by Steve Bogash, Horticulture Extension Educator/Researcher | Penn State University Presented at the 2015 Minnesota Statewide High Tunnel Conference.

1. MECHANIZATION OF VENTILATION
IN HIGH TUNNELS
Steve Bogash
Horticulture Educator / Researcher

2. High tunnels are designed to be low
tech, low input, structures why
complicate them?

3. Mechanizing your tunnel:
• Temperatures within tunnels change rapidly.
– Without some automatic temperature control you must
constantly adjust roll up sides, roof and gable vents.
– Adjusting to temperature shifts is most important at the
season fringes when tunnels are most critical.
– One of the most significant disease controls is keeping
humidity under control.
– Flower abortion occurs when air temps get over 92-95F.
– Fruit quality can be enhanced with greater temperature
and humidity control.

4. Types of enhanced ventilation
• Motorizing roll-up sides
• Powered fans and louvers
• Gable end vents
– Thermostat controlled
– Manually adjusted
• End wall / door innovations

13. Coal furnace

14. Air pollution damage from coal

17. Temporary end wall during construction

23. Large removable door panels

29. Sliding doors vs. hinged

30. IR and diffusion plastics

32. Removing entire end

33. Mid-greenhouse vent PSU Tunnel Town

38. 12 volt solar powered
gable end fans

41. Is vertical redistribution next?

42. Interesting home built

43. THANK YOU
PLEASE SEND ME YOUR MECHANIZATION
IDEAS!
Steve Bogash
Horticulture Educator / Researcher