Ridge and Eave Ventilation
Ridge vents and eave vents are an essential part of any functioning greenhouse with a functional, passive ventilation system. When the air is not vented, it becomes stagnant, stale, and allows diseases to breed. To help prevent this, ridge vents and eave vents need to be installed in a greenhouse.
The systems act the same way, but on different areas of the greenhouse. Both units are operable panes of glass enclosed within a frame separate from the greenhouse’s structural frame. The vent will open by a motor which is moisture-resistant, or by manually with the aid of a rod operator. It opens to a specified angle and allows air into the greenhouse. Screens come with both systems to prevent insects and leaf debris from entering the greenhouse.
The ridge vent is very important to the greenhouse. Hot air rises and accumulates at the peak of the greenhouse. As the ridge vents are opened, the hot air escapes and fresh, cool air enters. The ridge vents also allow the air to circulate. If there is a breeze outside, it will enter the greenhouse and help circulate the air; this reduces the spread of disease. If your greenhouse is utilizing intake louvers/exhaust fans, the ridge vents will be used in removing the hot air, so the new air can enter the greenhouse.
The size of the greenhouse will determine the size of the venting systems, but a general rule of thumb is the total venting area should be between 25-30% of the glazed greenhouse area. Solar Innovations® ridge vents are typically manufactured to a 27″ diagonal on the slope. They are available in various bay widths up to 48″ with a total overall length up to 24′. Our eave vents are typically 27″ high and are available in various bay widths up to 48″ with a total overall length up to 24′. Eave vents will match the bay widths of the structure; however, numerous custom designs are available.
Both ridge vents and eave vents can span multiple bays. The best design is to line-up the eave vents with the ridge vents to help with cross ventilation. The units can be set up to a timer, say every fifteen minutes the vents will open. Another option is to set them on a temperature timer. When the greenhouse reaches a pre-determined degree the vents will open. Rain sensors can be added to the units so that when snow or rain hits the vents they automatically close. If your greenhouse utilizes an environmental control system, the ridge vents can be programmed into your specific system. Without the ventilation your greenhouse will be a glass box filled with stagnant air.
The diagrams below show the benefits of ridge and eave vents in both our lean-to and double pitch structures. The accumulated hot air is released with a ridge vent. This provides a cooler environment as well as proper circulation. Hot air builds up at the top of the structure without a ridge vent. This prevents fresh air from entering the structure, which, in turn, delays the cooling process and limits air circulation.
In addition to our ridge vents, Solar Innovations® offers hooded cooling fans. The fan is installed near the ridge of a structure. The placement allows the fans to remove the hottest air at the ridge first and then continue to cool the rest of the space. The unit is operated by a manual control or thermostat, making it suitable for most applications. It comes standard in Bronze, White, and Sandstone, includes a wall mounted thermostat, and is glazed in-system like a piece of glass.
In-system skylights are the perfect solution if venting is necessary in the roof of a low pitch Solar Innovations® structure (below 3/12 or 14° roof pitch.) In-system skylights serve a purpose similar to that of ridge vents. The skylights feature a higher profile and a low pitch seal to ensure protection against leaking. These skylights can be operated either manually or with a moisture resistant motor. (One motor can operate up to a two-bay skylight. Three- and four-bay skylights will require two synchronized motors.)
An in-system skylight helps ventilate the greenhouse. Without ventilation, a greenhouse is just a glass box where temperatures can reach over 100 degrees, and will kill your plants. Hot air always rises and accumulates at the ridge of the greenhouse. Air can become stagnant and will promote the spread of disease and fungus. This air needs to escape to allow your plants to continue growing. The in-system skylight will open and allow the hot air to escape while bringing in new fresh air. The new air will circulate through the greenhouse, which promotes healthy plant growth.
The skylights are made from thermally broken aluminum, which does not rot, rust, warp, or require constant finish maintenance. The models are thermally enhanced to match the greenhouse framework. Each skylight is available in seven standard colors and two anodized frame finishes or any required custom color. Insect screens come standard with the skylights, which allow air into the greenhouse but prevent unwanted insects from entering. The insect screens can also keep in the good insects you may use for bug control, such as ladybugs or wasps.
In addition, Solar Innovations® operable skylights can be retrofitted for existing glass structures or other roof applications.