AHU and humidifier space constraints?
AHU and humidifier space constraints?
(OP)
Im building up an Air handling Unit on site with a humidifier and due to space constraints etc... I have the following question. The AHU fan handles approx 15m3/s (31000cfm)
Q. The humidifier is going to be located down stream of the fan outlet. The fan is a DWDI centrifugal and the humidifier will be placed in a plenum the same size as the AHU cross sectional area and about 2 metres long (6 ft)....straight off the fan outlet. After the humidifier section there will be a bank of HEPA filters. The question is, will the velocity and turbulance in the plunum due to relatively high dischage velocity of the fan be too high for the steam humidifier...will there be carry over of condensate onto the HEPA filters???
Q. The humidifier is going to be located down stream of the fan outlet. The fan is a DWDI centrifugal and the humidifier will be placed in a plenum the same size as the AHU cross sectional area and about 2 metres long (6 ft)....straight off the fan outlet. After the humidifier section there will be a bank of HEPA filters. The question is, will the velocity and turbulance in the plunum due to relatively high dischage velocity of the fan be too high for the steam humidifier...will there be carry over of condensate onto the HEPA filters???





RE: AHU and humidifier space constraints?
If you absolutely need the humidifier there, I think the Dri-Steem Ultrasorb has something like a 9-inch maximum vapor trail. You could also limit humidification by lowering the high limit humidistat (in the supply duct, downstream) to less than 80% or so - if you can still achieve your objective at that value...
RE: AHU and humidifier space constraints?
Please disregard my first post I misunderstood. The fact of the matter is that a proper humidifier should handle velocities anywhere from 300 to 3000 FPM. 10 duct dia is still a good idea for proper mixing
RE: AHU and humidifier space constraints?
Velocity in a duct purely depends upon the duct size. For a recirculatory system we always go with equal sized supply and return main ducts. In this case, if the velocity is a concern, you may have problems both at supply and return of the fan. The main reason for water carryover is not the velocity but the pressure (I mean static pressure at discharge) that balances the weight of the liquid particle and keeps it in the air stream. (This is the same principle used in pneumatic conveying)
Regards,
Eng-Tips.com : Solving your problems before you get them.
RE: AHU and humidifier space constraints?
I hope imok2
Regards,
Eng-Tips.com : Solving your problems before you get them.