Creating an Indoor Grow Room

Female hands hold young tomato seedlings in a box in a brightly lit grow room.
What You'll Need
Black mylar sheeting
Table or stand for plants
Lights and cabling
Timer for lights
Intake and exhaust fans

You can make an indoor grow room as elaborate or as simple as you desire. Plan ahead to make sure that you have the required light to stimulate optimum growth. Take care not to let the plants dry out, and ensure that air is being vented to provide the plants with the necessary fresh air and stabilize the temperature in the room. Follow those rules, and you will do fine.

Step 1 - Choose a Suitable Space

Decide on the size and location of your grow room. You can convert a garage, attic or even a closet to create a grow room. A grow room requires an electrical source (any normal wall outlet will do) and a nearby water supply. Carpets hold more moisture and bacteria so if you have a room with a wood, cement or tile floor that would work best. Lights and pumps create noise, so plan ahead if you are a light sleeper or have neighbors. A room with windows will allow for natural light during the day which will cut down electric usage. The room will require an exhaust fan and vent to provide proper air exchange.

Step 2 - Draw a Floor Plan

Map out your ideas for your grow room on paper. Add dimensions and placement of key elements like, exhaust fans and intake vents. Determine the size of your room, figuring out both the square and cubic feet of the room. This will allow you to purchase the correct size of lights, fans and vents. Decide where in the room your plants will go. This may be determined by where you will have to place lights and exhaust fans due to the outlets and structure of your room.

Step 3 - Insulate the Walls

Line the walls and floor of the room with mylar to prevent moisture damage. Tack the mylar directly on the walls as flat as possible.

TIP: Our expert gardening advisor, Karen Thurber adds, "Mylar will also reflect the light around the room, making maximum use of your light source."

Step 4 - Install Lights

The lights must match the size of your grow room for maximum effectiveness. Generally, you need one 600-watt light for every 5 to 6 feet of room.

Remember also that lights make heat, so the more lights, the bigger the extractor fan you need. If you use natural light during the daylight hours, your lighting system needs to be connected to a relay and timer system.

Step 5 - Install Exhaust and Intake Fans

Drawing in fresh air and expelling hot air is especially important. Air needs to flow in at the bottom of the room and be extracted at the top, where the hottest air would flow naturally. The input fan should be smaller than the output fan. Air needs to flow in from inside the house, where the temperature is stable, to outside the house. Create this exchange of air 30 times per hour.

Additionally, positioning a fan's airflow toward the light bulbs will help keep temperature down.

TIP: Karen advises, "The use of HAF fans (Horizontal Airflow) will help maintain an even temperature and humidity level throughout the grow room. It will reduce condensation on the walls and help reduce the incidence of disease on your plants."

Step 6 - Water

Lights will cause the plants to dry out quickly, so make sure to water frequently as needed. Often people with indoor grow rooms install a hydroponics system to automate this part of their indoor grow room setup.

TIP: Karen says, "Different crops have varying light, humidity, and soil requirements. Research the plants you will be growing to know what is optimum for your grow room."