Tube systems to ventilate calf facilities have a plastic tube with a fan blowing fresh, clean outdoor air into the tube. Tubes commonly are made of either polyethylene or PVC
Calf Barn Ventilation – The Dairyland Initiative
Exacon Calf Barn Ventilation - Dairy Lane Systems - Air Tube
Calf Barn Ventilation - J&D Manufacturing
Ventilation and Heat Abatement – The Dairyland Initiative
4dBarn® Ventilated – ventilation system design for for all calf barns
Sun-North Systems Ltd - Fresh Air Positive Pressure Air Tube
Livestock Ventilation / Tube Systems — Agrivent Ltd
Cow housing, South West England, UK
Tube ventilation for calf barns work
A review of calf housing