[Mr Pyr0]

Originally Posted by Athos

The problem is not your current CFM, but your ambient temperatures that are too high. On the other hand 85°F (29°C) is not that high, I get those temperatures 1 month a year (January actually), the only thing that will happen is that your plants will drink more water.

If you try to get your temperatures at, lets say 76°F, your CFM needed will sky rocket to over 200, which might give you other problems like wind burn.

That ambient temperature is your usual ambient temperature or just this time of the year?

Before changing anything I would try moving your grow box to other cooler parts of the house like: the basement, a bathroom, any room that doesn't receive direct sunlight.

The other more expensive way is to cool you ambient temperatures.

Or maybe try replacing one or two bulbs with lower wattage bulbs, it might bring the temps down by a couple of degrees. Also I wouldn't worry about those temps - plenty of peeps grow weed outdoors in hotter weather than that.

[Athos]

What about your lights on period? At what time do you turn on your lights? If you are not doing it already you could make it so your lights turn on at night, for example.

In order to maintain my lights on / lights off temperatures relatively close to each other (this helps in keeping the inter-nodal space really short) my setup works like this.

Summer: night ambient temperatures 59°F to 68°F, day ambient temperatures 71°F to 82°F. Right now I'm in veg stage and my lights come on at 8:00 PM and turn off at 2:00 PM. This way my lights on temperatures are not so high and the lights off temperatures are naturally on the mid 70's. In flower they turn on at 9:00 PM and turn off at 9:00 AM.

[jonhova]

Is 10 degrees F over ambient normal? Im not tripping right now its the summer im scared for.

I think ill pull 2 lights off and see what temps im looking at then. 6x9 54 watts total.

[Athos]

How many lumens those 9 watt bulbs have? 800?

[jonhova]

About that ya

[Athos]

You might want to consider replacing the bulbs with something more efficient. For example

Currently you have 6 bulbs (9 watts each) for a total wattage of 54 watts and 4800 lumens (800 each)

You could replace them with 3 15 watts / 1600 lumen bulbs. That would give you the same 4800 lumens, but only 45 watts.

[jonhova]

Thats a good idea.

[Drop That Sound]

Another option would be to actively cool, basically adding another fan, but for the intake. You will have positive pressure unless you size accordingly. Maybe one 120mm exhaust and 2 80mm intakes, etc

I would just stack another fan to the one you got first, see if it works a little better. But by the time you keep buying 15 dollar fans you could have bough a cheap inline. You'll probably have to sacrifice some space and run it inside the cab.

If you were inclined enough you could almost get that space back by breaking down the bulbs and remote ballasting them..


Here's another one of my crazy idea's, fresh out of my oven:

Drill a 1/2 inch hole into the plastic housing of a bulb, careful not to hit the driver. glue on a 1/2 barb fitting. Drill a smaller hole on the other side for a vent.

Now, hook up a small vacuum pump, or a reversed air pump (could even use an old scrap refrigerator compressor!) with a manifold and 1/2 tubing running to all the bulbs.

Put the vacuum pump where it can't be heard. Turn it on.

Suck that heat right out of them bulbs!


I deserve an award for that idea

[Drop That Sound]

Actually, unless the vacuum pump has enough cfm to remove most the BTU's, a good fan might work better.

Think of it like air cooling HPS cool tubes on a closed loop. Then your exhaust fan can handle the ambient temps NP.


Air cooling the actual inside of the bulbs, where the hot driver is sealed up in plastic, instead of letting it dissapate into the cab is a game changer.

[jonhova]

4 lights does the trick. About 4 degrees over ambient at 78 F.

Now i gotta find something to hide the top portion carbon filter
. Something “pretty” to please the Mrs hova. Lol. She said no to a bucket.

I think a wicker basket upside down will work.