The relentless and seemingly purposeful gears of natural selection have shaped the resilient and peculiar nature of the Cannabis family since its divergence from common ancestors around 27.8 million years ago among the scenery of a magnificent Qinghai Lake hidden is the myriad of vocal collars echoing on a Himalayan Plateau.(1) The landscape of the planet was gradually giving in to the cooling effects of the Azolla event and the lavish vegetation of the steppes resembled little of what now is arid and desolate landscape. The climate with moderately warm temperatures and high CO2 levels was hospitable and conducive to an astonishing variety of C3 plants.

10’s of millions of generations later, cannabis slowly descended the Himalayas before it befriended humans 12,000 years ago and found its home in all the corners of the world. The humanity’s oldest cultivated crops (2) predates Agricultural Age by at least 500 years, which inevitably ignites a yearning to ponder why it took our ancestors so long to learn to cultivate other plants. Were they mesmerized by a symbiotic relationship? Were the cannabinoids and other mind altering plants responsible for a major shift of human consciousness?(3)

The plant has been cherished by our ancestors not only for its utilitarian and medical qualities as it offered cherished moments of spiritual awakening, a brief feeling of content and hope that gave humans strengths to withstand the grinding wheels of harsh and confusing reality.

Today cannabis has become one of the most valuable crops attracting business entrepreneurs, investors and rogue agents who are pushing their way into the industry, that is not fully developed or regulated yet. After a short-lived flux of capital in the sector, the market had a sobering moment and looked at the fundamentals: the revenue and profitability. As the recreational cannabis space turned crowded in many states with dwindling profit margins, the businesses started to gear their focus on the cost of the production. Cannabis cultivation is a labor and energy intensive process and the efficiency of production became the major factor for economic viability of the businesses.

While the labor force has been minimised by augmented automation, cutting energy cost has proved to be more challenging. Indoor productions must simulate natural grow environments with high levels of PPF and a very narrow margin for temperature and humidity fluctuations through the entire maturation cycle.

Compromises had to be made to develop a healthy balance between the cost of production and the quality and quantity of the product. Innovations in LED technology have given a glimmer of hope to the operators since they produce slightly more micromoles per watt while generating less heat and reducing latent load from plants’ transpiration. However, the energy hungry HPS lights continue to dominate the market as they outperform LED’s in many categories.

Climate control for indoor facilities is the other culprit of the electrical energy cost. A grow space that operates 100 x 1000W HPS lights would need a 60 cooling ton AC system working on a recirculation mode to compensate for the sensible load from the lights and to remove 300 gallons of moisture per day. The energy cost of running an AC can be as high as of lighting, especially when auxiliary dehumidifiers are employed. Sensible load from the lights, as large as it is, is not the main factor that predicates the size of AC systems for cannabis cultivation: latent load from plant’s transpiration stretches the operational capacity of the system to its maximum. Keeping specific humidity levels below 0.006 (70F/40%RH) during advanced flowering and flushing stages is a difficult, if not impossible, task for most of the traditional cooling technologies since it requires to chill the processed air to levels well below 40F in order to effectively perform dehumidification. The processed air has to be subsequently reheated to 60-62F to avoid stressing the plants.

From an array of climate control systems that have been presently employed in the cannabis cultivation industry, chillers are arguably the most efficient and effective approach, but the cost of their acquisition, reaching in some cases as much as $100 per sf, asserts substantial financial constraints on any project. Facilities that opted for cheaper, less adequate climate solutions are faced with a constant struggle to contain temperature and humidity in indoor facilities in order to increase the quality and quantity of production while hedging the crops against fungus related diseases. The cannabis cultivation industry is well overdue for innovative climate control solutions that can ease the burden of energy cost while creating the most conducive environmental conditions. Fortunately dew-point evaporative technology coupled with rotary desiccant dehumidifiers is a viable option to solving this conundrum. Out of the few companies that operate in this market space, Air2O, an Innovative Cooling Company, is by far the most promising contender in this field. The technology, in its essence, can lower the temperature of the processed air to the wet bulb temperature of the ambient air without adding moisture and at a fraction of electrical energy consumption compared to traditional systems. In addition, it is possible to achieve any level of temperature and humidity required at every phase of a cannabis plant development.

Air2O is the next generation hybrid air conditioning system, utilizing a unique combination of indirect and direct evaporative cooling to achieve 80% energy saving over Direct Expansion (DX) compressor based systems.

Air2O’s unique ability to become hybrid and incorporate traditional DX or chilled water cooling means Air2O can be employed throughout the world and provide energy efficient cooling without compromise.

Air2O Indirect Evaporative Cooling (IDEC) Technology has a truly global reach, with applications and solutions that are best-of- breed, regardless of environment or climate. Using intelligent control systems and innovative, efficient cooling technologies saves up to 80% on energy usage when compared to traditional cooling systems. From cooling large office spaces in Europe to commercial indoor cannabis cultivation facilities and greenhouses to outdoor cooling of football stadiums and theme parks in Asia to pharmaceutical storage and process cooling in the USA, Air2O has a system to accommodate. (4)

This article was written by Air2O’s Cannabis Cultivation Cooling Engineer, Iggy Kogan.