Carbon Filter/Fan Ratings Inaccurate?.

Sunbiz1

Sunbiz1

Well-Known Member
You would think companies that market these products for "horticultural uses" would know enough about the product to give first time consumers the proper information.

A 440 CFM rating is not adequate for a room measuring 400 cubic feet. Had I known this, I would have spent the extra $80 for the 800 rating along with larger filter.

Now I have to buy a second one.:-|
 
SnapsProvolone said:
You sealed / CO2? How are you exchanging air if not sealed?
Click to expand...

There are about 1,000 small air leaks in this *basement utility room*, it's why I used it among it being the coolest room in the house during summer.

I need a second rig, or a larger one to be effective in my specific applications...yes?
 
Sunbiz1 said:
You would think companies that market these products for "horticultural uses" would know enough about the product to give first time consumers the proper information.

A 440 CFM rating is not adequate for a room measuring 400 cubic feet. Had I known this, I would have spent the extra $80 for the 800 rating along with larger filter.

Now I have to buy a second one.:-|
Click to expand...


You have to allow for performance loss due to restrictions placed on the ventilation system by various things such as
Carbon filter - up to a 25% efficiency loss.
Ducting runs - I think its something like every 10feet of ducting reduces around 5% efficiency.
Bends in duct work - every 90 bend is a 20% loss.
Lighting. 600-1000w - add 15% to your room cf for open reflectors. 5% if air cooled using the fan.

So for example. To do the job with a 1000w open reflector in a 400 cf room.
400/100 = 4 =1% of the cf. 4*15= 60. So our fan currently needs to be 460.

4*25 = 100. This allows the carbonF to be attached. =560

With one 10Ft duct run. 4*5=20.
20+560=580.

So in order to ventilate your room and cool the area with the chosen 1k light you need 580CFM of fan power with matching or higher CFM filter.


That's how I would have personally worked out the area for ventilation.


J
 
jondamon said:
You have to allow for performance loss due to restrictions placed on the ventilation system by various things such as
Carbon filter - up to a 25% efficiency loss.
Ducting runs - I think its something like every 10feet of ducting reduces around 5% efficiency.
Bends in duct work - every 90 bend is a 20% loss.
Lighting. 600-1000w - add 15% to your room cf for open reflectors. 5% if air cooled using the fan.

So for example. To do the job with a 1000w open reflector in a 400 cf room.
400/100 = 4 =1% of the cf. 4*15= 60. So our fan currently needs to be 460.

4*25 = 100. This allows the carbonF to be attached. =560

With one 10Ft duct run. 4*5=20.
20+560=580.

So in order to ventilate your room and cool the area with the chosen 1k light you need 580CFM of fan power with matching or higher CFM filter.


That's how I would have personally worked out the area for ventilation.


J
Click to expand...

Yes,finally,someone else gets/understands it!
 
jondamon said:
You have to allow for performance loss due to restrictions placed on the ventilation system by various things such as
Carbon filter - up to a 25% efficiency loss.
Ducting runs - I think its something like every 10feet of ducting reduces around 5% efficiency.
Bends in duct work - every 90 bend is a 20% loss.
Lighting. 600-1000w - add 15% to your room cf for open reflectors. 5% if air cooled using the fan.

So for example. To do the job with a 1000w open reflector in a 400 cf room.
400/100 = 4 =1% of the cf. 4*15= 60. So our fan currently needs to be 460.

4*25 = 100. This allows the carbonF to be attached. =560

With one 10Ft duct run. 4*5=20.
20+560=580.

So in order to ventilate your room and cool the area with the chosen 1k light you need 580CFM of fan power with matching or higher CFM filter.


That's how I would have personally worked out the area for ventilation.


J
Click to expand...

Seems about right, should have bought the 8 or 10 inch set-up b/c highest rated 6 I can find is 530...TY for the additional info.

Cheers
 
Ou8aCracker2 said:
Yes,finally,someone else gets/understands it!
Click to expand...

I've been using the calculations I mentioned for about 4years. Been growing just over 4 years.

URBAN GARDEN MAGAZINE had a great article called "planning your grow" which talked about designing rooms within rooms for better heat control, restrictive forces placed on fans by other equipment and bends etc.


I've tried to broadcast the info any time someone needed help designing rooms.

Unfortunately though UGM has ceased publishing.




J
 
And most folks just say, "well my reflector is a 6", so I need a 6"fan right?"

Then the hydro store owner says " exactly! You need a 6inch"

Without even asking them room dimensions.

That's what happened to me the first time until I educated myself about the grow rooms calculations.

I had a 180CF room and got sold a 5" cooltube and a 5"/120CFM fan to cool and ventilate a 600w. Fine during winter growing but couldn't even cope with summer AT ALL.


Now I use a thermo controlled 6"@250CFM with an open reflector with a 400w HPS in the same 180CF room.

Golden temperatures!!!



J
 
How do u like that scrubber combo
i was thinking og piking up a 440ventech for about $20 less.
Is this one better in anyway?
 
Well most hydro shops assume you'll be doing it the proper way which is using one fan on a carbon filter solely for ventilation and another fan used closed loop just to cool the light(s)....so you can't blame them and when using one fan fir aircooling the light and ventilating,it more than just growroom size and light used,you also have to throw ambient/fresh air intake temp into the equation too.
 
Ou8aCracker2 said:
Well most hydro shops assume you'll be doing it the proper way which is using one fan on a carbon filter solely for ventilation and another fan used closed loop just to cool the light(s)....so you can't blame them and when using one fan fir aircooling the light and ventilating,it more than just growroom size and light used,you also have to throw ambient/fresh air intake temp into the equation too.
Click to expand...

Some hydro shops, yes, others will let you explain what you want to do and still sell you inadequate equipment.

I must admit though that the closed loop way of running a lighting rig gave me the opportunity to reuse that inadequate 5" as a filtered exhaust while I upgraded fans to run the air cooled rig.

J
 
Ou8aCracker2 said:
Well most hydro shops assume you'll be doing it the proper way which is using one fan on a carbon filter solely for ventilation and another fan used closed loop just to cool the light(s)....so you can't blame them and when using one fan fir aircooling the light and ventilating,it more than just growroom size and light used,you also have to throw ambient/fresh air intake temp into the equation too.
Click to expand...

Yes, I am using it unconventionally. The additional fan in the room is the source of the problem, shut that off and smell goes away. It is causing air to escape before it can be filtered.

So for my purposes, I should have over-sized the inline fan/filter. The other fan I only use when I run mercury vapor bulbs(UV)along w/an HPS, only b/c plants do need some air circulation as I do *not have any heat issues.
 
You must log in or register to reply here.

Similar threads

xox
help me find a carbon filter of equal or greater quality
Replies
9
Views
628
coreywebster
coreywebster
D
Measuring cfm for optimal ventilation
Replies
10
Views
926
McStrats
McStrats
G
My fan and carbon filter are 4 times bigger than the required space
Replies
1
Views
180
vostok
vostok
G
Aurora Cannabis stock slammed as analysts rush to cut price targets and re-up sell rating
Replies
0
Views
240
gb123
G
G
Legal Cannabis in Canada has Meant High-Cost Low-Quality Cannabis Products
Replies
10
Views
737
OldMedUser
OldMedUser
Back
Top