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Best automatic greenhouse vent openers for controlling the temperature and increasing airflow in your greenhouse

Looking for the Best automatic greenhouse vent opener? Check out our guide below and you’ll be well-placed to select the correct one for your needs.

Do you rush out to your greenhouse in your pyjamas when the sun comes up in the morning to open the window so the plants don’t overheat in the hot air?
Are your neighbours hesitant to open and close your greenhouse door as the temperature changes while you’re away?
Automatic vent openers are definitely worth installing because they take the stress and human time and work out of ventilation your greenhouse.
Automatic vent openers are attached to a window (typically in the roof) and open when the greenhouse is hot and close when the weather cools.

In any weather, good greenhouse ventilation is essential to keep your plants from being too overheated.
You can always monitor the temperature and go in and out to open the window vents as needed by your plants.
But will you remember to do so throughout the entire spring, summer, and autumn?

Greenhouse automatic vent openers (also known as autovents) take the guesswork out of providing proper ventilation and maintaining a comfortable temperature for your plants.
Automatic vent openers open the vent/window at a predetermined temperature and close it when the temperature drops.

Autovents are similar to one other, according to the individual reviews in this article.
It’s possible that the minor alterations will go unnoticed at first.
This Buyer’s Guide explains what to look for in an automated window opener so you can pick the finest model for your greenhouse.

How does a vent window opener function automatically?

Mechanical, solar-powered, or electric window openers are available.
All of the vent openers discussed in this article are mechanical, so we’ll concentrate on that.
Electric window openers, unlike mechanical ones, require a power source to operate the powerful electric mower that opens the windows.
An external temperature gauge is also required by electric vent openers in order to determine whether the temperature hits the pre-set limit or changes.
Vent openers of this type are typically found in large commercial greenhouses.

Mechanical automatic openers, on the other hand, work in a simple yet innovative manner.
They operate using a metal cylinder containing mineral oil, which expands when heated.
The expanding wax forces a piston to open the auto vent and window.
When the temperature in the greenhouse drops and the wax cools, a spring compresses, closing the window and resetting the piston.

There is no requirement for a power source or an external temperature sensor with these mechanical vent openers.
The wax is heated or cooled by the sun, and the opener performs its function.
The temperature at which the window is opened is normally adjusted by rotating the adjustment knob on the end of the unit.


Metal is commonly used for automatic vent openers.
They gain strength and resilience as a result of this.
Rust-resistant units include those that are powder-coated, aluminum-coated, or anodized.
Check for galvanised coating on all fastenings and fittings so you may securely leave the vent opening out in the winter.
The galvanised metal also protects them from rusting in the greenhouse due to dampness.

Examine the oil cylinder, piston, and spring as well.
There should be no snags or scrapes as they work together.
Over time, the cylinder deteriorates and loses its temperature sensitivity.
When this happens, you must replace the cylinder.
Some manufacturers sell the cylinder separately, while others need you to purchase an additional unit.
Automatic window openers with interchangeable cylinders are perfect and much more environmentally friendly if you’re on a budget or simply don’t want to pay more than you need to.

Selecting the Best Greenhouse Window Opener for Your Vent Size

The size of the window that can be opened and closed is connected to the lifting capacity (also known as load capacity).
In general, the heavier a window is, the larger it is.
However, if the glazing is made of polycarbonate or other polymers, your large windows may be lightweight.
Measure the window’s dimensions and weight to ensure you’re selecting an automated vent opener that can open your vent.

Many of the vent openers in this study claim to be able to open windows up to 60cm x 60cm, which is common for most greenhouses.
The openers in this review can move vents weighing between 5.5 and 7 kilogrammes.
If your greenhouse windows vents are particularly large or heavy, search for an opener that can manage weights of more than 7kg.

Range of temperatures

Automatic vent openers are designed to keep your plants at the optimal temperature for them.
Most openers feature a temperature range from which you can select the desired opening temperature.
The window opens when the greenhouse achieves that temperature.
The window’s maximum opening is normally upwards from a fixed temperature.
For example, the temperature range for opening the window could be 15°C to 25°C, with a maximum opening of 30°C.

Some vent openers have a larger opening range and a higher full extension maximum.
Make sure to purchase a vent opener with a temperature range that suits your climate and the plants you grow.

Best automatic greenhouse vent openers to buy

SaleBestseller No. 1
Bayliss XL Auto Vent Opener
  • 2 year manufacturer
SaleBestseller No. 2
Speedwellstar Greenhouse 15KG Window Vent Opener 2 Spring Automatic up to 15 kg load Solar Auto Heat Sensitive Kit Twin Double Springs Heavy Duty New uprated piston
  • This opener will automatically open and close your greenhouse window to control the temperature inside
  • 2 Springs making this very strong * Suitable for most greenhouses * Uses solar energy - it's FREE to run!
  • Temperature changes in your greenhouse will trigger the opening device, the working conditions are - * Start to open - 15°c - 23°c (59f-73f) * Fully open temperature 35° (19f) or above * Fully open distance 45cm (18") * Maximum opening weight 15 kg
  • Can be fixed onto aluminium frames, or screwed into the frame * Fitting instructions included * Simple to fit * Can be adjusted to different temperatures
  • Screws for fittings included (Please ensure all are tight on fitting)* Things to remember - Please ensure your greenhouse window can be opened freely by at least 45 cm (18") We carry replacement parts for most of the items so please contact us if any problems.
Bestseller No. 3
upstartech Greenhouse Window Openers Automatic Vent Opener with Double Spring, Up to 15KG (WOP2)
  • High-quality Materials: The window opener is made of high-quality aluminum, which is durable and rust-proof in humid environments and has a long service life. The aluminum cylinder body is sprayed with paint and has strong weather resistance.
  • Double Spring: The double spring mechanism provides stability and flexibility, and can withstand high winds. Suitable for most greenhouse windows, the maximum weight of the ventilation window is less than 15kg, so you can use it with confidence.
  • Automatic Window Opener: The vent opener automatic can automatically open and close the greenhouse windows to control the greenhouse temperature when the temperature changes. It do not consume energy, batteries or power. The maximum opening distance is 45 cm.
  • Temperature Adjustable : Due to the thermal induction of the temperature, the window opener will automatically open and close. Maintain the optimal growth temperature and prevent the greenhouse from overheating. 15℃-25℃. When the temperature exceeds 25°C, the window opener will remain open. When the temperature drops to 15°C, the corkscrew will be completely closed.
  • Easy to Install: Equipped with screws, you can use a screwdriver to screw directly into the panel, wood or metal frame, very simple and convenient, if necessary, you need to use a drilling tool to screw it into the channel and fix it. Attached an installation manual, if you have any questions, please feel free to contact us.
SaleBestseller No. 4
Leafy Creations. Black Greenhouse Window Opener Automatic, Solar Powered, Universal Vent Openers, Wooden or Alluminium Greenhouses Accessories.
  • ✅ Universal. These Black greenhouse automatic window opener with a Double Spring is compatible with ALL major Greenhouse window openers designs and can be clamped or screwed to Aluminium or Wooden frames.
  • ✅ Solar powered. The greenhouse vent opener uses the heat in your Greenhouse to auto operate, power free, no cables or batteries,
  • ✅ Reliable Spares Parts Available. The only universal automatic greenhouse window opener supplied FREE of charge with the tried and tested ultra reliable Leafy Creations Power Cylinder. Also available as a spare part accessory.
  • ✅ Optimal Growth Temperature. Plant germination equipment needs to function correctly, our greenhouse vent opener automatic opens at 16° (60°F) to maximum 26° (79°F), helping to maintain a perfect growing environment.
  • ✅ Branded Support - Any problems, we are always here in the UK to help, providing direct responsive assistance and support all year round.
Bestseller No. 5
Decdeal Greenhouse Windows Opener, Temperature Controlled Automatic Vent Opener with Single Spring
  • STRONG MATERIAL:Aluminum frame looks more lustrous, durable and rust-proof and stainless steel accessories would last long time use.elongated aluminum cylinder with paint spraying, weather resistant.
  • AUTOMATIC VENT OPENER: Solar heat sensitive vent opener, automatic stretch or shrink the vent while the temperature is changing.Maximum opening distance: 45 cm / 18 inches.
  • ADJUSTABLE TEMPERATURE:Auto-opening temperature range is adjustable, when the temperature is lower than 15-25°C (60-77°F), the window will automatically close. When the temperature reaches 30°C, the window will open automatically.
  • EASY TO INSTALL:universal fit for all aluminum frame greenhouse.suitable for the vents weighting up to 7kg/15lb.
SaleBestseller No. 6
Elloughton Greenhouses The Original Ellovent™ Automatic Greenhouse Window Opener, Adjustable Roof Vent Autovent, Solar Powered
  • The Original Ellovent Greenhouse Vent Opener
  • Solar Powered Autovent - Proudly made in Denmark for us
  • Opens and Closes Greenhouse Window Automatically
  • Easy to Install and Adjust Opening Temperature
  • These High Quality Window Openers are Guaranteed for Two Years
SaleBestseller No. 7
Kavolet Greenhouse Window Opener Automatic, Solar Heat Sensitive Vent Opener with Single Spring, Agriculture Gardening Greenhouse Acessories, Temperature Controlled Auto Vent Opener Lifts
  • Elongated aluminum cylinder with paint spraying, weather. Resistant.Stainless steel accessories would last long time use.
  • Solar heat sensitive vent opener, automatic stretch or shrink the vent while the temperature is changing.
  • Aluminum frame looks more lustrous, durable and rust-proof. Easy to install, universal fit for all aluminum frame greenhouse.
  • Auto-opening temperature range is adjustable from 15-25℃(60-77℉). Maximum opening at about 30℃/86℉(depending on adjustment and load).
  • Greenhouse window opener is suitable for the vents weighting up to 7kg/15lb.
Bestseller No. 8
Leafy Creations Replacement Cylinder for Bayliss XL Greenhouse Window Opener, Autovent, Automatic Vent, Solar Heat Powered. Auto Ventilation Power Tube.
  • ✅ Save Money, replacement cylinder only----If your Bayliss XL openers have stopped opening or dont fully open, it is simply the cylinder that needs replacing. Why waste money buying a complete autovent, when you can easily and for much less money simply replace the cylinder.
  • ✅ COMPATIBLE---This replacement power tube fits ONLY the Bayliss XL greenhouse window opener. Will not fit other Bayliss openers. Please compare with the dimensions image to see if this cylinder is compatible with yours.
  • ✅ EASY INSTALLATION---Please read below in 'Product Description' for a simple DIY installation guide.
  • ✅ PERFECT GROWING TEMPERATURE---Opening Temp. range 16°C-26°C (60°F-78°F) helping to maintain optimal growing conditions in your greenhouse.
  • ✅ PLEASE NOTE: There is no need to cool in the refrigerator or freezer, Please refer to the instructions below.
Bestseller No. 9
Automatic Greenhouse Vent Opener
  • Opens and closes standard greenhouse windows automatically
  • Simple to fit, needs only basic DIY skills
  • Fully adjustable to start opening over a wider temperature range than the cheaper models
  • UK manufacturer with over 50 years experience of manufacturing quality autovents
  • Protects your plants automatically from the worst heat damage that can occur in an unventilated greenhouse
SaleBestseller No. 10
Leafy Creations Replacement Cylinder for Greenhouse Window Opener Automatic. Temperature Controlled Power Tube for Automatic Window Opener. Auto Vent Greenhouse Accessories.
  • ✅ Replacement Cylinder Only. Save money with greenhouse window openers accessories. If your greenhouses window has stopped opening, it is simply the cylinder that needs replacing on your automatic greenhouse vent opener automatic. Why waste money buying expensive greenhouse parts you dont need, when you can simply replace the cylinder.
  • ✅ Compatible Fittings. Compare our spares with your existing greenhouse window opener, if it looks the same, it is the same!!! Suitable replacement greenhouse automatic window opener cylinder for Orbesen, Halls, Palram, Grozone, Gardman, B&Q and most other UK and foreign branded windows vent openers.
  • ✅ Easy Installation. Our greenhouse automatic vent opener cylinder is a simple DIY installation and suitable for single or double sprung vents. Also a suitable replacement for most greenhouse louvre vent opener.
  • ✅ Perfect growing temperature for any plant. Your automatic greenhouse window opener temp sensor range 16°C-26°C (60°F-78°F) helping to maintain optimal growing conditions in your growing environment.
  • ✅ Instructions. Please see 'Product Description' below for a guide to fitting our greenhouse spares vent opener automatic and see images for a dimension diagram.

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