An open vent in a greenhouse

How to fit an automatic greenhouse vent opener

Find out how to fit an automatic greenhouse vent opener with the help of our practical step-by-step guide.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
To do
To do

Do not To do in January

Do not To do in February

Do not To do in March

Do not To do in April

Do not To do in May

Do To do in June

Do To do in July

Do To do in August

Do not To do in September

Do not To do in October

Do not To do in November

Do not To do in December

Keeping your greenhouse cool in summer is essential, as high temperatures can cause heat stress, damaging your plants and potentially, your crops.

Damping down and providing shading in the form of blinds, screens and shading paint can help, and it’s really important to encourage good air circulation by opening the doors and vents.

You can make sure your greenhouse ventilation is constantly regulated during hot summer months, whether you’re at home or not, by installing an automatic vent opener. It contains a wax that expands when heated, opening the vent. When the temperature falls, the wax contracts and the vent closes.

UPVC greenhouses have lightweight roof vents and may require a stronger vent opener to keep them closed or prevent them being blown away – check before you buy.

Available at garden centres or online, automatic vent openers are quick and easy to install – here’s how to do it.


You Will Need

  • Greenhouse
  • Automatic ventilation kit
  • Screwdriver
  • Screws

Total time:

Step 1

Place the opener in the centre of a window vent and mark the position of the holes on the window frame and greenhouse frame.


Step 2

Screw the automatic window opener to the frame of the window then check that the window can open and close.


Step 3

If necessary, adjust the amount the window opens by rotating the main tube of the vent opener.


Step 4

On a sunny day, watch and wait to see that the vent is opening properly.


Essential greenhouse kit

Find out about more useful items for your greenhouse in our guide to essential kit for your greenhouse