A Zondits Interview: Growing with Desert Aire’s GrowAire™ Systems

Nick Collins, ERS for Zondits, April 20, 2018

Zondits recently interviewed Keith Coursin, President of Desert Aire, on the indoor environmental control and dehumidification systems they have designed for the cannabis cultivation and indoor farming industries. Zondits sought to learn more about the systems that Desert Aire offers, especially concerning energy advantages and any lessons for growers and/or energy utilities.


Q: You offer a system to serve the indoor cannabis cultivation market. Can you tell us about this system?

A: Our GrowAire™ Systems are integrated environmental control systems that provide cooling, heating, and dehumidification. They’re refrigeration-based, engineered solutions that provide growers with the lowest operating costs and the tightest temperature and humidity setpoint control available in the industry. We’re proud of the fact that they provide stable environments for growth and development in both lights-on and lights-off modes. All installations come with cloud-based monitoring systems with report-writing capabilities. And the systems can work with other efficient and emerging grow room technologies, like LED lighting systems and carbon dioxide enrichment systems. With our exclusive and patented equipment designs, growers are realizing approximately 40% energy savings by using Desert Aire’s GrowAire Systems.


Q: What are the advantages of this type of system? What makes it unique?

A: Our GrowAire Systems eliminate the supplemental equipment required with other grow room HVAC equipment approaches, thus lowering energy consumption. We do this by using a variable sensible heat ratio design and dew point control as our key metrics. A lot of unique engineering is built into them, including a proprietary modulating control system that maintains the discharge temperature of conditioned air. This proprietary engineering is a key factor in how we help growers maximize crop yields and desirable traits. With our GrowAire Systems, customers are maintaining constant temperatures of +/- 0.5°F from setpoint, and humidity within 1°F of dew point. And stable dew points mean happy plants.

Q: Desert Aire has identified the cannabis industry as a target market. What has drawn you to this market?

A:  Several years ago, our then-current customers of mechanical contractors and engineers would call and say they need help in selecting and sizing equipment to take care of a moisture problem. For decades we have been proud of our reputation in the indoor pool industry as being an engineering and technology leader. We had solved problems in indoor pools where water is always giving up moisture. You can see why mechanical engineers and contractors would seek us out. They figured out we could solve environmental control problems in grow rooms before we did. Now we are excited to have really refined our knowledge and equipment so that our GrowAire Systems represent the same level of custom-engineered solutions we have historically been known for.


Q: What have you seen for standard practice as far as dehumidification in indoor cannabis cultivation?

A:   We have not seen a standard practice for dehumidification in grow rooms, but we certainly strive to be the standard of excellence. Remember: growers will have their own ideas on how they want to produce their crops to get the product they want to take to market. HVAC system designers and often manufacturers have to adjust to those ideas. We need to find a common language. And there are other constraints on growers, such as limited financial resources to purchase equipment. All growers know they must control temperature and humidity and promote good airflow. But that’s not enough. We are spreading the word about the importance of using our GrowAire environmental control systems to create favorable vapor-pressure deficits that can take growers to the next level. We can help create successful, lasting grow room designs.


Q: Do you see new or expanding facilities incorporating efficient technologies or practices? What are the barriers within this industry to the adoption of more efficient practices? What do you see as possible solutions to these barriers?

A:   We are involved with multiple projects in the United States and Canada that are incorporating efficient technologies and practices involving all the inputs needed to create cultivation businesses – building envelopes, lighting systems, environmental control systems, watering systems, nutrient strategies, and energy management systems. The barriers are what you would expect of any new technology: lack of familiarity, unwillingness to be an early adopter, and that classic hindrance of chasing the lowest first costs. But the growers who are looking beyond a gold rush model to create a sustaining model know that you have to take an integrated approach with a long-term view to find the best results.


Q: It is common to hear about the energy impact of lighting loads associated with indoor cannabis cultivation. But what can you tell us about the energy associated with HVAC and dehumidification? Is that a significant part of the overall energy use?

A:   There are many factors that come into play when looking at the energy use of the HVAC system. Is the room a closed room? Is the lighting HPS or LED? And is the HVAC system correctly designed for a grow room? From what we have seen, you can expect that the HVAC and dehumidification will account for 25% to 35% of the total room electrical load.


Q: You have installed a number of these systems throughout North America, including Canada. Are there substantial differences in the design of the system based on the ambient conditions where the facility is located? Have you seen substantial differences in approaches to growing in different regions of the country? What about between the US and Canada?

A:   No, we haven’t seen substantial differences in design based on the region of the country because most of the indoor grow facilities we have been involved with are well-insulated rooms within rooms with little or no ventilation. Therefore, the impacts associated with that of outside air conditions are minimal. What we have seen is that indoor grow operations, as compared to greenhouse hybrid grow facilities, are more prevalent in the colder climates. We have seen very little design differences for indoor grow facilities between Canada and the US.


Q: As more and more regions adopt forms of legal cannabis, what are some of the big lessons you have learned that you would want to pass on to growers or utility incentive programs as it relates to energy efficiency?

A:   There are lessons, to be sure. Growers, HVAC system planners, utilities, and equipment manufacturers need to build on the awareness of the upward sloping energy demands of the cannabis cultivation industry. Certainly, it’s a good idea for growers and their HVAC system planners to include utility representatives in the early planning stages of renovations and new construction projects. We hope this inclusive planning approach, along with the approximately 40% energy savings of our GrowAire systems, paves the way for growers to receive incentive packages from utilities. This is especially true of utilities seeking to promote resource sustainability and efficiency beyond those merely offering demand-side management rate discounts.

Desert Aire can be reached online at www.Desert-Aire.com , by email at Info@Desert-Aire.com, or by calling 262-946-7400.

Desert Aire is a Milwaukee, Wisconsin, USA-based manufacturer of commercial and industrial dehumidification systems, environmental control systems, and dedicated outdoor air systems. Desert Aire systems provide healthy and comfortable indoor environments while saving energy in a variety of settings including grow rooms, commercial greenhouses, indoor pool facilities, indoor water parks, ice rinks, schools and universities, rec and fitness centers, office and retail buildings, and water treatment plants. Desert Aire is a subsidiary of Multistack, LLC. Desert Aire’s main office is located at N120 W18485 Freistadt Road, Germantown, WI, 53022, USA. Telephone (262) 946-7400; Fax: (262) 946-7401; Internet: Desert-Aire.com.

Media Contact: Tom Purdy; tpurdy@Desert-Aire.com.