failed or ineffective temperature, humidity, CO2, and air quality sensors with Belimo sensors that work more efficiently in these demanding conditions. Higher levels of CO2 are required in these facilities, without it, plants suffocate and die. Cannabis plants, in a sense, breathe CO2 instead of oxygen. Incorporating Belimo’s dual channel self-calibrating technology, 22DTC series with ranges from 0-5000 ppm efficiently monitor levels and control the amount of outside air supplied by the air handling equipment to ensure accurate and reliable air quality providing increased production. Belimo sensors are built from the highest quality materials, delivering accurate and dependable readings over the entire life cycle of the facility. The sensors are backed with a 5-year warranty and conform to NEMA 4X / IP65 requirements.

As the legal cannabis industry and indoor farming continues to grow, there will be increased demand for custom designed HVAC systems. Belimo aims to be your trusted partner offering the added value you expect. Contact us with your HVAC challenge.

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