Cooling Grow Room With Ice- Everything You Need to Know

If your budget is tight and heat in on(in the grow room), using some ice cubes is maybe the best idea to keep the temperature in between the magical 70-75F. It’s cheap, easy to do and still gives an expected result. And today in this post, we’re breaking down everything you need to know before cooling grows room with ice.

Before proceeding any further, let’s just answer the question that you’re worried about- Yes, you can cool a grow room with ice. Make a grow room icebox with a couple of fans for sucking and blowing cool air to the tent- that’s how to cool a grow tent without ac.

But there are some conditions applied. And you can’t do that in every situation. What are they? Well, check our DIY guide on how to cool a grow tent without ac using ice only-  

Types of Growrooms that Can be Cooled with Ice

Science says that, if you freeze a gallon of water, add it to the grow room and situate the fan to blow it, the temperature should fall down. But, this process is not for every kind of grow spaces on the earth.

Usually, indoor grow tents are of small sizes starting from 2′x2′ to 4’x4’ and even 5’x5’. Unless you have a large grow room, it’s okay to go with a single ice chest. Larger ones would require an ac unit as effective ways to cool grow room.

Types of Ices Used to Cool Growroom

In a broad sense, two kinds of ices are there for the purpose- Dry Ice and Normal Ice.

  • Normal Ice
    Normal ice is the most basic type of ice that can be used in the process. With a gallon of ice, it can last for 2-3 hours. According to the size of the chest, you may need to change the size of the ice bars. 
  • Salt Ice
    Salt ice is a bit longer lasting than normal ice, as it lowers the freezing temperature. It will last a few longer than usual. Using seawater to prepare is a good idea.
  • Dry Ice
    Dry ices are made out of CO2 and it doesn’t melt by itself. With a fan placed towards it, it evaporates into CO2 and plants love to breathe that. Dry ice being bled into CO2 instead of pushing up against ice water is a more efficient idea. Plus, you don’t have to deal with any water cleanup either.

    The only issue is, this would cost you some more bucks than what normal ice would do.

Items You Need

Making an ice box is fairly simple if you’re good at DIY stuff. Here is the basic list of product that you’ll need-

  • Ice Chest
    An ice Chest of picnic cooler type will do, either of hard sided or styrofoam. If you’re looking for a cheaper alternative, a polystyrene icebox/container will also do. Here is one that I prefer.
  • Small Fan(Specs: 12V DC 10W 0.8A)
    Small and slim electric fans of 12V will be good. As they’re usually DC powered, you may need to get a 12V battery as well. And any size between 4”-6” will do. Check out this fan, or anything similar.
  • Air Duct Hose(6″ diameter x 10 feet)
    A flexible, and elastic duct hose of 4” or 6” diameter and about 10 feet length is required. Although, the length may vary on the situation. But make sure that you setup the duct as much linear as possible. This 4” duct hose is an ideal one.

Steps of Making A DIY Ice Chest for Growtent

Step 1: Cut Two Holes on The Box

At first, cut two holes on the box with a 4” and 6”/8” of diameter respectively. Usually, the larger size of the hole is to connect the ducting flange that will blow cool air to the grow room. And the smaller one is to place the fan that will drive fresh air in.
Make sure that there is enough space beneath the holes so that you can place ice and water. Also, it’s important to keep the ducting flange hole larger than the other one.

Step 2: Fasten Your Ducting and Place the Fan

With the 6 inches hole, place a ducting flange that leads to the growth without any leakage. And on the other hole, place a 12V small fan that fits perfectly and powers it up.  

Step 3: Fill the Box with Ice

Now take a bag of ice and place it inside the chest. You can break it into smaller pieces if necessary. But make sure that the sucked in the air directly works on the ice. Depending on the size of the box, and the temperature, determine the schedule of shifting the ice.

Step 4: Test, Run and Shift

Now, power up the fan and make sure the duct hose is almost linear. Put a thermometer inside the grow tent and leave it for a half an hour. If the lights and humidifier is on, you should significant fall in the temperature.

If everything aforementioned is done, you’re ready to have one of the most cost-effective grow room cooling solutions.

Some Tips Before You Start

  • Keep the duct lining as straight as possible. Any bend on the venting may reduce the fan power by 5%.
  • To avoid over-moisturization, use a digital cooling humidifier inside the grow space.
  • Keep the ice levels beneath the cutting holes. The best way would be to cut the holes on the top lid of the box.
  • The time of shifting the ice depends on the size and temperature of the box.

Frequently Asked Questions

  • Question: How much low temperature can this method bring me?
    Answer: If the size and temperature are natural, it can take the temperature down to 70-75F. See our grow room cooling calculator for more on the topic.
  • Question: How long does it last for?
    Answer: With a medium sized ice bar in, it would last for an at least a couple of hours for a 2’x4’ grow tent.
  • Question: Can I use dry ice while cooling grow room with ice?
    Answer: Yeah, dry ices are an even better option than usual ones as they provide CO2 for the plants as bi-product.
  • Question: What kind of battery does the 12V fan need?
    Answer: For typical 12V fans of 10-12mA, 8 AA batteries will do for 200+ hours.

Bottom Line

Cooling your grow tent with ice is one simple and easy idea to deal with temperature rise in a grow space. In case you don’t have an AC or want to avoid an AC unit, this is the method you should go for. But when the temperature is so high(above 80°F), that’s too hot to cool it down only with an ice box.

See our detailed guide on dealing with the high temperature inside a grow room, if mere icebox is insufficient for your heat problem.

We will be happy to hear your thoughts

      Leave a reply