greenhouse vent fan

Move and refresh the stagnant air flow in your greenhouse or Greenhouse Vent Fan building to make a healthier and more productive growing environment. These greenhouse exhaust enthusiasts are great for reducing plant and employee heat tension. Our exhaust enthusiasts provide exceptional ventilation for high tunnels and frosty frames. Create a cooler more comfortable growing environment, that may directly contribute to productivity, quality and profitability for your greenhouse business. Exhaust fans also works great in workshops and buildings.

The concept of cooling a greenhouse with thermal buoyancy and wind goes back to the start of controlled environment. All greenhouses built prior to the 1950's had some kind of vents or louvers that were opened to allow the excess heat to flee and cooler outside air to enter.

When polyethylene was developed with large sheets covering the whole roof, putting vents on the roof proved difficult. Engineers after that came up with the concept of using followers that attract outside air flow 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 flow movement is needed.

Growers with hoophouses possess discovered that roll-up sides work well for warm season ventilation. Both manual and motorized systems can be found. A location with good summer season 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 are powered by the principle that warmth is removed by a pressure difference created by wind and temperature gradients. Wind plays the major role. In a smartly designed greenhouse, a wind acceleration of 2-3 miles/hour provides 80% or more of the ventilation. Wind moving over the roof creates a vacuum and sucks the heated surroundings 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 top of the vent.