Help me choose wisely

Skyhound

Skyhound

Well-Known Member
Hello all,

Im planting in a grow room with 60x60x160cm .

I have two hps kits one with 150w and the other with 250 w .

The problem is that im getting temps of 85 fahrenheit / 29 celsius with the 250 w hps .

Ventilation is ok one main extractor 180 cfm with 3 passive air flow windows , one intractor with 100 cfm and oscilating fan on
the canopy . On the hand it doesnt feels like its 85f/29c its fresh on canopy .

So my dilema is put back the old hps kit with 150w and a slight decrease on temps , or go with this temps and maximize my light power .

Thank you for ure time
 
Attikus112

Attikus112

Well-Known Member
Where are you taking your temperature measurements from? Where are you extracting the air from? Do you have a carbon filter attached to the 180cfm? You grow area is around 21 cubic feet so should be capable of refreshing the air around 9x a min with that fan and no restrictions. Have you considered a hood or cool tube for your light? Is your ballast local or remote? What's the temperature differences between ambient and your grow area (temp rise)?
 
Skyhound

Skyhound

Well-Known Member
Hi Attikus112 ,

im taking temperatures at cannopy level with shield from radiation light 29c and pot level 26/27c, im extracting in a room with open window with carbon filter attached .

I considered cool tube but i dont have space to atttach it to carbon filter and extractor so not possible . ballast is remote and temps outside are -9-10c
 
Attikus112

Attikus112

Well-Known Member
You have about 4 square feet that you're working with so the 150w is probably considered under powered for your space. It seems like your options are:
  • Figure out how to get a vented hood or cool tube installed, maybe something inline with the filter
  • Or get a stronger fan
  • And/or look for a larger carbon filter to improve your air flow rate
Are you using any ductwork on your fan and filter? I've used a separate ventilation system for a light in the past but it can lead to issues with odor control.
 
Skyhound

Skyhound

Well-Known Member
Solved the problem , hope it helps some people in summer that cant afford having ac on 12 hours .

First i tried putting a small fan directly pointed into the light , it had 0 effect in the thermometer so i toke it off .

Then i tryed putting a big oscillating fan directly in 1 of the passive intake hole outside the tent i knew this would work with ac but didnt expect this next thing to happen , and damn i went from 31ºc 87.8 °F to exactly 25.0ºc 77 °F , wich i think are nearly perfect temp for floration right ?

thanks for help
 
Attikus112

Attikus112

Well-Known Member
Glad you figured it out. Just be careful with inlet fans, if your inlet cfm exceeds your exhaust cfm you'll end up with positive pressure in your grow area and that will lead to odor control issues.

77F is perfectly fine for growing though, good luck.
 
Attikus112

Attikus112

Well-Known Member
You mentioned having multiple passive inlets. You could see if smoke or something similar is drawn into one of the passive intakes.
 
Skyhound

Skyhound

Well-Known Member
ahah yah thats how i usually do it but i have it in a corner in a closet so i have only acess to the intake hole that is being vented , im gonna try to peak on one side , thanks for the help
 
Skyhound

Skyhound

Well-Known Member
ive done some tests and i think i created positive at least on half the side that the big fan is pushing , can i use this in this beggining of flower and stop once the smell starts coming ?
 
JoeBlow5823

JoeBlow5823

Well-Known Member
Skyhound said:
ive done some tests and i think i created positive at least on half the side that the big fan is pushing , can i use this in this beggining of flower and stop once the smell starts coming ?
Click to expand...
Its a tent. It is either positive or negative. Are the sides sucked in or pushed out?
 
Skyhound

Skyhound

Well-Known Member
thats whats strange if u see it in vertical i have half side on a straight position and half side being pushed out so i guess i have positive , can i use it in beggining while i plan other way to get temps down , about the cool tube with filter do any of u see it happening in a 60x60 cm space
 
JoeBlow5823

JoeBlow5823

Well-Known Member
Skyhound said:
thats whats strange if u see it in vertical i have half side on a straight position and half side being pushed out so i guess i have positive , can i use it in beggining while i plan other way to get temps down , about the cool tube with filter do any of u see it happening in a 60x60 cm space
Click to expand...
I think we need pictures of your setup to figure out exactly what is going on here....
 
Skyhound

Skyhound

Well-Known Member
i reached the other hole and sometimes it pulls sometimes it pushes , it should only be pushing , so this is not a long term solution , but can i have positive pressure without affecting plant biology ? at least till the smell comes ?
 
JoeBlow5823

JoeBlow5823

Well-Known Member
Skyhound said:
i reached the other hole and sometimes it pulls sometimes it pushes , it should only be pushing , so this is not a long term solution , but can i have positive pressure without affecting plant biology ? at least till the smell comes ?
Click to expand...
Plants dont care about the air pressure differences made by fans lol.
 
Skyhound

Skyhound

Well-Known Member
lol i dont know they say they breath better under certain conditions, so i can use this as short term in beggining of floration , i dont have other option does a system with cooltube reduces much the temps? i have new main extractor to install it has 197 cfm but because im in 60x60 with cool tube extractor and filter i have to do lots of curves with ducting will i not loose very extraction power?
 
Attikus112

Attikus112

Well-Known Member
Anything you add to the airflow path will add to the total air resistance so by adding the tube you will reduce your air flow rate. A cool tube or hood is suppose to remove the heat from the source before it mixes with the rest of the air in your tent so hopefully it will result in a reduction in temp despite the reduction in cfm. I had a diy version of something similar to the example below. I haven't needed one since switching to LEDs so that is also an option if you decide you can't make the hps work in your setup.
1588730257320.png
 
Skyhound

Skyhound

Well-Known Member
hi attikus thanksfor all ure help .

That might be the solution , leds , im very new to this type of light, how many watts of leds would i need for my tent 60x60x160cm
 
Attikus112

Attikus112

Well-Known Member
I generally try to aim for around 50W per square foot. The W/sf recommendations don't really change based on the type of light so you would want a 200W to 250W led light. If you look for one make sure it's actually 200W and not 200W equivalent. Quantium boards style lamps would probably be your best option given the space constraints but their expensive. They have a large number of smaller leds under driven to increase efficiency and reduce heat. The large number of diodes would also help with light uniformity compared to a COB. I've grown with DIY blurples, COBs, and now I'm working with Cree Performance XHP50 LED Modules which are similar to my COB setup but i have 4x as many and run them softer. There are lots of posts on the forum about LED lamps though.
 
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