The Ventec chimneys were designed with animal ventilation in mind. They are made of H.P.D.E. plastic to ensure a long lasting product without cracking, rusting or changing colour.
The flat top helps prevent the infiltration of precipitation as illustrated. The legs were placed on the outside so if they accumulate ice when thawing, the ice and water would stay on the outside and not drip in. The chimneys are also insulated reducing condensation to a minimum.