grow room ventilation – Hydroponic Economics

Grow Box Guide: How to Build A Grow Box

Build Grow Box — Here is an example of a Grow Box made out of a dresser. It is very easy to do because the frame of the grow chamber is already made.

So you want to start an indoor garden but don’t know how to build a grow box. Building a grow box is actually simple once you understand the mechanics. Today you will learn every thing you need to know to build your own grow box.

The following guide will walk you through the basics of constructing a grow box out of an old piece of furniture. A lot of indoor gardeners are also very enthusiastic about recycling, so this should really hit home for a lot of you. The dresser grow box could be considered a grow cabinet, whatever you want to call it, the function is the same.

5 Reasons You Need Grow Box Plans:

1. Grow Room Ventilation: There is too much to say here. You will obviously need some sort of exhaust. The size of fan you need depends on the size of your grow box or grow room. This simple grow box uses PC fans which can be wired to an old PC power supply very easily. You can also control the timing of the fans by putting the power supply on a timer.

WARNING: Do not use the biggest power supply you can find. Stick to a smaller power supply with low wattage because the fans use very little power. If you do not know what you are doing, use a pre-made fan that you can just plug in. For 20 bucks you can get a dryer type ventilation fan that can be attached to ducting.

2. Reflective: Reflectiveness should depend on your budget. Aluminum foil is probably the cheapest material, but it certainly doesn’t reflect the most light. Since you will likely be using small grow lights, you will want to get the most out of it. White poly or Mylar are the premium choice.

3. Water proof/Bug proof/Mold proof: Water proofing is one of the most important things about building a grow box. All hydroponic systems should be in water proofed grow boxes, or outdoors where they can’t possibly make a mess. I’ll discuss bug proof more in the next point. Mold proofing takes a little common sense. Don’t use carpet for the floor of your grow box or anything dumb like that.

4. Air tight: You will want your grow box to be air tight so that light doesn’t escape, bugs will have a harder time getting in, and you will want control of the ventilation.

5. Odor control: Some people enjoy having fresh herbs, vegetables, and fruits growing in their house, but don’t want their house to smell like a garden or green house. Some people just don’t like that smell. You can get a carbon filter for the unwanted smells, but you will need to get an inline fan, which could dramatically raise the price.

Electrical Components

Please make sure all of your electrical components are away from possible water sources. You should place your outlets on the out side of the grow box and hung up. The last thing you want is water in your electrical components.

Key Components

Grow Room Fan — The small desk fan provides plenty of air movement in this small grow chamber.

Indoor Grow Lights: CFLS — Here you can see two of the small ventilation fans and a few 23w CFLs. You want to get the most surface area of each bulb facing towards the plants.

Grow Room Ventilation Made Easy

-General rule of thumb: 400CFM exhaust to 100CFM intake. Play with these numbers to see how the temperatures and air flow change. I suggest hanging digital thermometers in various locations and heights in the grow room. There are thermometers that also tell you the min/max temperatures from the day. Knowing those temperatures allows the grower to understand how their daily temps are fluctuating. Indoor grow boxes are much more efficient when they are running cool.

-Clean Green Tip: Clean grow rooms are happy grow rooms. Use carbon filters on exhaust fans and HEPA filters on intake fans. Use gas duster cans to spray away any dust on fan blades. Spider mites love to live in dust and travel through the air. Avoid spreading a spider mite infestation with a little preventative pest control.

80mm PC Exhaust Fans — PC fans are great for small grow box ventilation and circulation.

There are a few different ways to ventilate your grow room depending on the size. Small PC grow boxes, and any box roughly 2’x2’x4′ could be ventilated with PC fans or one small ducting fan. Small bathroom exhaust fans would work but may be too loud for the application. A closet grow room will need a 4″ or 6″ inline ducting fan. The inline fan can ventilate the room and clean the air with a carbon filter. If you are using metal halide or high pressure sodium light bulbs you will want the inline fan to push the air through air cooled hoods. Below is an example.

2 ducting holes for air flow. — The hot grow lights are cooled in this hood. The white ducting is the entrance for the air that is coming from the inline fan. The air is pushed through the shiny duct and to the outside of the grow box.

The grow light setup — It is essential to cool hot lights in some way. You will notice healthier plants and great results!

Key to indoor gardening: Experiment with everything to see what works in your grow room.

If you understand the principles behind the practices – you will be able to make things work with what you have. Try using a bathroom exhaust fan as the grow room exhaust. Bathroom fans are rated with CFM just like inline fans. They practically work the same. Control the flow of air with quiet insulated ducting. The noisy vibrations will certainly get annoying. Look for more posts in the future about ventilation and grow room air circulation.

Click Here to read about the 4″ Inline Fan with Carbon Filter on Amazon.com

Mother Nature has Wind, You Should Too

Fans are not just for cooling your high powered grow lights and ballasts. I use fans in every grow space to create wind. Wind will help to move the air around in your room so it does not stagnate and get used up. Plant leaves like oxygen and breathe like we do. They need a constant supply of fresh oxygen to be used at any given time. If your air never moves, your plants are losing all the extra oxygen they could be pulling from fresh air. An exhaust duct with a strong inline fan will move some air from negative pressure, but it is no where near what the plants are used to from Mother Nature.

Take a look out your window. If there are trees around you, see if their branches are blowing in the wind. Think about how brutally bent you’ve seen some trees and plants after a storm. If the plant is not uprooted or snapped, it seems to recover from the storm. You do not want to create a wind tunnel that has your plants curving to the ground, but a nice breeze is a good idea. The best thing about indoor gardening is you become Mother Nature. That means you choose the time and strength of the wind.

I use desk fans of various sizes to control air circulation in my indoor garden. I look for fans with various speeds that can be easily hung in the space I need. Letting the fans sit on the ground causes loud vibrations that get annoying after a few hours. I suggest hanging inline fans as well for the same reason. High power inline fans can get extremely loud if not hung.You can decide the location of the fans inside your grow room. I like to position at least one towards the center of the light so the hot air is pushed where the exhaust fan can pull it out. Another good place for a circulation fan is close to the intake fan. The circulation fan will move the colder fresh air where it can be used by all your plants. Check your plants needs to make sure this won’t make your medium too dry or too cold. Sometimes having a warm ballast in the room is needed for heat depending on your complete cooling system.

Wind will make your plants tough and force them to thicken their stems. Thicker stems can be beneficial for supporting a plant’s weight and ensuring the proper amount of nutrients and water to each stem. If your plants never experience wind they may be limp or droopy. If you do not introduce a plant to wind early, it may develop too thin and weak. A plant that is weak will suffer stress when it is first introduced to heavy winds. It should eventually adjust and strengthen its stem, but you may be diminishing your yield from a lack of planning. Starting seeds inside that will be transplanted outside need to be hardened off. You must gradually expose them to more light and wind until they can handle the harsh outdoors. You may have two fans of different strengths placed in two different spaces in your grow room on two different time settings. Having this much variation would vary the speed, and direction of the wind throughout the day. That type of air circulation is closer to the real experience for the plants.