How do you keep a small greenhouse from overheating while the temperature rises? A greenhouse’s major function is to keep crops safe from the extremes of heat and cold, as well as pests. You should be prepared for a rise in greenhouse temperatures as the days grow warmer.
A poor-quality crop and increased vulnerability to insects and pests could result if this is left unchecked. It’s critical to maintain a consistent temperature in your greenhouse. While some crops may be able to withstand the heat, others are certain to succumb.
Learn more about how to keep your greenhouse cool by reading on.
What Are Some Ways to Cool Your Greenhouse?
The quantity of cooling you’ll require depends on where you reside. An effective cooling system for your greenhouse is essential if you reside in an area that experiences particularly hot summers. It’s possible to get by with just a ventilation system if you reside in a colder climate.
In cold greenhouses, passive or natural ventilation is one of the most commonly employed strategies. As a result of the fact that it is a low-cost way to cool greenhouses.
There is no need to spend a fortune on pricey greenhouse ventilation and temperature control systems. To maintain the room’s temperature, all you need is a vent to move air in and out.
In order to keep the greenhouse cool, natural ventilation relies primarily on wind pressure. Cooler air is drawn in through the vents and replaces the heated air that was before present.
Another vent is used to expel the greenhouse’s heated air. A few degrees are lowered by doing this. It’s an excellent way to cool the greenhouse.
Roof and side-wall ventilation are two of the most frequent passive ventilation methods used by humans. Experts estimate that roof ventilation is five times more effective than side-wall ventilation.. However, a greenhouse with a combination of the two can achieve maximum cooling.
Passive or natural ventilation is less expensive than active ventilation. The greenhouse is kept cool with the help of fans. They can be set up to pull cold air in and push hot air out of the greenhouse, or they can be designed to circulate the air within the structure.
To achieve the best results, the air should be pushed all the way through the greenhouse to avoid hot air packets. Fans should be placed on a higher surface in order to ensure this.
This is a better solution than putting the fans on the bottom of the enclosure. Place fans at least 10 feet above the greenhouse floor in areas where summer temperatures are higher.
When natural ventilation is no longer able to maintain the greenhouse’s temperature, the use of active ventilation is needed. Active ventilation, on the other hand, may necessitate more in the way of overhead and upkeep. Before putting in active ventilation in your greenhouse, make sure to keep these things in mind.
Evaporative cooling is another option for keeping greenhouses cool. This is a more involved method of cooling tiny greenhouses than the others.
Consequently, it will necessitate additional utility and maintenance costs. The heat in the air is utilised to evaporate the water in plants and other wet surfaces in this greenhouse cooling method.
The fan and pad approach is the most widely utilized evaporative technique. The cellulose pad is soaked with water by a pump in this arrangement. The fans on the other side of the cellulose pads pull the air inside via the wet cellulose pads, thus cooling the greenhouse atmosphere. At least 10oF to 20oF is lowered in the greenhouse as a result of this.
In order to maximize the effectiveness of evaporative cooling, it is important to know where you are currently located. As a result, this type of treatment is best used in places with drier and more humid weather conditions. In addition to natural ventilation, evaporative cooling can be used.
What Temperature is Considered Too Hot for Greenhouses?
In a perfect world, your greenhouse’s temperature should be between 80 and 85 degrees Fahrenheit. Also take into account the kind of plants you’re growing.
Anything beyond 90 degrees Fahrenheit is considered too hot and might harm your crops. Despite the fact that plants such as tomatoes are unable to survive in such conditions.
Where Should You Set Up a Greenhouse?
Orienting your greenhouse so that it receives as much early morning sun as possible is ideal if you live in North America. The east-facing orientation is another option, especially when the southern exposure results in some glazing.
Can I Put a Greenhouse in the Shade?
The optimal location for a greenhouse is one that is completely exposed to the sun. While solar-intensity lighting could be more convenient, it would be much easier for you to find ways to shade your greenhouse. If your greenhouse is going to be in the shade, you’ll need to find a location that isn’t too secluded.
Learn How to Cool a Small Greenhouse and Enjoy Greater Yields
You’ll be able to get better yields and higher-quality crops now that you’ve learned more about how to cool a tiny greenhouse. Inspect your greenhouse’s cooling system if any of your plants are showing signs of heat stress such as wilting, burned leaves, or drying foliage. Keep these greenhouse cooling strategies in mind to avoid any plant harm in the future.
7 Ways to Keep Your Growing Dome Greenhouse Cool
Even in the sweltering heat of summer, you can keep your greenhouse well-ventilated.
The purpose of a greenhouse is to collect and store heat. You don’t want them to get too hot, but they are inevitable. In the summer, the Growing Dome Greenhouse is meant to be as cool as the surrounding air, if not cooler.
In this video, Udgar explains to you seven ways to keep a greenhouse cool.
First – utilize Large Leaved Plants in strategic places…
Nature’s evaporative coolers are plants. Your greenhouse will stay cooler with a big number of plants, especially broad-leaved plants like this grapevine and these fig trees. Both edible, fruit-bearing, soil-shading, and evaporative coolers are found in the area.
Soil temperature can be kept at a comfortable level thanks to the big leaves. We have roughly 40 tons of soil in this 33-foot Growing Dome.
This dome would be significantly hotter if the 40 tons of soil reached 110° or 120° because it is naked dirt.
They help keep your greenhouse cool by allowing water to evaporate from their leaves. It is the movement and evaporation of water from a plant’s leaves, stems, and flowers. Plants require water, but the roots only use a small portion of it for growth and metabolism. As a result of these processes, the remaining 97–99.5 percent is lost.
In the middle of a hot day, have you ever found yourself suddenly in the middle of a dense forest after passing through an open field or clearing? What do you do when the temperature drops by 20 degrees and you’re hit by a cool, moist air blast? In other words, this is what we mean when we talk about transpiration
Second – The Water Tank
We talk a lot about how the water tank helps keep the dome warm in the winter time.. It also helps to keep the dome cool throughout the Summer months. Depending on the dome’s size, the water tank can hold 600 to 3,000 gallons of chilled water. This water is used to cool the dome’s interior. In a greenhouse where the temperature is 80 degrees, if you put your hand in the pond, it would feel much cooler than the air.
Metal framing allows for easy passage of heat between tank and surrounding environment. Even if it’s 90° outside and trying to go above 100°, the 75° water in the dome’s thermal mass keeps it cold. The top of the tank will also evaporate, contributing to the humidification and cooling of your dome. Solar Powered Waterfall’s new spray option helps to increase the amount of moisture in the air.
Install a tiny oscillating fan on the lumber brace behind the spitter to boost evaporative cooling from the water tank’s water vapors.
Third – Air Flow, Solar and Electric Fans
It is absolutely critical that a greenhouse’s air circulation and ventilation are optimized. Besides providing CO2 to the plants, a greenhouse’s ventilation system helps regulate temperature and humidity. It is common for greenhouses to be enclosed constructions that are unable to breathe themselves. Grown Spaces has created automated vents and fans to offer easy and reliable ventilation.
Here’s an illustration of how a 110-volt fan moves air in our 33-foot Growing Dome. We also employ solar-powered direct drive cooling fans.
With every Growing Dome greenhouse system, you can add an extra solar-powered exhaust fan. Fans, shutters, a uni-vent piston, and a solar panel are included in the package, as well as the hardware needed for installation.
There is now a standard solar attic fan in both the 33′ and 42′ Growing Domes. The 26′ model can also be upgraded to have this feature. In order to keep the Growing dome cold, the larger domes require more vigorous circulation. Existing domes can easily be upgraded with this new feature.
Fourth – Automatic Vent Openers
The upper and lower vents can be seen in this picture.
Our heat-activated, battery-free automatic solar greenhouse vents keep your greenhouse at a comfortable temperature all year round. The expansion and contraction of a beeswax solution within a cylinder and piston causes the top and lower automatic greenhouse vents to open and close at a predetermined but adjustable temperature. Thereafter, warm air exiting from the top vents of the Growing Dome® greenhouse is replaced by cold air being pulled in through the lower vents. The “chimney” effect is caused by heating the growing medium. Solar greenhouse vent openers can be disengaged during the colder months so that the vents can be closed at will.
Heat is removed from the top of the dome and replenished with cooler air from the bottom vents, creating a natural convection system in the growing chamber.
Fifth – Creating Shade
In your Growing Dome, there are two primary methods for generating shade. The first method is to look for plants with huge leaves in nature. As a result of the huge leaves shading the soil, your greenhouse stays cooler. (The more transpiration there is, the more widespread the leaves are.) In the summer, deciduous trees on the South-West side of your dome are an excellent method to keep your dome cool.
Our custom-designed aluminet shade cloths provide a second option for creating shade. Without depriving plants of too much light the shade cloth reduces the quantity of summer sunlight by 50% without harming them. They are included as part of the kit and are specifically designed to accommodate the various Growing Dome sizes. The package includes strings and eye bolts for fastening it to the greenhouse struts. Most Growing Dome owners erect their structures in the spring and remove them in the fall, usually between the months of April and June.
Dark-colored shade fabric will get hot and even raise the temperature if used, though.
Aluminet® is the brand name for this shade fabric. Despite the fact that it is constructed of aluminum, it does not heat the Growing Dome.
A 50% shaded area is ideal.
Do not completely envelop the dome in fabric. There is a fine line between too much shade and lanky plants.
Using a south-facing shade cloth reduces midday sun while still allowing for morning and evening rays.
Sixth – Undersoil Fan/Climate Control System
Perforated 4′′ pipes are buried in the raised beds around the perimeter of the greenhouse to take advantage of the soil’s natural geothermal capacity. Undersoil ventilation, often known as the central air system or undersoil heating and cooling system, is what we’re talking about. For this reason, the pipes’ ends protrude 3 – 6 inches over the foundation wall.
Those located on the south side of the greenhouse exhaust air into an overground pond. The 12 volts, 4 inch fan is mounted in a box that covers the exhaust pipes. The fan in the Growing Dome greenhouse is powered by a PV solar panel. The fan moves the warm or cool air around the pond through the pipes and soil at a rate of 70 cubic feet per minute (CFM).
When it’s cold outside, this helps to keep soil at a more comfortable temperature. In addition, the fan helps to move and circulate the air in the greenhouse.s.
With 75-degree dirt shadowed by 95-degree air blowing through it, we’ll be able to grow crops.
…the temperature of the air is 85°.
To cool the dome, we’re using pipes buried in the ground to blow hot air into them.
Seventh – Evaporative Cooling Systems
Up to 20° of cooling can be achieved by evaporating water and the power of moisture. In the dome, there are two ways to accomplish this.
One way is an evaporative cooler.
Known as a swamp cooler, evaporative coolers chill the air by allowing water to evaporate. The phase change from liquid water to water vapor can considerably lower the temperature of dry air (evaporation). This can significantly reduce the amount of energy required to cool the air compared to traditional methods like refrigeration or air conditioning. When used to cool buildings in dry climates, evaporative cooling adds moisture to the air, making it more comfortable for the people within.
The evaporative coolers manufactured by Southwest Solar are ideal for solar-powered applications. We have an 18′′ swamp cooler in our 26′ dome, and we recently placed a 24′′ in a customer’s 33′ dome in Las Animas, COdome .’s A window-mounted device, such as the one pictured above, is ideal for 110V versions. Similar to our fan units, these have a narrower aperture and will be mounted through the glass. It’s customary for us to follow a recommendation based on square footage from the product’s maker. If installed to the west for late-day cooling, they are more efficient.
Swamp coolers, if you live in a humid area, will actually make the air more humid. If you live in a humid area, an air conditioner is the ideal choice. Mold can thrive in a damp environment, causing a wide range of health issues.
In this video, Udgar demonstrates how to use our swamp cooler’s solar panel-powered features. It’s a great way to keep the dome cool while it’s running—up to 20 degrees cooler. Water trickles down or is sucked up a pad in the swamp cooler, which keeps the air moist.
Air can flow freely through the cooling pad.
This swamp cooler’s fan is powered by a solar panel. Outside, a small pump circulates water through a cooling pad, resulting in air that’s around 70 degrees.
The second way we use the power of evaporating water is a Misting System.
Misting systems can be programmed to operate on a variety of timings and humidistats. In order to prevent mold or fungus from growing, use a fine mist of water to mist the area before turning on the air conditioner. A garden hose or drip irrigation system can easily be connected to our misting system included in the Desert Cooling Package. Evaporative cooling principles are employed by the full-surround misting system to keep your greenhouse at a comfortable temperature.
It’s possible to grow food in your greenhouse, or in a Growing Dome…
I’m sure it will be hot in there as well.
Learn how to keep track of the temperature in a precise manner. Do not place your thermometer in full sunlight or under a dark pot!
Learn how to “hear” your plants’ messages. They’ll let you know if it’s getting too hot in there.
Cooling down the Greenhouse
Make sure your greenhouse has a ventilation system before you look into any of the other cooling alternatives I listed.
A ventilation system in a greenhouse is a given if you’ve even skimmed through a single greenhouse article. There’s no joking around here. Your greenhouse will become a hot, steamy, and humid mess if you don’t have a ventilation system. A ventilation system will also kill your plants because it gives them with the carbon dioxide they require to grow.
When you install a ventilation system in your greenhouse, heated air is expelled from the roof and cool air is introduced through an opening in the floor. Natural and mechanical ventilation methods are available. An overview of the fundamentals of each is provided below.
The remaining choices are as follows. It all depends on where you live and what you’re growing when it comes to the quantity of cooling you’ll need. My recommendation is to start with the cooling alternatives that may necessitate some initial effort, but can then be left in place and continue working for years to come.
Plant deciduous trees
A good place to begin cooling your greenhouse is by planting deciduous trees. The leaves of deciduous trees fall off in the fall.
Because of this, your greenhouse will have plenty of natural shade during the hotter months of spring and summer. In the fall, when the trees drop their leaves, you’ll have a clear route for the sun to shine into your greenhouse.
Look for an area where deciduous trees have already grown or one where you can plant some if you haven’t yet installed your greenhouse. All deciduous trees, including oaks, maples, ash, poplar, and beech, are examples.
If you already have a greenhouse, you’re not out of luck. Plant some trees, and you’ll reap the benefits in the long run; in the meantime, you’ll need to consider other cooling solutions.
It’s best to travel to a local nursery to begin, but you may also buy live tree seedlings online from Amazon. Here’s a medium seedling I stumbled across. See if it’s cheaper on Amazon
Place plants strategically
Your greenhouse may already contain plants with larger leaves if you’ve planned it carefully. Putting these in the appropriate area will assist reduce the greenhouse’s temperature and keep the soil cooler.
A natural evaporative cooler, large-leaved plants do more than just chill the earth. Because of their big leaves, they help to dissipate heat by evaporating water vapour.
Large-leaved plants like fig trees and grapevines are wonderful possibilities. They provide shade and a cooling effect through evaporation, but they also produce tasty fruit.
Shade cloth is a simple, inexpensive, and effective technique to shield your plants from the sun. The shade cloth can be draped over the greenhouse’s roof, pinned inside near the ceiling, or hung above your plants.
That’s a simple task. Shade cloth selection is the most difficult component of the process. It is available in a wide variety of materials and colors. Shade cloth is classified according to the percentage of light it blocks. From 5 to 90 percent density, this is known as density.
The amount of coverage your plants require determines the density you need. A look at the ideal density for different sorts of plants is provided here.
Shade fabric is available in a number of materials, but not all of them are created equal. Darker shades can actually raise the temperature since they absorb more heat. Aluminet is a good substance to experiment with. It is able to dissipate some of the heat because of its substance. Here’s one with a density rating of 50% on Amazon. See if it’s cheaper on Amazon
Install misters or a fogger
If you live in a dry environment, a mister or fogger might help keep your greenhouse cooler. Evaporative cooling is used by misters to keep your plants cool.
Tiny droplets of water are emitted from nozzles. Droplets are evaporated in the greenhouse using the greenhouse’s heat. Because heat is used, the temperature is lowered. In order to raise the humidity level in the greenhouse, misters are an excellent option. The ideal humidity level is between 50% and 70%.
Amazon has a misting system for less than $30. As the size of your greenhouse increases you may want to invest in more than one. See if it’s cheaper on Amazon
The water droplets in a fogger are slightly smaller than those in a mister. See if you can find it on Amazon. See if it’s cheaper on Amazon
You can also use a humidistat controller or a timer to turn on your mister or fogger based on the humidity level. Working smarter, not harder, should always be the goal.
Use an evaporative cooler
While misters and foggers use evaporation to chill air, an evaporative cooler goes even further. Evaporation of water due to atmospheric heat reduces temperatures by 10–20 degrees!
Overhead water and a gutter are used to collect water for the pad of an evaporative cooler. Pads are warmed by fans on the other side of the room. The greenhouse is kept at a comfortable temperature by the cool air passing through it.
Using an evaporative cooler in your greenhouse will save you money and energy.
For a smaller greenhouse, this one from Amazon would be a good option. on Amazon, you’ll find an evaporative humidifier
Portable Air Conditioner
Another alternative for cooling your greenhouse is a portable air conditioner. Air conditioners are the most expensive cooling alternative, which is a drawback.
Among the advantages of air conditioning systems is the fact that many include a dehumidifier. With the greenhouse cooling down, you’re also lowering the humidity level.
This air conditioner/dehumidifier combo is available on Amazon. Amazon has an air conditioner/dehumidifier.
Temperature Guidelines for Your Greenhouse
There are several ways you may cool your greenhouse, but you’ll need to know the ideal temperature.
80 degrees Fahrenheit is generally considered ideal in greenhouses, however the exact ideal temperature will vary depending on the plants you’re growing. Plants have a preference for either cooler or warmer temperatures. When it comes to keeping your greenhouse cool, it’s important to follow temperature recommendations.