Ventilation is one of the most important ‘things’ that you learn about for a greenhouse to help you be successful. If you do not pay particular attention to your greenhouse ventilation, your greenhouse could become too hot or too humid for your plants and flowers to grow properly. One of the most important features about a ventilation system is to make sure the air changes within the greenhouse to offer the plants the best mix of carbon dioxide to absorb. A complete mix of air in the greenhouse would be the circulation of new air about every three or four minutes in the inside of the greenhouse to keep the temperature at its lowest during the summer months. When summer air stands still in the greenhouse it will rise in temperature because of the panels absorbing the sunlight.
In addition to the fans in your greenhouse you should add vents to your greenhouse structure. Vents in the roof and in the sidewalls will help the air flow for circulating during the hottest of summer months. You can use roof and side vents to cool the greenhouse in the spring and fall months without the use of circulating fans to keep your electric bills lower.
During the time of the year when the cold air and winter months are creeping up, opening and closing your vents allows the plants and flowers to become accustomed to the colder climate while still being productive but yet not freezing. Using fans in combination with the vents during the hottest months of the growing season will also circulate hot spots or hot air so that your plants won’t wilt and burn off. During the summer months there are many hobby gardeners who use automatic ventilation systems to open and close their vents. If you are away for a couple of days and do not open your vents you could come home to a greenhouse filled with wilted and dried out plants.
Your ventilation needs and circulating air needs during the winter months are less critical. You should learn about the automatic watering systems, ventilation systems and other automatic systems that provide the stable environment for your plants, if you are a hobby gardener who is always on the go so that you can best benefit from your greenhouse.