The Naked Scientists

The Naked Scientists Forum

Author Topic: What are the prism-shaped rotating objects seen on roofs?  (Read 4511 times)

Andrew Norton

  • Guest
Andrew Norton  asked the Naked Scientists:
   
Hi Chris
     
What are the shiny prism shaped things found on some buildings and which rotate? Is this to deter the birds from defecating on the roof
tiles?

Kind regards

ANDREW NORTON  

What do you think?


 

Offline Chemistry4me

  • Neilep Level Member
  • ******
  • Posts: 7709
    • View Profile
What are the prism-shaped rotating objects seen on roofs?
« Reply #1 on: 17/04/2009 01:32:26 »
What's this? I have never seen such a thing.
 

lyner

  • Guest
What are the prism-shaped rotating objects seen on roofs?
« Reply #2 on: 17/04/2009 11:06:13 »
If they are on chimneys, they could be rotating cowls - to stop back draft down the flue. New ones can look shiny for a few months / years.
 

Offline cedar_tree

  • Jr. Member
  • **
  • Posts: 28
  • General pseudoscientist
    • View Profile
What are the prism-shaped rotating objects seen on roofs?
« Reply #3 on: 18/04/2009 03:26:59 »
they are wind turbine vents, or its an 3D space observatory
« Last Edit: 18/04/2009 03:30:33 by cedar_tree »
 

Offline chris

  • Neilep Level Member
  • ******
  • Posts: 5335
  • Thanked: 65 times
  • The Naked Scientist
    • View Profile
    • The Naked Scientists
What are the prism-shaped rotating objects seen on roofs?
« Reply #4 on: 18/04/2009 12:36:30 »
Yes, they are rotating cowls that point into the wind such that the open (vent) side is always facing downwind. This prevents the wind from blowing back down the chimney, stopping smoke or flue-gas build-up in the house or building.

They are quite popular in South Africa. Our next door neighbour (who is from South Africa originally) has one, and when I was in Grahamstown for SciFest I noticed quite a few houses using them. I presume there are quite a few windy days there?


Chris
 

The Naked Scientists Forum

What are the prism-shaped rotating objects seen on roofs?
« Reply #4 on: 18/04/2009 12:36:30 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums
 
Login
Login with username, password and session length