Best Ways to Keep your Greenhouse Cool
What temperature is too high for your greenhouse?
In general, any temperature above 90 degrees Fahrenheit (32 degrees Celsius) is too hot for your greenhouse cool. It is suggested that you do all necessary to keep the temperature of your greenhouse below this level. If you live in a region where temperatures regularly reach 100°F (38°C), this may become a genuine chore.
If the temperature in your greenhouse begins to rise rapidly in the summer, you’ll need to take appropriate measures to keep the ideal circumstances for your plants.
Ways to keep your greenhouse cool in summer
Regardless of how hot it gets in the summer, you can give your plants exactly what they need. The amount of cooling you’ll need is generally determined by the plants you’re cultivating and where you live.
1. Install a thermometer
First and foremost, if you don’t already have one, you should get one. This will assist you in keeping track of the temperature in your greenhouse. To guarantee optimal growth, use a standard thermometer to monitor your temperature.
2. Ventilation for great airflow inside the greenhouse
A ventilation system is required in every greenhouse. So, before you consider any additional cooling options, make sure your greenhouse has adequate ventilation. Properly positioned air vents, such as roof windows and louver vents, can help.
During periods of extreme heat, the temperature inside your greenhouse will typically exceed the outside temperature by 10-20°F. This is not a favorable situation for your plants. To keep things cool at this point, you can use either a natural or mechanical ventilation system.
To triple the airflow, just utilize side and base vents in addition to roof vents for natural ventilation. Allowing more cold air in by leaving your doors open is also a good idea. Because you don’t have to be home to open the vents, automatic vent openers can help keep your greenhouse cool. They have wax-filled pistons that automatically open or close depending on the temperature. You can use them to help sustain plant growth and boost ventilation.
If you have a medium or large greenhouse, or if the temperature outside is too hot, natural ventilation may not be enough.
This is why mechanical ventilation, such as the use of exhaust fans, is required. A good ventilation system will aid in the removal of hot air and the introduction of cooler air into your greenhouse.
3. Using greenhouse fans
Moving air around your greenhouse will help to cool it down slightly. Keep in mind that it will continue to use air from the inside or outside. So, if the temperature outside is 90°F, don’t expect your greenhouse to cool much below that if you solely use an exhaust fan to cool it.
When it comes to fan systems, there are various alternatives. However, there are a few things to think about before installing a fan system.
To begin, determine the ideal fan size for your greenhouse. You’ll need to figure out what ventilation rate is best for your structure. You could hire an expert to assist you with this. Up to an 8-foot height, fans should deliver one air exchange every minute.
Another important consideration is the location. Because hot air rises (for exhaust fans), you should place your fan near the top of the structure so that the airflow is above the plants. The hot air is blown out using exhaust fans. The intake shutter vent (louvered vent) should then be placed on the greenhouse’s opposite side. It should be put near the bottom so that colder air may be drawn in.
Airflow is also increased by combining a normal greenhouse fan with louver vents. You can place them behind the fan to allow the fan to bring cooler air in from outside, or you can place them at the top of any wall to allow hot air to escape.
It’s also critical to maintaining your fan systems on a regular basis. Cleaning fan blades, belts, and motors are simple procedures that can extend the life of your fans. If you live in a hotter climate, you may need more efficient cooling methods such as evaporative cooling.
4. Greenhouse Cool with evaporative systems
Evaporative cooling systems are a cost-effective and efficient cooling option. They cool your greenhouse by 10-20 degrees by evaporating water with heat! When the relative humidity is low, they work better. Fan-and-pad cooling systems are the most typical evaporative coolers. They work by sucking warm air into the greenhouse and chilling it down with the pads.
A fan-and-pad evaporative cooler collects water on a pad using an above water source and a gutter. Fans are frequently placed on either side of the pads to bring warm air into them. As a result, the pads are kept wet at all times, and the water transforms from liquid to gas and absorbs the heat.
5. Install a misting system or a fogger
Evaporative coolers are similar to these cooling technologies. They lower the temperature more quickly and to a greater extent. If you reside in a cooler climate, a mister/fogger is a gentle choice that will do the trick.
Misters and foggers use nozzles to spray water droplets into the air, which cools the area. The temperature drops as the water evaporates. Both methods work the same way, except foggers produce smaller droplets and have a higher cooling capacity.
6. Damping down
Another way to keep your greenhouse cool is to dampen it down. It works in a similar way to misting. Even in extreme temperatures, it aids in keeping plants cool. This approach works by increasing humidity, allowing plants to cope with higher temperatures. Wetting hard surfaces, such as walkways and staging within the greenhouses, is a simple way to accomplish this.
Moisture levels rise when the water evaporates, which helps keep pests at bay. You can dampen your greenhouse as often as you want, but be careful not to overdo it when it’s very hot.
7. Water your plants adequately
Appropriate watering is required to keep your plants thriving and healthy. Proper watering keeps plants cool and reduces stress. How? Plants are kept cool via transpiration, which involves the loss of moisture through the leaf pores.
8. Install a portable air conditioner
Another wonderful solution for cooling large greenhouses is a portable air conditioner. They are both cost-effective and energy-efficient. The majority of them include a dehumidifier as part of the package.
As a result, they’ll assist keep your greenhouse cool while regulating humidity levels. Furthermore, farmers with associated lean-to greenhouses can easily vent their air conditioners into their greenhouses. Unfortunately, air conditioners are fairly expensive, so this choice may not be suitable for you if you are on a tight budget.
9. Use plants strategically
Another natural way to keep your greenhouse cool in the summer is to use a fan. Plants are, first and foremost, natural evaporative coolers. Plant large-leaved plants like grapevine and fig trees in your greenhouse to keep it cool.
The big leaves to aid in the transpiration of moisture and provide shade to the soil. Now you can keep the temperature down, shade your soil, and eat juicy fruits, which is pretty cool, right?
What’s more, guess what? Plants can also be used to provide shade for your greenhouse. That’s right, merely erecting your greenhouse near a deciduous tree will provide you with all of the solar protection you require.
Deciduous plants can help you safeguard your greenhouse all year long. In the winter, it loses its leaves and gives the light in such a chilly season. However, its leaves will regrow in the spring, providing you with the needed shelter from the blazing sun.
10. Creating shade for less sun exposure for Greenhouse Cool
Shade cloths and curtain systems are an easy and inexpensive way to add shade to the greenhouse, which helps to cool it down slightly. Expect a small drop because you’re not covering it with a solid roof.
These clothes might also come in handy if your plants are scorched by the sun. Internal curtains can be easily installed and closed as needed. External shade cloths can be draped over the entire greenhouse, providing significantly better protection from the sun’s heat.
Shade cloths for greenhouses are available in a variety of colors and densities (measured in percentages) (e.g. 30 and 90 percent shade). These percentages represent how much light is blocked from entering the greenhouse. Now it’s up to you to decide which density to employ.
This is dependent on the climate in your area, as well as the design of your greenhouse and the light requirements of your plants. Vegetables should be kept in light shades of 30-50 percent because they still require appropriate sunlight. Other ordinary plants can benefit from a 50% gradient, and ferns and orchids can benefit from a higher shadow.
Curtain systems can improve your greenhouse environment and reduce plant stress to a considerable amount. Make an effort to use certain materials that are long-lasting. Polypropylene, polyolefin, and aluminum are some of the materials you can use. The latter two materials also help to reflect heat.
Why should you keep your greenhouse cool in summer?
If you’ve gone through the strategies above and aren’t sure why you should devote so much time, effort, and money to this, let me explain the hazards.
You will jeopardise all of your hard work if you do not maintain your greenhouse cold. How? When it’s hot outside, your plants are more vulnerable to pests and illnesses. In extreme temperatures, they can also grow stressed, wilt, or dry out.
They may even stop creating new growth in extreme circumstances. And you already know what it means: low or non-existent yields! Most plants, especially vegetables, thrive in cool(ish) temperatures; exceeding this temperature limits their health and growth.