As you can tell guys I am on my way to prepare my greenhouse for the summer time.
I’ve started with the spring clean and now I am thinking of the best ways to cool my greenhouse on the hot summer days.
It might be a little bit too early to think about it but I like to plan everything ahead.
Well, I try and fail (sometimes) and then I am trying again 😀
OK, in this post I want to talk about the easy-peasy methods which can keep our greenhouse cool.
Also, I am going to answer the most popular question when it comes to cooling: ‘How to cool a greenhouse without electricity?’
How do you cool down a greenhouse?
Don’t rush into nearby gardening store to buy some overpriced electric fan just because you saw the weather forecast for the new week.
Think of what you can do to keep your greenhouse cool without spending any cash. You might need to invest into a couple of things if you already don’t own them.
So, the first essential step you have to follow is to provide your greenhouse with a good ventilation.
How to cool a greenhouse without electricity?
Tip #1 – Ventilate your greenhouse
In simple words ventilation is a flow of air inside the greenhouse which you can create by opening roof vents, side vents and doors.
If you have manual vent openers, I would suggest to have a wireless thermometer.
It monitors temperature changes and sends data directly to your phone or a computer. That way you will be aware whether you need to open the vents.
On the other hand, you can use automatic vents which have wax cylinders in their structure.
These expand or shrink according to the rise or fall of the temperature. Now, you might want to know how many vents you need inside your greenhouse.
Well, ideally, to calculate the number of vents you need is equivalent to the one fifth (20%) of the floor area. This will provide your greenhouse with an air circulation every 2 minutes.
To maximize the advantage of ventilation you have to maintain a good air movement inside your greenhouse.
What is it and how to do it? As you might know cool air is located at the bottom then it warms and rises.
Therefore, setting up louvered vents at the lower walls of you greenhouse allows cool air to enter the greenhouse from the outside.
At the same time air warms and rises escaping through the roof vents. Master ventilation in your greenhouse and then move onto shading.
Tip #2 – Shade your greenhouse
Shading is a second very accessible, very easy and very cost effective way of cooling a greenhouse.
There are a few types of shading which you can use: shade paint, blinds and shade cloth.
The main work principal of all types is in lowering inside temperature by eliminating the passing sunlight.
Let’s start with the shade paint.
Shade paint – this is typically mixed with water and applied with a brush to an external side of the greenhouse glazing.
Some of the newest paints are reacting to sunlight and turning white to reflect the sun rays back.
Also, these are water resistant, so when it is raining paint becomes transparent and turns white again once it dries out.
However, you can’t use it on any greenhouse. For example, if your greenhouse is made of natural wood or is glazed with acrylic or polycarbonate you might need to stay away from the shading paint and optimize for the blinds or shade cloth.
Greenhouse Shading Blinds
Shading blinds is probably the most expensive shading option and comes in two types: external and internal.
External blinds are fit to the outside of the greenhouse and provide the maximum cooling effect.
When the weather is cloudy, you have to lift them up to let the light in. It can also be done automatically but obviously tends to be more pricey.
In comparison to the external blinds, internal blinds are set up on the inside of the greenhouse and are much easier to install.
However, these are loosing in the cooling effect because sun rays are passing through the glazing and warm the temperature inside the greenhouse.
Greenhouse Shade cloth
I have talked a lot about the shade cloth in my previous article, so you can find more information there.
I just want to say that this is probably my favorite shading option. It is easy to install, you don’t need to re-apply it in comparison to the shading paint.
Also, it is not as expensive as shading blinds and you can easily adjust it to the size of your greenhouse.
So, you became an expert in greenhouse ventilation and know how to use an advantage of the shading.
Now it’s time to think about the atmospheric humidity. In other words, we are going to talk about damping down.
Tip #3 – Damping down a greenhouse
Humidity can seriously affect the heating inside your greenhouse on a bright sunny day.
What is damping down?
The easiest way to increase the moisture levels in the air is damping down. What is it?
That’s a process of wetting hard surfaces like paths and staging inside your greenhouse throughout the day.
On average, you have to damp down three times a day – in the morning, during the lunchtime and in the evening.
How does it work? The principal is very easy. The water evaporates from the hard surfaces and raises the humidity inside the greenhouse.
It is always beneficial in pests control as many of them thrive in the dry air conditions.
Tip #4 – water the plants in a greenhouse
It is very important to water your flower and plants during the hot summer days. Don’t forget that plants can keep themselves cool through a process known as transpiration.
The plant is loosing moisture through the pores which are found in leaves. This lost water cools down the surface of the leaf. Think of it as it was sweating.
Transpiration is faster when temperature rises. Therefore, plants are going to use more water.
The source of water for transpiration comes from soil. So, you have to water your plants more often when it’s hot to avoid overheating and becoming wilt.
These are four fundamental ways of keeping your greenhouse cool. Sometimes it might not be enough depending on several factors.
For example, geographical location, levels of humidity or orientation of the greenhouse. In this case you might want to consider investing into more complicated cooling systems.
I hope you found this article interesting as well as useful. Please let me know your go-to tips on how to cool a greenhouse and what does work for you.
Have a nice day everyone 🙂
