Greg's 75g

[hillegom]

Were u an engineer in your past life?
Kudos

[gregzz4]

Originally Posted by hillegom

Were u an engineer in your past life?
Kudos

Thanks Dietmar !!!
I wish as I would have retired by now with the money I could have made !!!

I have another update to come as my first plan didn't work out as it should have

Stay tuned ....

[Madreefer]

Hey that's a great idea. Good job!!

[gregzz4]

Originally Posted by Madreefer

Hey that's a great idea. Good job!!

Thanks Bill

[gregzz4]

Looks like the chiller fan outputs more than I figured on and one fan wasn't quite enough, so now it's really ugly

Second fan running @ 133CFM









Needed to mount the Wye to the wall


And whole ugly setup

[hillegom]

This version two looks good to me. Works better I'm sure.
Ideas just sprout from you

[gregzz4]

I'm going to change it once more as I can feel a little air leakage from the opening at the bottom of the tote - probably due to back pressure
I'm going to run 2 independant ducts from the storage tote and connect them to 2 independant vents with the fans pulling instead of pushing
This way I'll get 100% airflow from each fan and zero heat in the room

[WarDog]

Originally Posted by gregzz4

I'm going to run 2 independent ducts from the storage tote and connect them to 2 independent vents with the fans pulling.

Yeah buddy, thats the way to do it correctly. That wye you got set up is improper venting practice to the extreme. Too much back pressure causing an air flow bottleneck. Great diy project!

[gregzz4]

Ya I was hoping that wouldn't be the case but these fans just can't create enough pressure

[daplatapus]

Originally Posted by WarDog

Yeah buddy, thats the way to do it correctly. That wye you got set up is improper venting practice to the extreme. Too much back pressure causing an air flow bottleneck. Great diy project!

Looks great! I was expecting a lot worse from your description.
In the strictest of air flow practices, if those are 4" lines you'd need a 4"X 4"X 6" Y for it to work as you'd intended. Just use Pi R squared to figure out the square inch of 4" round (X2 for 2 pipes running into one) verses the size you want to run it into.
I highly doubt those fans are pushing the limit of a 4" pipe though. A 10' run (including friction loss for elbows) at .05 inches static pressure loss, a 4" pipe can flow 45.8 CFM. That's pretty low static pressure, but I'm not sure what pressure those fans can push without cavitating.

A thought to also consider... I have had some instances in a somewhat similar application of 2 fans feeding from a common plenum. One fan started a few seconds before the first and from the suction it created in the plenum it pulled air backwards through the second fan and the blades of the second started rotating backwards. Sometimes the motor's are not powerful enough to counteract that reverse spinning and they just sit there cavitating until they either burn up or shut down from overheating. What fixed it for me was just installing a baffle between them, making 2 separate plenums.