HVAC professionals consider a multitude of variables when designing HVAC systems for grow rooms. But, one issue that often gets overlooked is odor control. Growers are often restricted in how they handle the crops’ distinctive odors. A proper HVAC system can help control odor issues without compromising the humidity and temperature controls that are vital to crop survival.
Understanding the Odor Issue
Terpenes, the plant’s oil-producing compounds, cause the distinctive marijuana smell. Each strain has a unique aroma, so it’s no surprise that many experienced growers can easily identify the strain type just from its smell.
Odor from a single plant is bearable. When there’s an entire grow room of plants, the odor can be overwhelming. Traditionally, growers used ventilation to help control air flow and humidity in the grow room. This allows the odors to escape outside. However, many places have restrictions on how much untreated air can be released. This is especially true in urban settings.
There’s a critical need for an HVAC system to play a bigger part in odor control.
Using Air Filters and Scrubbers as a Temporary Solution
Smaller growers often install air filters and scrubbers in the HVAC system. This allows “cleaned” air to be vented outside. Typically, carbon filters are used to collect the strongest odors as the air moves through the system on its way outdoors. The larger the operation, the more frequently filters have to be changed.
However, using filters and scrubbers can add significant costs to an operation. They are also not effective for larger scale commercial growers.
Commercial Growers and Sealed Greenhouses
Instead of using air filters or scrubbers, commercial growers use sealed greenhouses instead. These sealed buildings trap all of the odors inside and prevent anything escaping outside. They do not have any outside exhaust from the grow room.
But, this creates another issue. Ventilation helps control humidity, temperature, and air flow. Without proper ventilation, growers must rely entirely on the HVAC system.
Why Traditional HVAC Units Don’t Work
Traditional HVAC units rely on coolant to control room temperature, and work best in closed systems. For marijuana growers, these units pose several major drawbacks including, increased energy consumption. Marijuana grow operations are already energy intensive, so any extra energy used impacts the bottom line.
Traditional units also dry the air. Marijuana plants need humid conditions, especially in the early stages. If a traditional HVAC unit is used for cooling alone, other arrangements have to be made for air flow and humidity control.
Indirect-Direct Evaporative Cooling (IDEC), a solution for grow rooms
The newest types of evaporative cooling systems are a better fit for commercial growers. These new systems use the latest technology to give growers greater control over temperature, humidity, and air flow, while using significantly less energy.
IDEC systems use 80% less energy than traditional HVAC units. Because they use evaporative cooling instead of coolant to reduce temperatures, they do not dry out the air. They also help:
- Manage odors
- Bring in fresh air from outside, as needed, to help with air flow and humidity control
- Adjust humidity levels during the different plant’s growth stages
- Control sealed greenhouses with a simpler setup
- Avoid secondary systems and additional equipment
- Reduce energy consumption