Forward curved fan can backspin??
Forward curved fan can backspin??
(OP)
Hi all,
Does a forward curved centrifugal fan backspin with air flow being pumped through it in the direction that it would ususally move air? I have heard that backward curved fans do this, but i dont know about forward ones!
cheers
Does a forward curved centrifugal fan backspin with air flow being pumped through it in the direction that it would ususally move air? I have heard that backward curved fans do this, but i dont know about forward ones!
cheers





RE: Forward curved fan can backspin??
The way we build has a far greater impact on our comfort, energy consumption and IAQ, than any HVAC system we install
RE: Forward curved fan can backspin??
If air is going through it forward with the motor on and correct rotation, air going backward with motor off spins it backward....'tis the nature of the beast.
RE: Forward curved fan can backspin??
so just to get this 100%, forward curved with air forced (by another fan say) in the usual direction of flow (with power off the fan motor) the resulting fan rotation will be??? (normal or reverse to usual spin?)
RE: Forward curved fan can backspin??
If the air enters from the scroll outlet without swirl and the fan is off, rotation will be backward on all fan types.
Backward = reverse of normal flow.
RE: Forward curved fan can backspin??
If it was a plug fan (no shroud/volute) it would be simple. It will act like a turbine with air forced into the inlet. It would spin backwards.
But a centrifugal fan with the volute forcing air only out the top ~90° of the fan's full rotation might cause a different effect and could drag the fan in the forward direction.
Hopefully I didn't just add to the confusion.
RE: Forward curved fan can backspin??
so who is gong to do the experiment to confirm the theory???? Nothing beats empirical proof.
Anyone already done this experiment?
RE: Forward curved fan can backspin??
The way we build has a far greater impact on our comfort, energy consumption and IAQ, than any HVAC system we install
RE: Forward curved fan can backspin??
RE: Forward curved fan can backspin??
I suppose with enough air forced through a unit with a larger belt driven blower, The inertia of the heavier wheel and the belt tension would be over come and these wheels would spin backwards as well.
The way we build has a far greater impact on our comfort, energy consumption and IAQ, than any HVAC system we install
RE: Forward curved fan can backspin??
RE: Forward curved fan can backspin??
The way we build has a far greater impact on our comfort, energy consumption and IAQ, than any HVAC system we install
RE: Forward curved fan can backspin??
RE: Forward curved fan can backspin??