Move and refresh the stagnant air flow in your Greenhouse Vent Fan greenhouse or building to create a healthier and more productive growing environment. These greenhouse exhaust enthusiasts are great for reducing plant and worker heat stress. Our exhaust followers provide exceptional ventilation for high tunnels and cool frames. Create a cooler more comfortable growing environment, which can directly contribute to efficiency, quality and profitability for your greenhouse business. Exhaust followers also works great in workshops and structures.
Move and refresh the stagnant air flow in your greenhouse to create a healthier and more productive environment. These exhaust & circulating fans are great for plant growth. Create a cooler more comfortable growing environment, which can directly contribute to efficiency, quality and profitability for your greenhouse business.
The idea of cooling a greenhouse with thermal buoyancy and wind dates back to the start of managed environment. All greenhouses constructed prior to the 1950’s had some form of vents or louvers that were opened to enable the excess heat to flee and cooler outside atmosphere to enter.
When polyethylene originated with large sheets covering the whole roof, putting vents on the top proved difficult. Engineers after that came up with the idea of using supporters that attract outside atmosphere through louvers in one endwall and exhaust it out the opposite end. With thermostatic control, this is, and still is the accepted method for cooling many structures where positive atmosphere movement is needed.
Growers with hoophouses have discovered that roll-up sides work well for warm time of year ventilation. Both manual and motorized systems are available. A location with good summer breezes and plenty of space between houses is needed. It can help to have greenhouses designed with a vertical sidewall up to the height of the attachment rail to lessen the quantity of rain that may drip in.
Greenhouses with roof and sidewall vents are powered by the principle that heat is removed by a pressure difference created by wind and temperature gradients. Wind plays the major part. In a smartly designed greenhouse, a wind rate of 2-3 kilometers/hour provides 80% or more of the ventilation. Wind moving over the roof creates a vacuum and sucks the heated air flow out the vent. If sidewall vents are open, cool replacement air enters and drops to the ground level. If the sidewall vents are closed, great air enters underneath of the roof vent and the heated are escapes out the very best of the vent.