TC Controls was contracted to install HVAC controls for a large cultivation facility. During the preconstruction meeting, the construction team discovered that wiring installation for fertigation, Co2 and lighting controls had not been covered by any trade. We suggested that we should perform the installation because it was low voltage, and we would be able to incorporate the installation during the HVAC controls installation – reducing the impact of the unanticipated additional cost.
Our design team quickly realized that the individual process control systems (fertigation, HVAC, lighting and Co2) were all designed to be stand-alone. We knew this would be a severe problem once the cultivation facility was up and running, as there would be no communication between the four control systems. To solve this issue, we worked directly with the grow control vendor and established a two-way communication protocol. This communication allowed the grow controls to talk to the building management controls to provide the environment needed for that particular grow cycle. Through our building management system, we were then able to quickly adapt to the changing environmental requirements.
Another design issue that developed after the system was commissioned, was related to the heating & cooling plant. The plant was designed around a modular heat recovery chiller to generate hot water and pre-cool the chilled water as a byproduct, before entering the air-cooled chillers. The system was designed around the demands of the entire cultivation facility being at full grow capacity. When the building was turned over, the chiller plant kept tripping off, and we were unable to see what was going on because the units were designed to exclude BACnet communication with the BMS. Our team realized that the facility was not generating enough load. The engineering team did not take into account the transition from no capacity (seeds germinating) to full capacity (flower rooms full). To overcome this issue, our team had to create a false load and continually make adjustments as more rooms were brought online, allowing the chiller plant to function properly.
The vague HVAC sequences of operation provided in the design documents have also required continuous fine tuning in order to meet the simultaneous temperature and dehumidification requirements.
Overcoming these design issues has allowed our customer to ramp up capacity in their facility as scheduled. Through 24 hour monitoring our team has been able to detect and fix problems before they became issues for the facilities Grow Master, protecting the facilities valuable live crops.