For closet-sized and larger rooms, ventilation seems relatively easy to me. However, if one is trying to ventilate a VERY SMALL CABINET, things start getting a bit more confusing.
I've read that more than 1 air change per minute stresses the plants. Therefore, putting in a big fan/scrubber on a 5 minute timer would be a terribly inefficient solution at best...
SO -- Let's suppose you have a cab with a separate, ventilated light, so heat from it isn't a factor in trying to figure out ventilation for the cab.
Now, if the cab is really small... say 20 cu. ft... and one wishes to vent every 5 minutes, then the cabinet would need only 4 CFM! Even the smaller PC fans are still around 30 CFM or so, therefore there has to be reduced air flow somewhere.
Of course, some of this will be across the scrubber... but is that the typical way cab builders do it? Rely on the scrubber to "adjust" the overall air flow created by a fan that is too fast?
Anyway, I can only think of the following ways to deal with this:
1) Scale down the scrubber (or add more carbon) so it creates more resistance to air flow (and match the speed necessary for the scrubber to work properly). However, if your fan is rated for normal operation at something like 5 times faster speed than what you need, wouldn't doing this heat the fan up, possibly causing failure, and maybe other problems such as heat? Maybe PC fans can take it, I dunno.
2) Reduce the size of the intake(s) to slow air flow. For this to work, the intake(s) would have to be smaller than the exhaust... bad idea, right? It would create extra work for the fan and be inefficient.
3) Slow the fan down using a speed control, and move to a bigger scrubber. At present, this makes the best sense to me.
I'm probably over-thinking this, or maybe it really is all over my head!
Regardless, I betcha there are still some small cab builders out there that are still confused, just like me. The math isn't the problem, it's HOW to scale down from the examples given by the pro's, but maintain fan and venting efficiency. Help!
OH, and BTW... Hellooo 420mag!
I've read that more than 1 air change per minute stresses the plants. Therefore, putting in a big fan/scrubber on a 5 minute timer would be a terribly inefficient solution at best...
SO -- Let's suppose you have a cab with a separate, ventilated light, so heat from it isn't a factor in trying to figure out ventilation for the cab.
Now, if the cab is really small... say 20 cu. ft... and one wishes to vent every 5 minutes, then the cabinet would need only 4 CFM! Even the smaller PC fans are still around 30 CFM or so, therefore there has to be reduced air flow somewhere.
Of course, some of this will be across the scrubber... but is that the typical way cab builders do it? Rely on the scrubber to "adjust" the overall air flow created by a fan that is too fast?
Anyway, I can only think of the following ways to deal with this:
1) Scale down the scrubber (or add more carbon) so it creates more resistance to air flow (and match the speed necessary for the scrubber to work properly). However, if your fan is rated for normal operation at something like 5 times faster speed than what you need, wouldn't doing this heat the fan up, possibly causing failure, and maybe other problems such as heat? Maybe PC fans can take it, I dunno.
2) Reduce the size of the intake(s) to slow air flow. For this to work, the intake(s) would have to be smaller than the exhaust... bad idea, right? It would create extra work for the fan and be inefficient.
3) Slow the fan down using a speed control, and move to a bigger scrubber. At present, this makes the best sense to me.
I'm probably over-thinking this, or maybe it really is all over my head!
Regardless, I betcha there are still some small cab builders out there that are still confused, just like me. The math isn't the problem, it's HOW to scale down from the examples given by the pro's, but maintain fan and venting efficiency. Help!
OH, and BTW... Hellooo 420mag!
