Tagged: energy efficient

greenhouse ventilation

Greenhouse Ventilation

Greenhouse Ventilation 

Vents VS Exhaust/Shutter System

greenhouse ventilation

There are many factors to consider when greenhouse shopping; Insulation, glazing material, space, foundation, heat and of course greenhouse ventilation. And if you are planning on growing year round you want to make sure to choose the most energy efficient structure because heating in the cooler months can be expensive – This is where great insulation can reduce energy costs.

greenhouse ventilation
Example of roof vent
Greenhouse ventilation
Example of roll up sides

Manual or automatic roof vents have their advantages and disadvantages. If the greenhouse is designed very well then aerodynamics have been considered and the roof vents will be placed in the perfect position for wind to pull air out while still circulating air through the greenhouse. Placement of the greenhouse is also very important for wind to catch on the ridge of the greenhouse and create a vacuum type air movement. A large circulation fan or multiple fans will be required in the interior of the greenhouse and will aid in fresh air exchange. Some larger or commercial greenhouses offer a roll up design that allows for the sides of the greenhouse to be completely open to the outside. Now, if you are concerned about pests this might not be the best option for you because generally with open air vents many of them are needed and screening them can be difficult, if not impossible. Maintenance can give you trouble as well. If you do not have the time to go open the manual vents, do not have the ability to climb a ladder for high roof vents, or have limited budget for automatic vents then an alternative option should be considered. For a very small/beginner greenhouse or a small lean-to style with a low insulation value these type of vents are appropriate. The higher the insulation value of the greenhouse glazing material the stronger ventilation you will need.

 

greenhouse ventilation
220V power panel

Thermostatically controlled ventilation is very popular and with supplemental air circulation can be most efficient. Sunglo uses exhausts fans and motorized intake shutters controlled by a thermostat with the option to hook up to a heater as well; we call them power panels and include other electrical items too. So if you prefer your greenhouse to remain between 50° and 75° all you have to do is set the thermostats for the ventilation and heater to turn on and off automatically. The exhaust fan and shutter are synchronized to open at the same time. The motorized shutter opens to allow fresh cool air into the greenhouse while the exhaust fan starts to spin and expel the used hot air that has risen inside the greenhouse. Sunglo’s basic system is rated to exchange fresh air throughout the greenhouse once per minute; providing you with a system that cools rapidly. The basic system is included with every Sunglo greenhouse. The exhaust fan(s) are placed as high as possible on one end of the greenhouse and the

greenhouse ventilation
Schaefer exhaust fan and shutter
Greenhouse ventilation - Automatic opener
Automatic vent opener for Sunglo vent

shutter(s) are placed as low as possible on the opposite end. This allows for the best possible circulation throughout the entire greenhouse. There are many brands to choose from but either aluminum, steel, poly or fiberglass options are available each with different pros, cons, sizes and pricing. We include poly exhaust fans and shutters with our greenhouses but any type is available for upgrade. Automatic vent openers are available for the gable end manual vents on our greenhouses and will increase air circulation as well. They do not use any electricity. These automatic openers are controlled by a wax piston. By twisting the piston left or right sets the degree to which it opens. These automatic openers are specially important in areas where the climate stays consistently at or over 80 degrees. By setting up a circulation fan inside the greenhouse and setting the automatic openers to open before the ventilation system starts will save you electricity usage. Sunglo also offers a variety of atmospheric controls. If you would like to view some of the ventilation products Sunglo offers please visit the Schaefer website or give us a call with your inquiry.

 

greenhouse ventilation
Sunglo greenhouse – Front with intake shutter and back with exhaust fan

Learn more about summer climate control here.

If you are interested in adding ventilation to your greenhouse or would like to discuss options or have questions about anything please give us a call at 425-251-8005 or e-mail to info@sunglogreenhouses.com.

Energy saving tips – In your greenhouse

Here are a few energy saving tips:

Energy Saving Tips

Reduce air leakage from the greenhouse –

Small cracks and loose glazing materials can cause unwanted air to enter or escape from your greenhouse. Obviously both will affect the efficiency of any heating system you have in place. But fixing areas around the doors and vents that are not air tight can help stop unwanted air flow. Caulking holes or lining parts of the frame and weather stripping around the door can make a big difference. Shutting your fans off during the winter and covering them with a thick plastic will help keep your greenhouse regulated in the winter months. And always fix any holes or broken panels as soon as possible. If you have a Sunglo you can call 1-800-647-0606 for any replacement parts!

Use a double layer glazing system –

Double layered glazing material can be beneficial, if it is done the correct way. Our greenhouses have an inner corrugated panel that creates a 1.5” dead air space keeping it exceptionally insulated. To see how Sunglo’s unique glazing system works click here.

Install windbreaks –

Windbreaks are important in high wind areas because it prevents the cold wind from hitting the greenhouse therefore cooling it down. Building a mini fence or even planting shrubbery around the base of your greenhouse is effective. Some gardener’s plant small trees around their greenhouse, it not only looks pretty but will help keep the wind at bay. Whatever you decide to use make sure it stands mid-level to your greenhouse so it doesn’t block the sun. If you already have some tree cover in your yard or near the greenhouse than your in luck! No planting for you!

Use a shade cloth –

Shade cloths are wonderful for high temperature areas. They are used during the hottest time of the day to reduce thermal solar radiation. Sunglo carries a wide variety of sizes and they can be mixed and matched to perfectly fit your greenhouse. For more information on shade cloths click here.

Use your heat wisely –

To calculate what type of heater you’ll need for your greenhouse there is a simple formula. Take the temperature you want the greenhouse to stay at (let’s say 50) and the average winter temperature in your area (how about 20) and subtract them (equals 30). Next you multiply the temperature difference by the surface area of your greenhouse (8×10 greenhouse is 276 X 30 = 8280). Now you multiply your answer by your greenhouse materials U value. For a Sunglo you would multiply 8280 X .75 = 6210 BTU’s(.75 is Sunglo’s U value). This means you need to find a heater that has exactly or over 6210 BTU’s to efficiently heat your greenhouse. Using the correct heater will ensure thriving plants and not use unwanted electricity. To see this formula again and more in depth information on BTU requirements check out this post. Click here.

For more information on saving energy visit PSE.com