Multiple small CFL bulbs vs one large CFL

[Wintastic]

Hi,

I'm having a little difficulty maintaining a nice temperature in my grow box.

I am using a 150w (50w actual) LED along with 6x23w CFL bulbs.

It's about on average 3 or 4 degrees Celsius warmer in the grow box than the temperature of the room. So it gets close to 30 Celsius in there when the lights are on. I doubt it's an airflow issue as I have enough CFM to cycle the air in there completely every 5 minutes or so.

I get that I should try and lower the temperature in the room but I already have the window wide open and a fan blowing air from outside in. It's warm for October where I am in Canada.

I was wondering if it would be better to have one 200w CFL vs 6 smaller ones to keep the temps more closer to the room temp? Seems intuitive that one light would be less heat than 6 small ones but I can't seem to find anything that confirms this.

Anyone know if I should just get one 200w CFL to be more efficient?

Thanks!

 

[HigherTheHigh]

Iv never used a 200w cfl but iv used a 300w cfl light for a full grow.

 

[Scientific]

You need CFLs to be really close to the plant--just inches away--for them to be as effective as possible. That argues for more bulbs.

If your humidity is low (<50 or so), you can put a big pan of water right in the air flow of the fan and that will lower the temp a few degrees by evaporative cooling. It can really help.

You say you have enough air exchange, but if the temp is rising that high, that would seem to indicate otherwise...

30 is definitely too hot.

 

[Wintastic]

Hey thanks for the recommendations!

Yes I am overestimating the airflow. All I have for intake flow is 120mm computer fan. Same for the output fan. I have a 60mm for circulation on the inside.

I will definitely place some water in front of the intake fan on the outside as per your suggestion.

Thanks for the tips!

 

[Scientific]

I will definitely place some water in front of the intake fan on the outside as per your suggestion.

The water has to be inside the tent/grow chamber to get evaporative cooling. Make sure the fan blows right on it. Anything to you can do to increase the surface area (e.g. sponges in the pan sticking up) helps. Look up "swamp cooler" (evaporative cooler) for more info.

 

[Wintastic]

Thanks for the heads up. I have out some Dixie cups in with some water. Luckily today is higher humidity because of some rain. I rearranged some lights too, because you mentioned they should be really close. They are only a few inches away from the plant now.

Temps have been steady today at around 24.5 Celsius with the lights on. I think the higher humidity and rearranging of the CFLs have helped with the temperature.

Thank you so much for the insight!

 

[Scientific]

Thanks for the heads up. I have out some Dixie cups in with some water. Luckily today is higher humidity because of some rain. I rearranged some lights too, because you mentioned they should be really close. They are only a few inches away from the plant now.

Temps have been steady today at around 24.5 Celsius with the lights on. I think the higher humidity and rearranging of the CFLs have helped with the temperature.

Thank you so much for the insight!

Looking good!

In my experience, you want at least a 13" x 9" baking dish full of water to have enough surface area to get significant cooling. It's not about the humidity, it's that you only get significant evaporation and thus evaporative cooling if the humidity is low.

Moving the lights in close will help a lot. Some aluminum foil reflectors can help a lot too.

 

[Wintastic]

Looking good!

In my experience, you want at least a 13" x 9" baking dish full of water to have enough surface area to get significant cooling. It's not about the humidity, it's that you only get significant evaporation and thus evaporative cooling if the humidity is low.

Moving the lights in close will help a lot. Some aluminum foil reflectors can help a lot too.

Thank you so much for the help. My plant is doing very well compared to my last grow. I'm progressing very well so my next grow I will probably scale it up a bit more.

 

[Scientific]

Thank you so much for the help. My plant is doing very well compared to my last grow. I'm progressing very well so my next grow I will probably scale it up a bit more.

That seems to be the way it goes, or at least that's how it went for me--learn by doing. I'm glad everything is going well.