Plant extraction—separating useful compounds from plant material—relies heavily on temperature control. While key to extracting essential oils for fragrances and pharmaceutical compounds for medicines, temperature control is particularly critical in cannabis extraction, where precise chilling determines both product quality and process efficiency.
Different extraction methods require different cooling strategies. Some need extreme cold to condense vapors back to liquid for reuse. Others depend on pre-chilling solvents to avoid extracting unwanted compounds from the plant.
Whatever the method, PermaCool™ (officially Perma Cool Systems, Inc.), a busy OEM in the extraction industry, never struggled with refrigeration. Their challenge was control systems.
The PermaCool Model 14 Elite™ system—an all-in-one chilling solution for extraction.โ
From Cannabis Pioneer to Global OEM
PermaCool officially launched in 2018, but its story goes back further. Founder David Schaefer began developing cannabis processing equipment in 2012, when the industry was still finding its footing.
“I was the fifth person to make any sort of cannabis processing equipment,” he recalls. “We began with butane extraction equipment, and as we developed our understanding of the process, it became clear that scaling to meet cannabis industry
demands presented new challenges.”
Today, PermaCool designs ethanol chillers, butane recovery units, walk-in freezers, and even custom refrigeration systems.
They operate lean, with just six core employees, relying on contractors for manufacturing and installation. Their systems are used by extraction companies around the world.
As the product line evolved, the company hit a bottleneck—outsourced control systems that couldn’t keep up.
Why Outsourced Controls Stopped Working
In PermaCool's early days, outsourcing control systems seemed logical. As a small company focused on refrigeration expertise, letting specialists handle the controls made sense.
“We originally had our control systems outsourced to a controls company,” explains Schaefer. “Making changes was hard to do. We couldn't troubleshoot or repair because they weren't our own. My old controllers were basically glorified on/off switches.”
By 2020, these limitations had led to serious business constraints:
- Reliability issues and vendor dependency: Their traditional PLC systems required frequent power cycling and had ongoing stability issues. Any software update—no matter how minor—could take weeks to implement through a third party.
- Bulky, complex hardware setups: Separate processors, I/O modules, network interfaces, and HMIs required large control cabinets that were expensive to build, hard to install, and tricky to support.
- No remote access or troubleshooting: When something failed in the field, Schaefer’s team had no way to look into it without physically going onsite— or waiting on a controls vendor that didn’t understand the process.
A PermaCool outdoor condenser unit houses compressors, fans, and refrigerant piping—all managed by the in-house controls system.
“It was our dream to connect to our customers' units and see what's going on,” Schaefer recalls. “Remote troubleshooting, system warnings, app control—these would have been incredibly valuable features, but they didn't exist with other control companies at a reasonable cost.”
When the COVID-19 pandemic forced many companies to examine operations, PermaCool saw an opportunity to make a change.
Searching for a Smarter, Leaner System
In early 2021, Schaefer and a colleague started researching control system alternatives. Key requirements included:
- Ability to handle complex process and refrigeration control
- Simplified programming and maintenance
- Built-in networking and remote access capabilities
- Cost-effective scaling and flexibility to add features without hardware overhauls
During their research, they discovered the Opto 22 groov EPIC system. The difference was immediately apparent. The groov EPIC system offered all of these capabilities in a compact, integrated package.
“Before, we would build huge 24”x24”x8” boxes full of equipment that this compact unit can do all by itself,” Schaefer explains. “Plus, the modularity allowed me to customize systems easily and cost effectively. The built-in networking capability was huge, and plugging an HDMI monitor directly into the groov EPIC made local display a breeze. Everything integrated in one unit.”
Solution: groov EPIC at the Core
Working with Opto 22 Application Engineer Selam Shimelash starting in 2021, PermaCool began standardizing their own control systems around the groov EPIC platform.
Although they make different types of refrigeration and extraction equipment—butane extraction chillers, ethanol extraction chillers, and walk-in freezers, each available in three sizes—they use the same hardware and software across the board, allowing them to scale systems up or down while maintaining consistent control logic and support processes.
Hardware Configuration
The hardware included:
- GRV-EPIC-PR1 controllers to serve as the main processor for each system.
- GRV-ODCSRC-24, GRV-ODCIS-12, and GRV-OACIS-12 digital output modules to control compressors, pumps, valves, and solenoids.
- GRV-IMA-24 analog input modules to interface with pressure, temperature, and flow sensors.
- GRV-MM1001-10 mixed I/O modules to provide flexible digital and analog capabilities.
Software Stack
The software included:
- PAC Control—Opto 22's free flowchart-based programming software—to handle both refrigeration and process control logic.
- groov View—a web-based HMI platform built into the groov EPIC—to provide operator interface and system monitoring accessible from any device with a web browser.
- OpenVPN®—virtual private network software onboard the groov EPIC—to enable secure remote access for troubleshooting and support.
PermaCool designed their systems with modularity in mind. A single
groov EPIC can control multiple extraction units, and they designed their software to allow for additional controllers as needed. Using Ethernet to communicate with motors and variable frequency drives (VFDs), instead of multiple conductor cables, cuts wiring complexity and cost.