How Grow Houses Work

Cooling the Marijuana Crop

­­All these lights can pose numerous problems. For starters, the electrical wiring in most living rooms is only capable of powering a single 1,000-watt bulb. To power more lights and additional electrical devices, you're going to have to perform quite a bit of rewiring or hire an electrician who doesn't mind getting his or her hands dirty. Plus, to cut down on the massive amounts of electricity numerous lights require, growers often stagger their "days" among different rooms in the grow house so that a minimum amount of power is required at any given time.

­There's another side effect to stuffing a house full of horticulture lamps: incredible heat. Without proper ventilation and air conditioning, many grow houses would experience nighttime temperatures of more than 100 degrees F (38 degrees C). This isn't just a matter of cutting down on how many grow house workers succumb to heat stroke. Marijuana grows best at temperatures between 70 and 80 degrees F (21 and 27 degrees C), but can thrive at 95 degrees Fahrenheit (35 degrees C) in a well-lit, CO2-heavy environment. Growers also keep planters and pots elevated on tables to keep root systems away from the cooling influence of floors.


Growers use air conditioning and ventilation fans to maintain a constant temperature for their marijuana crop. Every 1,000-watt bulb requires one fan and 2,800 British thermal units (BTUs) of cooling [source: Cannabis Culture]. To put that in perspective, a typical 5-ton air conditioner puts out around 60,000 BTUs. As stated above, sustaining very high levels of CO2 permits higher temperatures. This is because the hotter it is, the more CO2 marijuana plants consume, which also results in thicker buds. But the constant use of powerful air conditioners also increases a grow house's demand for electricity, as well as water in the case of water-cooled units.

­Finally, marijuana plants are subject to harm from a host of parasitic insects, spores, fungi and mildews. Some growers use ionizers and ozonators to control pests and remove harmful agents for the air. Others champion the use of charcoal filtration systems or just regularly increasing CO2 levels high enough to kill harmful pests. Plus, growers who seal off everything in a closed growing environment decrease the risk of outside contamination.

­Appeasing the plants is one thing, but operating under the radar of law enforcement is another. On the next page, we'll look at what measures growers take, as well as how cops try to snatch their crops.