Your greenhouse needs vents to allow fresh air to move in, but you should also have some kind of circulation fan to keep the air moving throughout the entire greenhouse so that it will reach all of your plants. Many people fail to realize how ventilation affects pests within greenhouses.

How much airflow does a greenhouse need?

Provide adequate fan capacity For an efficient system, the total fan capacity should be about two times the floor area. For example, in a 30′ x 100′ greenhouse, the fan capacity should be 30′ x 100′ x 2 = 6000 cfm.

Should you ventilate greenhouse?

Plants grown in glasshouses, conservatories, plastic greenhouses, polytunnels and garden frames, especially in the summer months, all require adequate shading and ventilation.