Exhaust fan Eplilog legend 36

[Sandy Henry]

I'm not happy with air flow thru laser. Considering adding another exaust fan similar to the one provided by Epilog - to double my air flow. A friend has offered a fan that would move more air than the double fan system and it has variable speed control. Any thoughts or advise before I start pulling everything apart? ! Thanks, Sandy

[Joe Pelonio]

With the variable speed control I'd say go for it. The exhaust system I used in a commercial space with 25' run worked out great, but when I moved it to my home shop with only 3' I have had some issues with small, light parts being sucked out. Too much velocity is not good either, but hopefully you can strike a good balance.

[Sandy Henry]

Thanks Joe, I'll let you know if it works well.

[Richard Rumancik]

Sandy, were you thinking of running one blower on each port on the laser? It might work, but fans in parallel can be very tricky to get working properly. Especially if they are not 100% identical. You can also get oscillations in some situations which may be difficult to resolve.

Were you planning separate exhausts out of the building? Or were you thinking of a wye on both the inputs and outputs? Also, don't assume that two blowers in parallel will double your airflow. Blowers in parallel can be quite complicated and it is not a linear relationship.

Personally I think you will be much better off using a single blower.

When you say you will "double" the airflow with the variable speed unit, I assume you mean it is double at the same static pressure (preferably measured at about 4" or 6" water gage). If the two blowers are being compared at zero pressure, that is not really a meaningful comparison. eg. if blower A can deliver 500 cfm max and blower B can deliver 1000 cfm max (the maximum occuring at zero pressure) you cannot say blower B will deliver twice as much air as blower A when it is installed in a laser system.