negative air pressure

pokey

pokey

Well-Known Member
Are their any cons to making your exhaust extra beefy so that there is negative air pressure inside your cab? I'm thinking in an apartment grow where smell is critical it would be nice to be able to work with the door open without any smells escaping.

Now before you say anything about less airflow or something, realize that the intake can be large too, it's just that the exhaust needs to push out more than the intake can let through, so you've still got plenty of air circulation.
 
ivintheterrible

ivintheterrible

Well-Known Member
cons noise and power. thats bout it if you got the money. i use a tent and air cool a sealed reflector so temps dont bother me the all i have is a 170cfm fan pulling air through a carbon scrubber. keep passive air intakes open works great so dont go overboard
 
FullMetalJacket

FullMetalJacket

Well-Known Member
No man I prefer big ass exhaust fan for that reason. For stealth/ neg presssure when entering the cab. I use a speed controller to speed it down when door is not open.

I use a 478 cfm fan on a 36 sq ft cab. I can only max it at 200 cfm though as that is what my filter is rated for. I notice if i really crank it up when cab doors are open though it actually does better because it treats all the air (good neg pressure) just doesnt treat all that air as well. But works for me.

Because stealh is a security of mine i picked up an xt-400 oxone generator as well. I use it mainly for shock treatment of odors. If you turn it on high for 5 min there is no smells whats so ever. It also has a timer/remote on it so you can turn it on for 1 a min or two right before you leave the room. I think they are great to have on hand in case of emergency fan failures, land lord visits etc. Just read about them to learn more if interested. You dont want to hurt you or the plants...

Stay stealthy man...

Iviinthe terrible is right about noise and power though, but if you turn down the spped when the cab doors are shut the larger fan is actually quiter than a smaller fan running full speed. For me the extra power usage is worth it.

--Actually does anyone know if you have a fan that is say 100 watt and you turn it down using a speed controller, do you use less watts of electricity ? TY
 
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ivintheterrible

ivintheterrible

Well-Known Member
FullMetalJacket said:
No man I prefer big ass exhaust fan for that reason. For stealth/ neg presssure when entering the cab. I use a speed controller to speed it down when door is not open.

I use a 478 cfm fan on a 36 sq ft cab. I can only max it at 200 cfm though as that is what my filter is rated for. I notice if i really crank it up when cab doors are open though it actually does better because it treats all the air (good neg pressure) just doesnt treat all that air as well. But works for me.

Because stealh is a security of mine i picked up an xt-400 oxone generator as well. I use it mainly for shock treatment of odors. If you turn it on high for 5 min there is no smells whats so ever. It also has a timer/remote on it so you can turn it on for 1 a min or two right before you leave the room. I think they are great to have on hand in case of emergency fan failures, land lord visits etc. Just read about them to learn more if interested. You dont want to hurt you or the plants...

Stay stealthy man...

Iviinthe terrible is right about noise and power though, but if you turn down the spped when the cab doors are shut the larger fan is actually quiter than a smaller fan running full speed. For me the extra power usage is worth it.

--Actually does anyone know if you have a fan that is say 100 watt and you turn it down using a speed controller, do you use less watts of electricity ? TY
Click to expand...
yes your using less watts because your not at full power. i have a 4 inch incline fan at 170 cfm and it is so loud it sounds like a jet is powering up in my closet. any recommendations for a fan withe equal or higher cfms thats not insanely loud
 
ivintheterrible

ivintheterrible

Well-Known Member
btw 100 watt fan running at half speed equals 50 watts easy to figure out once you understand my electrician buddy enlightened me
 
FullMetalJacket

FullMetalJacket

Well-Known Member
ivintheterrible said:
btw 100 watt fan running at half speed equals 50 watts easy to figure out once you understand my electrician buddy enlightened me
Click to expand...
Thanks.. maybe that was a dumb question, electricity is def my waek points. I wasnt sure if you still drew the same amount and it was just output as heat on the motor or converted somewhere else...lol..i dont know. TY

I like the S&P fans. The fans really quite especially if you go big and dial them down. They are compact too. You still have wind noise but you will have that with any fan and can be adjusted based on the speed obviously... But someone that can do compliacted wattage usage equations probably alreay knew that...lol

Soler & Palau Commercial Centrifugal, Axial, Propeller, Exhaust and Supply Fans - Soler and Palau - HVACQuick.com
 
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