Clarifying the Complexity of Cannabis Controls

Surna Control cannabis controlsIn the cannabis industry, the term “controls” is thrown around a lot. It means something different to every supplier based on their level of sophistication and experience.

In general, controls will remove the human element from cultivation operations, minimizing the impact of mistakes or oversights and ensuring what is supposed to happen, happens, when, and how it’s supposed to happen. However, correctly applied controls systems can have enormous additional benefit, far beyond simply enabling lights or irrigation pumps at the right time. In order to understand what your controls system can do for you, you must first understand what it is you’re getting from your chosen supplier.

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Most growers think of controls as the dashboard where they can see their room parameters and adjust photoperiods or temperature setpoints, and they make their decisions around controls based solely on that user interface. This is an important part of the toolkit, but it is the least critical piece to a controls system’s functionality.

The real complexity, and expertise, lies in the programming between the dashboard and the critical processes. For instance, when the temperature setpoint on a user interface/dashboard is changed, any number of important actions must take place, from simply providing power to a compressor in the most basic systems to reading a leaving air temperature and modulating a valve in more sophisticated systems.

Sometimes, cultivators might think they’re getting a controls system, when in reality, they’re just getting a good-looking dashboard. Then they’re unpleasantly surprised when they realize that the dashboard isn’t really controlling anything.

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When evaluating controls systems, it’s important that the companies you’re considering have been vetted by your lighting, HVAC, and irrigation system providers to ensure they’re really giving you all the functionality the critical systems in your facility require. Here’s some help on what to ask a controls and automation vendor.

In industry-speak, when someone says controls, it can mean a number of things: actual controls (enabling and disabling critical functions in the facility), automation (performance of critical functions in the facility), and data collection (collecting data relevant to critical functions in the facility). These systems generally fall into three categories of sophistication.

The first is entry level, or simple enable/disable controls paired with some data collection and limited alarming. This is the category that the vast majority of controls companies in the cannabis industry fall into. These companies enable and disable lights, CO2, cooling and dehumidification, and irrigation based on timing, thermostat set point, and/or EC or moisture reading in the cultivation media. Or, more simply: when this happens, turn it on, and when this happens, turn it off.

The sophistication associated with true building management systems is lacking in this type of approach, but the dashboards are usually tailored to the needs of the cultivator, and this type of approach is certainly better than no controls at all.

More sophisticated controls systems will step up the data collection to include run time and energy use associated with equipment, and additional zones where data is gathered. More importantly, they allow for modulation of the equipment being controlled in the facility. Most commonly this modulation means adjusting lighting levels based on spectrum or PPFD, and modulating HVAC equipment to respond with precision to changing loads.

In addition to improving precision, modulating controls for HVAC in particular can have significant energy benefits — essentially, the same effect that highway miles on cruise control vs. stop and go traffic have on gas mileage in a car. In order to take full advantage of modulation in controls systems, the HVAC system design must have modulating capability, whether that’s modulating hot gas reheat in DX systems, where refrigerant volumes, compressor speeds and sometimes fan speeds are modulated, or four pipe chilled water, where water temperature and volume, compressor speeds, fan speeds, and pump speeds can be modulated.

This modulation component has been very difficult for most controls providers to achieve but is necessary for maximum performance at minimum energy use. More sophisticated systems can also provide the option of alarms associated with equipment failure, so the cultivator knows there is an issue to be addressed before that issue impacts the cultivation space.

Further benefit can be realized by ratcheting up the sophistication and adding analytics into the mix — taking the data that has been collected and reviewing it against cultivation functions to improve performance.

This can be as simple as adjusting the controls sequence of operation to minimize energy use in an HVAC system, or as complex as identifying trends between two seemingly unrelated events to tweak SOP’s. There are some companies that provide grow room analytics, which are usually integrated with controls. Many cultivators, with the proper level of data collection, can perform these tasks manually as well.

Any of these levels of sophistication can have enormous value to the cultivator. Simply enabling and disabling critical processes reliably will remove the element of human error and limit risk, along with reducing manpower requirements and improving efficiency. However, the more sophisticated the system, the greater the potential benefits.

Read more from Surna here.

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