newworldicon
Well-Known Member
The 6 inch will be better in the long run.
Ventilation Question +rep
- Thread starter webb107
- Start date
FootClan
Well-Known Member
just do the 6 inch its better no matter how you slice it......You get the biggest fan you can fit and then adjust the fan with a controller...... I use a 8" fan for my one light and id never go back to a 6" more air means more room to adjust your grow how you want it......Less air means less adjustments and less options........get the big fan everytime no doubt.......
ps and dont just exhaust it back into the same room your grow is in ......so tired of hearing that
newworldicon
Well-Known Member
I agree, FULL extraction from the immediate environment is crucial, I vented into the same room for some time till I put a hole and the ducting through the wall and into a different space and boy are things different What heat, humidity issues??? Go big or go home sucker!!!! LOL.
webb107
Well-Known Member
lol, thanks for the great advice man
newworldicon
Well-Known Member
no worries!
Bonzi Lighthouse
Well-Known Member
Archimedes was know to say, "Give me a place to stand and I will move the earth".
It's all about the math. Solve the equation where E = 85*(Ambient temp of grow room), A = ? (Ambient Temp at passive intake, THIS IS THE MOST IMPORTANT VALUE), D = ? (Drag on fan of Carbon Filter), C = ? (Watts HPS), B = ? (CFM of fan)
It's all about the math. Solve the equation where E = 85*(Ambient temp of grow room), A = ? (Ambient Temp at passive intake, THIS IS THE MOST IMPORTANT VALUE), D = ? (Drag on fan of Carbon Filter), C = ? (Watts HPS), B = ? (CFM of fan)
webb107
Well-Known Member
I found something from google that caught my eye take a look at this.
Air Exchange
As mentioned earlier, air exchange is a key ingredient to a successful grow room. The ideal air exchange rate will vary at different times of the year and from room to room depending on things like grow room height, etc. As rough guide about 30 air changes per hour is often recommended.
In addition to simply exchanging the air in the room to replenish the depleted co2, you need to keep it cool, this requires more air movement than replenishing the co2. I use this math equation:
A 90 CFM with a 600 watt light will raise your temperature above the intake air temp by 21°. The 240 CFM fan will raise it 8°. 90 CFM wouldn’t be enough. It’s not the size of the cabinet that you want to take into consideration; it’s the wattage being used. Watts produce heat.
(600 × 3.2) ÷ 90 = 21.33
(600 × 3.2) ÷ 240 = 8
To find how much the light will warm the room with a different size fan you can just use this formula. Just take the wattage of the light and multiply by 3.2. Then divide the CFM of the fan to find how much the room will warm in Fahrenheit degrees.
For instance:
If the temperature of the intake air is 75° and you’re using a 600 watt light, the temperature would go up 5° if you used a 384 CFM fan. So, the temperature would end up 80°.
(600 × 3.2) ÷ 384 = 5
5° + 75° = 80°
Does the formula seem right to you guys?
Air Exchange
As mentioned earlier, air exchange is a key ingredient to a successful grow room. The ideal air exchange rate will vary at different times of the year and from room to room depending on things like grow room height, etc. As rough guide about 30 air changes per hour is often recommended.
In addition to simply exchanging the air in the room to replenish the depleted co2, you need to keep it cool, this requires more air movement than replenishing the co2. I use this math equation:
A 90 CFM with a 600 watt light will raise your temperature above the intake air temp by 21°. The 240 CFM fan will raise it 8°. 90 CFM wouldn’t be enough. It’s not the size of the cabinet that you want to take into consideration; it’s the wattage being used. Watts produce heat.
(600 × 3.2) ÷ 90 = 21.33
(600 × 3.2) ÷ 240 = 8
To find how much the light will warm the room with a different size fan you can just use this formula. Just take the wattage of the light and multiply by 3.2. Then divide the CFM of the fan to find how much the room will warm in Fahrenheit degrees.
For instance:
If the temperature of the intake air is 75° and you’re using a 600 watt light, the temperature would go up 5° if you used a 384 CFM fan. So, the temperature would end up 80°.
(600 × 3.2) ÷ 384 = 5
5° + 75° = 80°
Does the formula seem right to you guys?
newworldicon
Well-Known Member
I dont even need to look at the formula....why?? Because experience has taught me that bumping up the extraction lowers temps, humidity and increases fresh oxygen and Co2 in the room, in summer you will be grateful and if the cost of a 6 ich over a 5 inch is about 20-30 bucks then go bigger. Yes 5 inch is enough but covering yourself is better in the long run, especially with HID's.
webb107
Well-Known Member
I was just asking if this makes sense or not, wasn't doubting any thing you said mate and the 6inch is like £10 more
newworldicon
Well-Known Member
No sweat, I get what you are saying, I have done the maths before, thats how we get to a 5 inch for a 600 in a 3x3 or 4x4. I see you are UK based, may I suggest this....
http://cgi.ebay.co.uk/Hydroponic-Line-Fan-c-w-Temp-Speed-Control-6-dia-/110621814391?pt=UK_HomeGarden_Garden_PlantsSeedsBulbs_JN&hash=item19c192ee77#ht_5924wt_725
Although i have seen them cheaper on the bay!
devero420
Active Member
My 2 cents...
You can always go for a 6" fan and put a dimmer on it so that you can dial in your temps. 6" ducting is available at any home improvement store.
I use one of these (the 4"). They dont have any bells and whistles and are only 160CFM, but that may be all you need. They work well for me and are relatively quiet, but I have a small op.
My friend had to use two with one on the intake, but he runs a 400w and his canopy temps are a steady 79F.
You can always go for a 6" fan and put a dimmer on it so that you can dial in your temps. 6" ducting is available at any home improvement store.
I use one of these (the 4"). They dont have any bells and whistles and are only 160CFM, but that may be all you need. They work well for me and are relatively quiet, but I have a small op.
My friend had to use two with one on the intake, but he runs a 400w and his canopy temps are a steady 79F.
webb107
Well-Known Member
Mate that is a nice find man im ordering it now thanks for the help +rep
newworldicon
Well-Known Member
WAIT!!!!!!!!!!!!!!!!!!!!!!!!!!! before you buy check out charlies hydro, I think it is £68 with them, but shop though, the link was a bit pricey!
newworldicon
Well-Known Member
You can always phone the shop, they usually are hydro stores with ebay shop profiles, just go onto there shop front on ebay and find the number, they may even have websites. I dont know why you are having the ebay issue but you only need them to find your chosen product.cuz its not letting me orderits the first time ive used ebay
webb107
Well-Known Member
Ive found a website that supplies that fan for about the same price ill just get it off there instead
newworldicon
Well-Known Member
Yeah it's a nice compact unit that makes little noise, sucks wellish and is great for settings sakes, good luck mate!