Summer is definitely here in San Diego! Even though we have some of the best weather in the world there is still a certain time of the year when we have to battle the heat in our grow rooms. There are a few different ways to manage temperatures in a grow room;
- Run your lights during the coolest part of the day – at night!
- Use air conditioners.
- Cool your lights directly using air or water cooled systems.
- Have a proper ventilation system.
There is more than one right way to cool your grow room because every grow room is going to have its differences; the size and shape of the room, the configuration of the room, how many lights used, outside temperatures, and how well that room is insulated in order to hold consistent temperatures. Proper temperatures can be kept by using these methods alone or together in different variations.
A good place to start is with the ventilation system. This is probably going to be the least expensive starting point plus it is a good idea to have a proper ventilation system set up for any indoor garden even when running a closed system with CO2. The ventilation system is used to remove warmer air and replace it with cooler fresh air. Keep it simple, use an exhaust fan that removes air at the top of the room (because heat rises) and use an intake fan that blows in the fresh air at the lower part of the garden. Now this method is only going to help cool your room if the intake fan is pulling in air that has a lower temperature than your garden. So find a way to pull your intake from the coolest side of the house. If possible bring this air from under the house, basement or garage, as long as the air you are bringing in your garden is relatively cooler than your garden or outside temperatures.
Air conditioners or water cooled systems are still needed in some situations. Especially when living inland where temperatures are a lot higher and cool fresh air cannot be brought into the grow room. Using an air conditioner is a more traditional way to cool your grow room. There are a few different types of air conditioners. There are window units that sit in a window or a hole in the wall where air is taken in through the front of the unit, cooled, then pushed back out into the room. The problem with these units is that they are not completely air tight and some air is taken out of the grow room without proper filtration (so pollen, strong odors, etc.. may escape the room). Portable ACs are good if they have an intake and exhaust hose for cooling the motor of the unit. The major downfall of portable units is that they take up floor space that can otherwise be used for plants. The mini split style is very efficient, does not remove any air from inside the grow room and the only floor space taken up is from the outdoor part of the unit. One drawback of the mini split unit is that it is more expensive than the other styles.
Water cooled systems are an efficient way to control heat because water holds temperature more efficiently than air. Therefore, less cooling power is needed to maintain a certain temperature with an equal volume of air and water. Yet we still need to cool the air in the room. You can use one water chiller to cool a reservoir which can cool your lights (cooling the lights will limit the amount of heat created from your grow room) and use the same water to cool the air in the room. Fresca Sol makes a light fixture that you pump water through which can reduce the heat from your bulb up to 93%. The cold water can also be pumped through a product called the Ice Box (the water gets pumped through a radiator style metal grate and as the air passes over the cold metal the air is cooled). Multiple Ice boxes and Fresca Sol fixtures can be used with one reservoir as long as the chiller is able to keep your water cold.
One of the main benefits with an indoor garden is the opportunity create the perfect environment. With the proper planning and equipment anyone can beat the heat no matter how hot it is outside.