Turbine Ventilator

[MagicJS]

Hi, I'm working on a five story residential building. For bathroom exhaust, the client asked me to use ceiling mounted exhaust fans in bathrooms and a wind powered turbine ventilator on the roof instead of a roof fan. The shaft are straight runs, a few offsets on top floor.

Has anyone else done something like this. Will the ceiling fan and ventilator be enough or should I insist on installing roof fans

Thanks.

 

[MikeHalloran]

Turbine vents do nothing in still air. You will not like the results.



Mike Halloran
Pembroke Pines, FL, USA

 

[willard3]

A turbine and exhaust fan in series with a fan will also operate very oddly as the wind speed varies.

Some fan blade types will surge or choke when the ventilator is making much pressure.

Don't do it.....

 

[Wolfie82]

I have never heard of this type of system. It sounds like a bad idea to me and I wouldn't do it. Ceiling mounted exhaust fans typically don't develop much static pressure and the air will have trouble traveling 5 stories when the turbine is not turning.

If you do use this system, I would recommend using a fan with a built-in back-draft damper. Why does the owner want this type of system? Is he trying to save energy?

 

[MagicJS]

The owner is used to rehabing 3 story brownstones with this method. I'm calling for 50 CFM ceiling fans with 0.55" static and backdraft dampers. Even without a ventilator, I think the static combined with stack effect should be enough to push air out, right?

MagicJS

 

[willard3]

snip
I think the static combined with stack effect should be enough to push air out, right?
snip

It will if the duct is the right size. Stack effect will also depend upon your local climate.

If the outside air temp is lower than the inside temp, there will be stack effect from thermal buoyancy.

Also, be careful with fan pressure capacity....0.55" WC is outside the range of many small fans.