How to Build a Refrigerator Grow Box for Cannabis

How to Build a Refrigerator Grow Box for Cannabis

Don’t take an old, broken refrigerator to the dump. Turn it into a grow box instead! We’ll show you how to build a refrigerator grow box for cannabis using simple items you can find around the house. A refrigerator is the perfect grow box as no one would suspect that you are growing cannabis inside. Also, because it’s spacious and has different compartments, it is easier to place your growing equipment inside.

Why use an old refrigerator as a grow box?

An old refrigerator is the best as a grow box because of the following reasons:

An old fridge has compartments where you can place plants of different sizes

You can use these compartments to keep your plants. Most of these shelves are adjustable so you can change the height of the shelves according to your plants’ growth.

An old fridge is spacious

Most old refrigerators are spacious and perfect for keeping many plants. Also, you can use the freezer compartment, door shelves, and vegetable crisper to hold your supplies. Everything is inside this huge grow box.

You can use the compartments to hold your growing equipment

Use the different compartments to hold your lamps/lights, to keep your fans, and to hide electrical strips. Think of this as a neat and well-organized way to grow cannabis plants.

No one will suspect your growing weed in an old refrigerator

Who would suspect that you have live and thriving cannabis plants growing inside your old fridge? But to be on the safe side, keep this cannabis growing fridge in a safe place like your basement, garage, or storage area and not in full view. Keep it locked always.

Strong magnets can keep the temperature and humidity at the correct levels

Fridge doors come with very strong magnets and you can use these to keep the humidity and temperature inside the fridge at the correct levels.

An old fridge is an economical way to grow your plants

You don’t need to buy costly grow boxes, closets, and tents. You can save money and buy good quality cannabis seeds, food, and equipment instead.

How to build a refrigerator grow box

Before you start using your old fridge as a grow box, you must first remove all the fridge interior components and clean them. An old fridge will likely have food stains, bits, and spills that you must remove right away. Sometimes, pests can live inside the fridge and these may infest your cannabis plants. You need to remove these right away.

All electronic components should be removed before you install your lighting and fans for safety. Finally, the fridge door must be fitted with a good lock. You want to keep your plants safe and undiscovered.

Things you will need

  • An old refrigerator
  • Soap and water to clean
  • Lighting system, reflectors
  • At least two computer fans
  • Digital monitoring equipment


Remove all the interior components of the fridge including any electronic panels

All the components inside must be removed and cleaned. Use warm water and dishwashing soap to remove dirt, food particles, and dust. For the fridge doors, clean these with soap and water as well. Don’t close the door yet after you’re done. Let everything dry before you continue.

Clean the inside and outside portion of the fridge

Don’t forget the outside portion as well. Remove dust, rust, and chipping paint. If you have leftover paint, give your old fridge a good makeover. Also, turn the fridge around and inspect the back part. Remove all the dust, dirt, and cobwebs. You may also need to remove everything from this portion.

Use a blowtorch or metal saw to cut a hole for your intake and outtake fans

You need to install at least two fans (but you can also use three or four fans). One fan will blow cool and fresh air in while the other will blow stale used air out.

Create a hole in the size of the fans you will install. When the holes are done, secure the fan with a rubber gasket or use thick duct tape. The holes must be enough to hold the fan with no gaps to let light escape. When your holes are done, secure the fans with strong glue.

Install your growing equipment

Install the lighting with wire or strong glue. Use reflectors to reflect light to the plants. There are many kinds of materials that can reflect light like white paint, white sheets, white paper, or Mylar sheets. Use blocks of wood to lift the potted plants; you may remove a piece to adjust the height of the pots to reach the lamps.

Secure all electrical components

All electrical components must be secured at all times. Use safe electrical strips. Keep sockets and plugs away from moisture.

Install the fridge lock and decorate the outer part of the fridge

When your fridge interior is set, it’s time to secure the door with a lock. You may decorate the outer part with new paint, newly polished handles, and so on. Make the fridge more believable by placing fridge magnets, artwork, or bills.

Place your plants in

Everything is set so it’s time to place the plants in.

Important tips to maintain cannabis plants inside a refrigerator grow box

Just like any other growing tent or cabinet, it’s easy for moisture to accumulate inside a fridge and this is not good for your plants. High humidity can lead to molds and mildew also, this can affect the way your plants absorb nutrients.

As you grow inside a fridge, there will come a time when your plants start to grow larger than the fridge. To avoid this, you must grow only smaller strains so you won’t encounter this problem. The best type of strain is an autoflowering strain as these are small plants that can flower early so you’ll be able to harvest early too.

Now you know how to build a refrigerator grow box for cannabis plants, you’re ready to grow any kind of recreational strain or medicinal strain. Remember, buy your cannabis seeds only from reputable sources to get the best results.

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