Nexus has a long history of being innovative with different techniques to cool a greenhouse from natural to mechanical ventilation.  Natural ventilation has garnered a larger stake with the open roof houses and atrium vents. Traditional fan and pad systems are still common in areas that have temperatures and humidity that are conducive to evaporative cooling.

Natural Ventilation - Roof Vents
Natural Ventilation - Side Vents - Guillotine
Natural Ventilation - Side Vents - Rack & Pinion/Curtains
Mechanical Ventilation