150 watt HPS - Are my temps too high?

[BillyBud420]

Hey!

I will be growing a sing plant under a 150 watt built in ballast HPS. I am checking out temperature at various distance from the light and have some concerns. I am using a 2 x 2 x 5.4 small tent.

Here are the numbers:

12 inches away - 33.5 C / 92 F
16 inches away - 31.5 C / 89 F
24 inches away - 30.0 C / 86 F

My ventilation is a 6" duct fan, venting out the top. (160 cfm)

Are these numbers a problem?

Any thoughts? I could put a small fan in the tent, pointed at the light / plants to try to cool them....I could add another duct fan on the input port of the tent...

Thanks for any help!

 

[JuanCarlos]

Those temps are a bit higher than you would optimally want. At 24 inches you may be able to get away with it. What's the temperature of the room that the tent is in?

 

[BillyBud420]

Those temps are a bit higher than you would optimally want. At 24 inches you may be able to get away with it. What's the temperature of the room that the tent is in?

Thanks for the reply! The room sits around 68 F (20 C).

Would increasing cool intake help? I get that the temp outside would help, but i was wondering if the lights radiant heat would overcome any cooler air being pushed in...

But then again, others use these lights so maybe bringing in more from outside the tent could work...

 

[BrixNewb]

I have a 4'x4'x6.6' tent and with my room at 68 degrees I am able to maintain 80 degrees or below in my tent under 750 watts of HID lighting. I believe your problem is that you need more cool air intake. I believe your fan should be able to pull enough air out of the tent no problem. I do not suggest getting a fan to bring air in. You should be able to use passive intakes and do the job just fine. Also it may be a good idea to put your thermometer above the light so you can get an idea if your fan is doing it's job or not. I would expect temps above your light to be about 2 degrees cooler than under the light.

 

[JuanCarlos]

I am guessing that your light isn't air cooled Billy? That would be the big difference between you and BrixNewb. In your space you may only have enough room for a cool tube, but I think that it would be worth the investment if you can get one.

 

[LEDBud]

I suggest a fan blowing over the top of the plants and into the reflector.

The plants will be fine with the 150w at 12 inches distance , light diminishes fast over distances and your going to need all the 150w can offer.

If need be move the light around the tent through out the day to give all of the plant/plants some prime time light hours.

A Cool-Tube would be best , I am using one vertically next grow to supplement some LED panels.


With a cool tube at 6 inches it would boost your 150 watts output to that of a 400w at 18"

 

[BillyBud420]

I suggest a fan blowing over the top of the plants and into the reflector.

The plants will be fine with the 150w at 12 inches distance , light diminishes fast over distances and your going to need all the 150w can offer.

If need be move the light around the tent through out the day to give all of the plant/plants some prime time light hours.

A Cool-Tube would be best , I am using one vertically next grow to supplement some LED panels.


With a cool tube at 6 inches it would boost your 150 watts output to that of a 400w at 18"

Thanks!

So, something like this would work?

It kinda sucks because I bought a Sunsystem 150 integrated unit and now only need the bulb from it if I go for the cool tube. Such is life!

 

[BrixNewb]

Yes, that is a cool tube. I can't be much help on if it's any good or not, but that is the general idea. I find that growing in a tent needs an air cooled light. If you drop your room temps down below 68 degrees it will be a bit cold in the room for most people. Getting my tent dialed in was one of the things that took me the most time. It really helped to have a weather station that has multiple sensors so I could place them at various points in my tent and track down the different temperatures.

 

[LEDBud]

I like the model that has a small reflector inside the tube , it comes with a clip on exterior reflector. Its more efficient as most of the light is passed threw the tube once without being reflected back threw it again.


You could keep your 150w and buy a 400w ballast and cool-tube. the 150 would be great for the seedling stage / small plant stage.


its nice having lighting options for the stages.

Thanks!

So, something like this would work?

It kinda sucks because I bought a Sunsystem 150 integrated unit and now only need the bulb from it if I go for the cool tube. Such is life!

 

[BillyBud420]

I like the model that has a small reflector inside the tube , it comes with a clip on exterior reflector. Its more efficient as most of the light is passed threw the tube once without being reflected back threw it again.


You could keep your 150w and buy a 400w ballast and cool-tube. the 150 would be great for the seedling stage / small plant stage.




its nice having lighting options for the stages.

So, is this a better design?

 

[LEDBud]

Yep , thats it , with aluminum ends and inner reflector.
6 inch wide x 24.5 or 25 inches long.

that price is good with free ship

 

[BillyBud420]

Yep , thats it , with aluminum ends and inner reflector.
6 inch wide x 24.5 or 25 inches long.

that price is good with free ship

having a hard time figuring out what Cool Tube will fit in a 2 foot wide tent.... I think they are all too big...once you attach ducts to either end.

I was looking at this...

Can anyone point me to a cool tube combo set that would fit in my small 2 foot wide tent?

Thanks all!

 

[LEDBud]

With a 150w a cool tube is not so important either.
thats right 2x2 is not suited for the tube.

Try the fan pointed up at your reflector , it will drop the bulb temp and even out the reflector heat.

 

[BillyBud420]

With a 150w a cool tube is not so important either.
thats right 2x2 is not suited for the tube.

Try the fan pointed up at your reflector , it will drop the bulb temp and even out the reflector heat.

Thanks LED. I will try the fan route!

 

[Fuzzy Duck]

More likely a ventilation issue to which you may need to exhaust the warm air else where to tame the temperature.

 

[LEDBud]

A 2nd 160 cu.ft 6 inch duct fan would work great as a Intake fan , it would take some load off the exhaust fan allowing it to vent more effectively.

You can use a Dimmer switch for a speed controller and wire both fans to one dimmer (with a proper rating)

Two fans run at the same speed hardly raise the db level over using a single fan. Especially when using identical fans.


~~~~~~~~~~~

If you have the cash buy a fan speed controller , if not the hardware stores have a wall mount fan speed controller much like a dimmer.
Some dimmers are good for motors , fan motors , look into it if funds are tight.


When using a intake fan it gives you control over where the cool air goes , instead of letting the exhaust draw it from the bottom vents and up the side of the tent.