With so many dehumidification and HVAC offerings on the cannabis grower market, it can be difficult for growers to choose the system that is right for their specific situation.
For Geoff Brown, VP of Technical Solutions for Quest, learning as much as possible about what is happening in a customer’s grow space and how the cultivator is likely to operate that space is critical to assist growers with equipment selection.
For example, Quest’s IQ dehumidifiers each represent a different offering for the market, largely based on the requirements of a particular cultivator or system.
“To pinpoint this, we really need to partner with the growers,” says Brown. “[We must] Find out everything they are going to do with this system, how they are going to do it [and] how you expect your system to operate. “
To help determine which equipment is best, Brown recommends growers consider the following factors:
1. Size of the operation
The size of a grow operation is a key factor in choosing a dehumidification and HVAC system, according to Brown. The Quest Evolution, for example, is a split indoor unit with a ventilation device inside the system and a dry cooler attached outside as thermal protection.
“It’s like having an air conditioner in your house where you have your stove or air handling unit inside and then you have a condensing unit outside,” says Brown.
The dry cooler uses a food-grade water-glycol mixture that is available in all Quest IQ systems that provide cooling. In this way no refrigerant lines are required. So if there is ever a leak in the system, the food grade glycol or water will leak onto the roof of the facility or into the growing room rather than the refrigerant which could damage the infrastructure or plants.
These types of systems can operate in all environmental conditions, Brown adds, and can manage a growing space from 300 to 2,500 square feet.
According to Brown, lighting should play an important role in determining the HVAC and dehumidification needs in a grow space.
“The main driver of system demand is lighting – what type of lighting, what illuminance, and how many [lights there are],” he says.
The lights represent the energy going into the system and the lights generate heat that needs to be dissipated by the air conditioning system. He adds that some of the light is also converted by the plants to power transpiration processes, which creates the need for some dehumidification.
A grower’s plan to water their plants is another important piece of the dehumidification puzzle, Brown says. Hydroponic and open tray systems create different dehumidification needs, for example by creating different levels of evaporation in the room.
4. New build vs. retrofitting
Brown says new systems often perform better with an all-in-one dehumidification and HVAC solution, while split systems are often better suited for retrofitted systems.
“In general, new builds tend to be better off with the all-in-one solution, if only for the sake of simplicity,” he says. “They only do checks [one] or maybe two units in one room instead of possibly dozens, so the control side is much easier. “
In addition, the installation costs for the all-in-one solutions are often lower, as electricity and plumbing are only required for one or two units instead of several.
“Then you waited a unit or two on the maintenance side, not dozen,” says Brown. “The maintenance items in a grow room – even just replacing filters – can be a pretty tedious task, and there are quite a few of them. It is therefore important to reduce the maintenance effort. “
For example, the IQ series compressor wall units are primarily placed on rooftops as more traditional air handling units.
“They’re more suited to larger new builds, especially in the US,” says Brown, adding that the units are ideal for rooms with more than 1,000 square feet of canopy per room and facilities with more than 10,000 square feet of total canopy area. “We see some regional differences here. Canada by and large prefers split units for indoor use because it’s cold and it’s cold [is difficult] Servicing units that are on the roof in the middle of winter, while the US generally doesn’t get that much of this cold time of year. “
Split systems – an independent dehumidification unit plus cooling – are often used in retrofit applications where an existing building already has cooling.
“Many retrofitted units, especially in the southern US, do not have a roof [space] available or enough structural loading available to bring equipment to the roof, ”Brown adds. “So, maybe for structural reasons, go to a breakup.”
5. Plant layout
Brown said producers will want to evaluate their plant layout and space considerations, especially in a retrofitted plant where plans for a dehumidification and HVAC system were not built into the blueprint from the start.
“Especially in the world of retrofitting, [placing Quest’s] Indoor IQ products take up a lot of space, ”says Brown. “If you have a new building in which you have the opportunity to build this infrastructure from day one, it makes a lot of sense. If you’ve already shared an existing building and sacrificed an area for equipment, it probably doesn’t make sense. “
Cost is certainly an important consideration for growers as they venture out to select dehumidification and HVAC equipment, says Brown.
While the up-front cost of a split system is typically lower, it may not be as efficient or inexpensive to run in the long run, he adds.
“If you have a facility or a new licensed vendor that is just getting started, the cost of capital may be more important than the cost of ownership,” says Brown. “It can be something that you upgrade afterwards.”
7. Speed to market
Some states have time constraints between getting a cultivator’s final license and harvesting a first crop, or growers may just want to get to market faster on their own, Brown says. In these cases, it may make more sense to use a standard solution than a purpose-built product like Quest’s IQ series.
“Although we have a few models in stock, most are made to order, which can take 8 to 12 weeks,” he says.
8. HVAC control systems
Cultivators should also think about how the dehumidification and HVAC systems will be controlled or integrated with the rest of the building’s fertilization and lighting controls, Brown says.
“From my point of view, it is probably the thing that we spend the most time on in order to understand the control system from everyone involved,” he says. “The dimensioning of devices is relatively easy, but it can be a little more difficult to use this space as a system.”
The grow room should be designed as a system, Brown adds, rather than a collection of parts. Adding or changing devices afterwards can be extremely difficult. Therefore, planning ahead is key.
“This is more of a mindset than a checklist and real advice to the grower,” he says. “You don’t want a bunch of different systems to be put together on an ad hoc basis, you want a space designed that takes all aspects into account from the start – lighting, HVAC, humidification, CO2 control, ventilation, cleanliness, access control and building design. Each of these things can cause or prevent growth and must be considered together during the design phase. “