With the recent legalization of recreational cannabis in Canada, homeowners are permitted to grow up to four plants at their residence. Many will choose to grow these plants indoors to control climate conditions and light cycles, but indoor grow operations present unique challenges and some risks such as fire. Planning for and mitigating these risks will help ensure that your crop doesn’t go “up in smoke”.

A typical indoor grow setup includes several main pieces of equipment; an enclosure or tent, a light, fans, and timers or digital controllers. Here are the top risks associated with this equipment, and some easy ways to reduce the risks.

Growing cannabis indoors requires a light source. Typical setups will utilize high intensity discharge (HID) bulbs such as metal halide, high-pressure sodium (HPS), or LED lamps. The lamps are driven by a power supply called a ballast or come as an integrated unit with the bulb and power supply contained in a single component. HID bulbs can present a risk of fire as the inner arc-tube operates at very high temperatures. If the arc-tube ruptures, it can break the outer bulb glass and ignite combustible materials located below such as plastic or fabric planter pots. To reduce this risk, bulbs that are designed for “open” fixtures are available. These open fixture bulbs include an arc-tube shroud to contain the hot particles should it rupture. Some lamp fixtures also have shrouds built-in for this same purpose.

LED lamps typically operate at lower temperatures than their HID counterparts. Using an LED light can reduce the amount of heat in your grow location and reduce the risk of a fire from bulb rupture.

Many growers will use fans to circulate fresh air in and out of their grow tents, as well as to move air within the tent. Inlet and outlet fans are typically in-line fans connected to metal ducting. The fan motors are usually low-torque units that can be hazardous if an obstruction prevents the fan blades from turning. The motor will stall and pull large amounts of current from the electrical system. This can overheat cabling and the motor windings sparking a fire. To reduce the risk, use a thermally protected fan that will shut down the motor in the event of a stall or other overloading condition. Additionally, keep obstructions away from the fan blades and consider installing a screen mesh over the fan intake or exhaust to prevent branches from growing into and blocking the blades.

To power the lights, fans, timers, and controllers used in a grow setup, a connection to the building’s electrical system is necessary. This can be a power bar plugged directly into a receptacle; however, some growers will use extension cords to get power to areas that may be some distance from the available plugs. This can present a hazard if the cord is undersized and not rated to handle the amount of current draw that the equipment requires. To prevent this from starting a fire, make sure to plug equipment directly into a wall plug or high-quality power bar. Since water is one of the main inputs to growing cannabis, it is a good idea to use a power bar with ground-fault protection built in. This will deactivate the power should a ground fault occur and can prevent accidental electrocution if a cable or other piece of equipment becomes submerged in water.

While these aren’t the only risks with indoor cannabis grow operations, addressing these items can help reduce the hazards and make sure your growing season is a successful one.

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