Ventilation Explained - Part 2

Posted by BTN Admin on | Tags: Tutorials , Ventilation

Ventilation Explained

Part 2 - Venting your lighting systems

Now that we are in the grips of a hot summer, one of the most frequently asked questions from our customers is on cooling HID (High Intensity Discharge) lighting systems. There are a many methods that can be used to adequately cool your lighting system. We will be looking at a few types of setups that can be used in small to large grow rooms.

Air Cooled Reflectors

 Air-cooled lighting involves the use of inline fans and ducting to extract heat away from the lamp

and out of the growing area. All air-cooled reflectors sold by BTN can be sealed with a tempered glass lens, isolating the heat of the lamp from the cooler environment of the grow room. The main purpose of utilizing an air cooling system for HID lights is to efficiently extract the heat produced by the bulb before it has a chance to pass into the growing area.

Air-cooling offers several benefits to the indoor gardener:

Reduces or eliminates (especially in summertime) heat problems - lamps are the primary source of unwanted heat. A properly air cooled light can remove up to 50% of the heat of the lamp.

Gives greater control over temperature and humidity in the plants’ growing environment, allowing for optimum growth rate management and the development of healthier plants and higher yields.

Allows HID lights to be placed closer to the plants, increasing the intensity of the light they receive, thus resulting in faster growth rates and larger yields.

Reduces the cost of running a large air-conditioner in the growing room.

Most growers use vent fans to replace hot air in the grow room with cooler air from the outside, but this practice can quickly deplete CO2 tanks when supplemental CO2 is being used. By air cooling the lights, you can reduce the temperature of the grow room enough so that you don't need an exhaust fan, or at the very least, get away with a small air conditioner.

Helps keep the bulb cooler, resulting in less bulb stress and failures.

It is much easier to remove heat at the source rather than try to get it after it has entered the grow room. Due to the small volume of air in the reflector (compared with the entire volume of the grow room), much less energy and effort is required to remove the same amount of heat.

Cool Tubes
The combination of Reflux Internal Reflector Bulbs (such as Gavita, Relighting, GrowLab, Chrome Dome, etc.) and Cool Tubes gives the grower a powerful lighting system that is efficiently cooled. Cool Tubes allow the grower to extract heat from the bulb completely without having to deal with the resistance of a large cumbersome reflector. Heat transfer from the bulbs into the grow room is minimized as all of the air being sucked from the fan passes directly over the bulb, efficiently removing the heat. This, coupled with the all of the benefits of the Gavita bulb (internal reflector that is optimized for the arc tube, no dust collecting on the reflector, enhanced spectrum, etc.) makes this combination perfect for indoor grow rooms.

There are many methods to cooling HID lights. Here are a few:

Type 1 - Inline Series (without CO2)

There are many variations of this type of setup. In this setup, the system used to air cool

the lights is also used to ventilate and clean the air being exhausted from the grow room. This system effectively uses one fan to do the job of two fans. The fan will need to be sized larger than what is required to just ventilate the room. The fan will need to pull air through a carbon filter, through one or more lights and exhaust the hot air. This system is suited for small to medium growing areas without the use of CO2. The fan should be running continuously during the light period (which means it is possible to plug the fan into the same timer that is used to operate the lights [provided they both don't exceed the amperage rating of the timer]). Ideally, the fan should stay on a little longer, since it takes a while for the bulb, reflector, ducting, etc. to cool down completely (which means you would have to use a second timer).

Type 2 - Inline Series (with CO2)

This type of cooling system pulls air (preferably from a cool air source) through the lights and exhausts it outside or into another area. The air passing through the light never comes in contact with CO2-rich air in the grow room. This allows the grower to control CO2, temperature, humidity and also groom ventilation. This also allows the grower to create a sealed environment. This type of setup is suited to small to medium sized areas. If 2 x 400w lights are being used in a grow room, then a 4" or 6" fan could be used to cool the lights. If the air that is being used to cool the lights is warm/hot, then a 6" fan should be used; if the air is cool then a 4" fan can be used. Use 6" ducting to connect the fan to the reflectors. With the addition of a 6" Motorized Damper on the intake side, you will get the added benefit of keeping moisture and dust from entering the system

at night, which could cause condensation and alter the temperature and humidity levels in the grow room as well. The Zone Control Damper should be plugged into the same timer as the fan. When the lights turn on and the fan is activated to cool the lights, the Zone Control Damper is also activated, thus allowing cooler intake air to cool the lighting system. Alternatively, you could install a 6" inline booster fan on the intake side in place of the damper. When the lights turn on and the fan is activated to cool the lights the booster fan is also activated, creating positive pressure in the air cooling system and increasing the air flow and efficiency of the system. This is especially useful if you decide to add another light in the future or you find that the single fan system isn't moving enough air (which is a common problem when you use too much ducting or too many sharp bends in the duct run).

Materials required:

Air Cooled Reflectors

Ducting to match reflector and fan - 4", 6", 8"

Duct Clamps - 4", 6", 8"

Centrifugal Fan

Motorized Damper

Timer For Fan

Grow Yoyos

Type 3 - Parallel Series (Without CO2)

This type of system is similar to Type 1 above, however this configuration is more suitable for larger growing areas. This system utilizes only one fan to cool numerous lights. It is more efficient to cool lights this way instead of using one fan to pull air through numerous reflectors in one line. It's not efficient to pull hot air from one reflector into another (which is also producing heat) into another (even more heat) and into another (yet more heat). This will cause too much heat to radiate from the hot reflectors into the grow room. It also puts a tremendous strain on the fan when you go from a 10" or 12" fan into a long run of 4" or 6" ducting. This strain will shorten the life of the fan and use more energy. By using "Y" Adapters you can can go from a 10" or 12" fan into two 6" or 8" runs - a much more efficient solution to the problem. You can either leave the intake ends on the last two reflectors open, or (as illustrated below) you can add another "Y" Adapter, ducting and a carbon filter to clean the air before it comes in contact with the system. Not only does this prevent any odor from exiting the room, it also keeps dust from entering the lighting system, which could accumulate on the glass lens and reduce the amount of light available to the plants.

Materials required:

Air Cooled Reflectors

Ducting to match reflector and fan - 4", 6", 8"

Y adapters - various sizes

Duct Clamps - 4", 6", 8"

Centrifugal Fan

Carbon Filter

Timer For Fan

Grow Yoyos

Type 4 - Parallel Series (With CO2)

This is by far the most popular setup for air cooled lights that are utilizing supplemental CO2 in the growing area. As with the Type 2 system above, air is pulled from another area to cool the lights. With the inclusion of a "Y" adapter the grower can air cool numerous lights with only one fan. If 4 x 1000w lights are being used in a grow room then an 8" or larger fan should be used to cool the lights. Use an 8" x 6" x 6" "Y" Adapter to run from the fan to the reflectors. BGH offers several different sizes of "Y" Adapters and Duct Reducers allowing you to use just about any size fan with any size ducting. The same setup can be used on the intake side with the addition of an 8" Motorized Damper or 8" Inline Booster Fan (as explained in Type 2, above). The Zone Control or Suncourt fan should be plugged in with the same timer as the fan. When the lights turn on and the fan is activated to cool the lights, the Zone Control or booster fan is also activated, thus allowing cooler intake air to cool the lighting system.

Materials required:

Air Cooled Reflectors

Ducting to match reflector and fan - 4", 6", 8"

Y Adapters - various sizes

Duct Clamps - 4", 6", 8"

Fan

Carbon Filter

ZoneMaster Motorized Damper

Timer For Fan

Grow Yoyos

 

BTN realizes that properly planning and installing an air cooled lighting system can be a daunting task, especially for beginners or when many lights are involved. Feel free to contact us with any questions you may have prior to placing your order and we'll be happy to assist you in choosing the right equipment for your unique situation.