Greenhouses are natural hot houses that trap heat and produce ideal climates for plants that require regulated conditions to develop in. Having a robust ventilation control system in your greenhouse is critical to exchange stale air with fresh air throughout the summer months when temperatures skyrocket. Whether you possess a greenhouse or are considering purchasing or building one, it is critical to understand what is happening outside and inside the growing environment. In this post, we will answer some frequently asked questions concerning greenhouse ventilation and assist you in determining the best solution for you.

You must have a weather station, whatever automation solution you use for your grow system. Weather stations gather data about the environment outside your greenhouse. They assist you in monitoring crucial metrics such as temperature, humidity, sunlight levels, and rain and wind.

A weather station will use sensors running INSIDE and OUTSIDE the greenhouse to measure the environment.

Install your external weather station in a visible place. You'll need to clean it frequently to ensure accurate readings, especially if you live in an area prone to bird life, leaf fall, or other external variables.
Your data is just as good as your sensor, so invest in a long-lasting system that provides precise measurements.

Roof vents are a passive cooling technology that uses hot air convection. Roof vents are one of the most efficient ways to cool a structure, particularly in temperate climates. Hot air rises to the top of the greenhouse and exits through the vent, pulling in cool air from below. Open roof construction is adjustable; opening the vent will keep the greenhouse cold while closing the vent will retain heat. Open roof vents might be open-panel, retractable-film, flat-roof, or low-profile.

Bringing cooler outside air into the greenhouse during hot weather is cost-effective. Many farmers have found this strategy beneficial because it has reduced production time and created higher-quality plants.
Open roof vents will assist you in maintaining ideal temperature and humidity levels.
A roof with an open structure will let more natural light into the greenhouse.
Place mesh screen covers around exposed areas to keep unwelcome pests at bay. However, depending on the type of screen, this can lower the amount of air movement by up to 45%.

Side vents protect your plants while also increasing ventilation in the greenhouse. If your greenhouse plants are on a bench, roll up the side walls to the height of the bench and allow cold air to flow underneath, producing an excellent habitat for the greenhouse plants. Using side vents decreases the need for fans and electricity, lowering overall costs and making it a cost-effective solution.

According to research (Santorini 2005, Wang 1999), the most effective vent layout is a combination of roof and side vents, particularly in warmer areas at low altitudes.

Natural ventilation is a system in which the difference in temperature between the interior and exterior creates a buoyancy force that drives airflow. Warm air has a lower density than cold air and will rise above it, creating an upward air stream similar to that of a typical fireplace.

The following are some of the benefits of control systems for natural-driven ventilation:

It does not require wind and can be performed on hot summer days.
Natural ventilation offers a more steady airflow than wind ventilation.

The following are some of the drawbacks of natural-driven ventilation:

Natural ventilation is based on the temperature difference between the outside and inside.
The greenhouse's design has an impact on natural ventilation.

Wind blowing outside the greenhouse causes a tiny pressure difference between the windward and protected sides, allowing air to travel to the sheltered side. Wind-driven ventilation is most effective when the greenhouse vents are angled to take advantage of the prevailing winds. However, the wind's effect is minimal if side walls do not supplement roof vents. The wind effect is affected by the length and size of your greenhouse.

According to the American Society of Agricultural and Biological Engineers, the roof vent area should match the total sidewall vent area, and each should be at least 15 to 20% of the floor surface.

Roof vents should be hinged on both sides of the ridge, whereas side vents are often at bench height.

Because of the greater buoyancy effect and capacity of hot air to rise higher above the plants, taller greenhouses are easier to ventilate.

It's crucial to note that if your greenhouse is in a hot and humid climate, you may need to consider additional ventilation control equipment. Contact AutoVent today if you're ready to start talking about ventilation controller solutions for your greenhouse.