Hello GC, Was wondering how much heat is emitted from a 400 watt bulb on a digital ballast. Using a 2x4x5 grow tent with mylar interior. The ballast has a 10' cord from ballast to socket, so the ballast will be housed outside of the grow tent to keep any heat it may emit out. Couldn't afford a cool tube, might DIY soon, but how hot will the 400 watt bulb get? I plan on using a 6" duct booster fan and ducting to blow out the hot air, and passive intake is built in to the box. Will this keep temps low and fresh air in the tent? Any helpful suggestions would be appreciated.
HID bulbs get hot. I have a 1000watt set up. the space I am utilizing for my grow is 12x5x8. Half of that space is for growing and the other half is for all the equipment(humidifiers, dehumidifier, fan, and other equipment. I run a separate intake and exhaust system just for the light. I have cooler air running across the light 24hrs a day. i do this because my plants are currently in a 24hr on veg cycle. I also have an intake an exhaust system just for the room. If the temps get to hot, the exhaust fan will come on to vent hot air out. It usually comes on every hr or so because I have the thermostat set at 76. Here is what I would do if i were you. Get a carbon filter. mount it high in your grow space. attach a dryer vent hose from the filter to your light. then run another dryer vent hose from the other side of your light to a squirrel fan that will exhaust air out of the tent. By doing this you are eliminating smell and heat from your grow space. If this is done correctly with the right amount of air flow, you will be able to touch the glass on your hood without burning yourself. Also make sure the are intake for your grow room is as low as possible. It probably wouldn't hurt to mount a little fan at your intake so it is constantly pulling fresh air into the room.
Thanks for the suggestion! So in the meantime before the cooltube is setup, what kind of ventilation should I have? Will I need to set something serious up? I want to have a 6" duct booster fan pulling air out at the top, with ducting leading to the vicinity of my bulb to suck hot air out of the tent. Will a 160cfm duct booster pull out enough air to keep fresh air coming in on the passive intake? Will I have high temps with that setup in 2x4x5?
Length x width x height will give you the total size of your grow area. You want to be able to have complete air exchange every 5 minutes. CFM stands for cubic feet per minute. calculate the total area of your grow room and get a fan that will have a high enough cfm to move that amount of air. You have a small setup so you shouldn't have a problem exchanging air. Im not exactly sure what you mean when you say cool bulb. That usually means light spectrum. Cool bulbs tend to be more blue then red. Are you using MH or HPS?
HPS, and I was just saying that I don't have the cooltube reflector yet, will get there eventually. So with a 160cfm duct booster sucking air out of the 80cf tent the temps should stay low enough just about not to mess with my yield?
aight secured a fantech fx8 481cfm 8" fan, could I just make a DIY carbon scrubber and call it a day for ventilation/temp control on the box? Will i need anything else to pull the hot stale air from the 2x4x5 cab with a 400watt hps and batwing? Will the fan be able to create enough negative pressure to keep cool air coming in from the passive intake grills on the side of the box? I will have an oscillating fan in the cab as well to move the fresh air around if it is being sucked in.
Try it out and see. I can tell you this. I have a 6 inch duct fan set up directly to my glassed in light sucking the heat off of it. I also have a cfm set up in the box to suck out the smell and extra box temperature. With both cfms my box stays 10 degrees above the room temperature. So as long as I keep the room 65-75 my box is in good shape.