Howdy..
I picked up a squirrel cage fan/blower assembly from a furnace dealer to use in the air exchange system for my studio. My question is:
Do I use this fan as an exhause and have a passive intake or the opposite, use the blower to pump air into the studio and have a simple vent to exhaust the air?
I have studied the box type mufflers and will include integrate them into the design.
Thanks...Doug
FAN question
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knightfly
- Senior Member
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- Joined: Sun Mar 16, 2003 11:11 am
- Location: West Coast, USA
Assuming the fan is larger than needed, I would first slow it down; if it's direct drive, this would require a solid state speed control, which can (will) generate AC line noise; you can plug the speed control into a good surge suppressor (don't plug anything ELSE into this) and connect to the NON-studio gear phase of your power; that way, the surge/noise suppressor will attenuate any RFI generated by the speed control, plus what's left will be on the "dirty" phase AWAY from your studio gear's supply.
With air handling, slower = quieter, hence that recommendation.
I would put a filter ahead of the input to the blower, then put the blower on the INLET side of the studio; this will require longer and better absorbed ducting, because there is a slight noise penalty (not sure how much) due to the noise source being "upwind" of the studio - however, the plus side is that this will give you a slight positive pressure in the studio, so that every time you open the door you will "sweep" some of the dust OUT of the studio instead of sucking it in.
Rod prefers to have fans DOWN stream because of the extra noise possibility; I've always had problems keeping things dusted, so my idea is to increase duct length/size/number of turns to compensate for the slight diff in noise, and keep the benefit of a slightly pressurized room.
Don't, however, make the mistake of undersizing the outlet; by "overpressure, I'm only talking about a TINY FRACTION , just a few Pascals, of difference; more will make it uncomfortable to be there and cause a loss of air flow. You want enough air changes per hour to keep things fresh... Steve
With air handling, slower = quieter, hence that recommendation.
I would put a filter ahead of the input to the blower, then put the blower on the INLET side of the studio; this will require longer and better absorbed ducting, because there is a slight noise penalty (not sure how much) due to the noise source being "upwind" of the studio - however, the plus side is that this will give you a slight positive pressure in the studio, so that every time you open the door you will "sweep" some of the dust OUT of the studio instead of sucking it in.
Rod prefers to have fans DOWN stream because of the extra noise possibility; I've always had problems keeping things dusted, so my idea is to increase duct length/size/number of turns to compensate for the slight diff in noise, and keep the benefit of a slightly pressurized room.
Don't, however, make the mistake of undersizing the outlet; by "overpressure, I'm only talking about a TINY FRACTION , just a few Pascals, of difference; more will make it uncomfortable to be there and cause a loss of air flow. You want enough air changes per hour to keep things fresh... Steve