Move and refresh the stagnant air flow in your greenhouse or building to create a healthier and more productive growing environment. These greenhouse exhaust fans are great for reducing plant and worker heat tension. Our exhaust followers provide exceptional ventilation for high tunnels and frosty frames. Create a cooler Greenhouse Exhaust Fan convenient growing environment, that may directly contribute to productivity, quality and profitability for your greenhouse business. Exhaust followers also functions great in workshops and structures.
Move and refresh the stagnant surroundings in your greenhouse to create a healthier and more productive environment. These exhaust & circulating fans are great for plant development. Create a cooler convenient growing environment, that may directly contribute to efficiency, quality and profitability for your greenhouse business.
The concept of cooling a greenhouse with thermal buoyancy and wind goes back to the start of managed environment. All greenhouses built prior to the 1950’s experienced some type of vents or louvers that were opened to allow the excess heat to escape and cooler outside surroundings to enter.

When polyethylene originated with large sheets covering the whole roof, putting vents on the roof proved difficult. Engineers then came up with the idea of using followers that pull outside atmosphere through louvers in a single endwall and exhaust it out the opposite end. With thermostatic control, this is, and still may be the accepted way for cooling many structures where positive air movement is needed.

Growers with hoophouses possess discovered that roll-up sides work well for warm season ventilation. Both manual and motorized systems are available. A location with good summer breezes and lots of space between houses is needed. It helps to have greenhouses made with a vertical sidewall up to the height of the attachment rail to reduce the amount of rain that can drip in.

Greenhouses with roof and sidewall vents operate on the principle that temperature is removed by a pressure difference created by wind and temperature gradients. Wind plays the major part. In a well designed greenhouse, a wind velocity of 2-3 kilometers/hour provides 80% or even more of the ventilation. Wind moving over the roof creates a vacuum and sucks the heated atmosphere out the vent. If sidewall vents are open up, cool replacement air enters and drops to the ground level. If the sidewall vents are closed, cool air enters the bottom of the roof vent and the heated are escapes out the top of the vent.