Fire Safety in our Indoor Home Grow Rooms

by Alex Robles

It’s never good when a fire breaks out in an indoor grow but it’s even more tragic when that grow room is in our home.  I want to take this moment to say something about fire safety in an indoor home grow.  We’ve all heard the horror stories of bad wiring catching fire or the plant canopy getting too close to a hot light and bursting into flames.  We try not to think about it too much because aside from having a clean, safe grow area and a fire extinguisher handy, there is very little we can do when we have a fire.

I work on fire suppression systems for a living which means I spend eight hours a day talking about, learning about, installing and maintaining fire systems.  I know that a commercial grower has options.  However for our community of home growers options are limited because our realities are different.  We need simplicity because by definition we’re a hands on group that will do it ourselves if we can. Mobility is a must when some of us grow in an extra rooms, closet or cabinets that sometimes has to be moved.  There’s also the need for stealth if we’re growing our medicine in a prohibition state.

For an indoor home grow there are basically two choices from what I’ve seen that’s out there.  We either have to get an overhead fire sprinkler system or an automatic fire extinguisher (AFE).

This AFE has been in service since 1993 and is designed to cover 60 cu.ft.

Growing with fire sprinklers in the room.

Some homes come with a fire sprinkler system, which is a great thing if you have a fire.  Not so good for the grower in us and here’s why.


  • They do an excellent job at controlling and knocking down a fire that could burn your house down.


  • There’s going to be a lot of water to cleanup  when the fire sprinkler system goes off and unless you’re using waterproof equipment you may be looking at a total loss.
  • The water that rains down will have some form of bacteria in it because it’s been stagnant for so long.
  • If the plants are flowering, all that stagnant water will cause mold.
  • When the system goes off, bells and alarms will ring and first responders (fire department /police) will usually show up.

Nothing in this chain of events sounds like a good time but it could happen when you’re growing with a fire sprinkler in the room.

My AFE lets me sleep better.

The thing that I’ve found that gives me peace of mind about this is an automatic fire extinguisher (AFE).  These beautiful pieces of equipment were originally designed to put out fires in boat engine rooms.  They’ve been repurposed over the years to be used in everything from flammable liquid cabinets to server rooms and other enclosed areas where water isn’t a good idea.

The ones I use are called FireBoys  and are designed to go off automatically when the grow space/room gets to 165F-74C.  I have to get the cubic feet (L x W x H) of the grow room/space to make sure that I get the right size unit.  Each one will have enough agent in them to easily put out a fire in the size room that it’s designed for.  I also have to think about the ventilation system when I’m  talking about this type of extinguisher.  With an active or a passive air exchange, a high temp shut off should be put on the fans.  These extinguishers work by flooding the room with the agent when they go off, plus it stays active in the air for a bit to keep things from reigniting.  The intake fan could feed oxygen to the fire, which could allow the fire to stay lite or reignite easier.  The exhaust fan could suck out the agent from the room before it’s done it’s job.

Growers Note:  When you have a fire system it doesn’t mean you’re not going to have damage when you have a fire.  The system is only there to mitigate (make less severe, serious, or painful) loss if there is a fire.  You will have smoke, fire or water damage, there’s no escaping that.

Current models have a more environmentally safe suppression agent then what was used in 1993.

No system is perfect and there’s a good and bad to everything.  FireBoys are no different, but there a lot better then any other AFE on the market and here’s why.


  • Rated for class A (trash, wood, paper), class B (liquids) and class C (electrical equipment) fires.
  • The suppression agent is life sustaining which means if it goes off and you’re in your grow room, you more than likely won’t drop dead where you stand.  The air will get a little acidic but you’ll be alive.
  • The suppressing agent is considered a “clean agent” and comes out in a fine mist that won’t leave a residue on any equipment surfaces.  So there’s NO powdery film that has to be cleaned off, like with other AFE.
  • They come in different sizes to cover different size rooms, from 25 cu.ft. to over 1000 cu.ft.
  • No bells or alarms will sound when these go off unless you set it up to do that.
  • Will ship almost anywhere in the world.


  • The clean agent has NOT been tested on fruits or vegetable much less on cannabis.  If it goes off in a room with flowering plants in it, that bud is a loss in my opinion because I just don’t know if it’s safe.
  • You can’t pull a unit out of a one room and put it in a bigger room and expect it to work the same.  It won’t have enough agent to put out a fire in the bigger room.  You can however pull it out of one room and put it in a smaller room, no problem.
  • You can only get them through a distributor.  You can’t find them at the hardware store.

I hope this information encourages everyone you to think about fire safety differently, especially if you and your family live in the house you grow in.  If you want more information about different fire systems or how to size and order a  FireBoy get a hold of me.  And as always

Grow, Learn, Teach

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