Two small fans or one big fan?

L

LongerzBetter

Active Member

• Oct 28, 2010

• #1

Was thinking of getting a 600w hps setup with air cooled reflector. Would a S&P TD-200(479 cfm) running through carbon filter-reflector-and out through fan or a td-150(218 cfm) cooling reflector and another one scrubbing do better to keep temperature down? Thanks in advance guys.

 

jondamon

Well-Known Member

• Oct 29, 2010

• #2

you could use the 479cfm with air cooled reflector and filter and it should work fine.

BUT


i am currently going perpetual and am redesigning my flowering closet to have a sealed lighting system.

for this i am using the following.

cooltube 600w HPS
440CFM speed controlled fan
this will be sealed so it does not pull any air from the closet

then use

180CFM fan and filter to scrub the air leaving the closet.


this way the sealed lighting system can be speeded up or slowed down depending on temps.



J

 

Medi 1

Well-Known Member

• Oct 29, 2010

• #3

more importantly what is room size for the fan size. scfrubing a room is more efficient but comes of course with more cost

 

L

LongerzBetter

Active Member

• Oct 29, 2010

• #4

Just looked up the specs and the td-200 uses 139 watts while the td-150 does 65 watts a peice. Would 293 cfm be enough to cool a 600w hps bulb? And enough to run a 6" phresh filter?

 

jondamon

Well-Known Member

• Oct 29, 2010

• #5

possibly if you could keep ducting bends to a minimum.

personally i like to overspec and control it rather than underspec and spend more. Hard lessons to learn because they cost $$$'s each time.

simple answer is overspec your ventilation and speed control it , if you speed control the 440CFM fan it usually reduces the amount of watts used to when you reduce RPM .


J

 

L

LongerzBetter

Active Member

• Oct 29, 2010

• #6

The td-150 does 291 if ran on hi speed which should be enough to scrub a 200cfm filter right? And the other one is going to cool the 600w hps alone and wil only be on for that purpose. Lights off, one td-150 will be off for the remainder of darkness and filter fan will be running in 30 minute intervals which saves electricity.

 

jondamon

Well-Known Member

• Oct 30, 2010

• #7

if you run the td150 on high speed of 291CFM then you will need a 300CFM filter otherwise air will be passing through the 200CFM filter quicker than it can clean it.



J

 

L

LongerzBetter

Active Member

• Oct 30, 2010

• #8

Wow that does make sense, but it's funny because the lady at the hydro store said that phresh filter recommended that you get a fan that draws more air than the filter is rated for. What do you guys think?

 

Medi 1

Well-Known Member

• Oct 30, 2010

• #9

ya makes sence as we loose cfm with a filter attached to it so its not relay what the rated cfm is once its all together. so less loss in cfm....

 

jondamon

Well-Known Member

• Oct 30, 2010

• #10

LongerzBetter said:

Wow that does make sense, but it's funny because the lady at the hydro store said that phresh filter recommended that you get a fan that draws more air than the filter is rated for. What do you guys think?

Click to expand...

i always match fan and filter or go a little higher on the filter.

291CFM fan pulling through a 200CFM filter will give you uncleaned air NOT GOOD.

A magazine i read in the UK is called URBAN GARDEN MAGAZINE i think its in USA too but every bit of info they suggest on grow room design and ventilation etc always gets tested before publication to make sure that its right.


this is where my calculations have been learned from. they recommend matching filters to fan sizes or a slightly bigger filter CFM .

If you have a bigger fan and smaller filter the filter cant cope with the extra CFM's the fan is pulling which is why filters have CFM ratings too.

Otherwise there would only be 4inch 5inch 6inch 8inch filters etc without CFM ratings .


J

 

L

LongerzBetter

Active Member

• Oct 31, 2010

• #11

So the td-150 ran on low setting(219 cfm) would be perfect and enough to clean the 200cfm phresh filter. Now would another td-150 running on low setting be enough to cool a 600w hps?