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Lacewing™ Essential Automatic Vent Arm Window Opener / Autovent

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Lacewing™ Essential Automatic Vent Arm Window Opener / Autovent

The autovent window opener is an all-in-one solution for greenhouse temperature control. Using a cleverly designed pressure system, the arm opens the window if the greenhouse is over a preset temperature, and closes the window below this temperature. Care for your greenhouse plants, even when you're not at home.

All greenhouses need to be well ventilated on hot and sunny days to keep plants in optimum growing conditions. The automatic vent arm uses captured gas which expands in hot temperatures, opening the window without any running costs. The simple but smart mechanism will maintain optimal temperatures at all times, whether you are or aren't at home. You can adjust the opening temperature between 15° and 20°C to suit your individual needs. Simply install the vent opener by using the instructions and let it do its job.


  • Automatically opens and closes window at preset temperature - increases air flow and relieves your plants in hot temperatures
  • Fully adjustable to open between 15°-20°C - set the temperature the window will open and close at to care for your specific plants and climate
  • Opens up to 35cm wide - opens wide to encourage air circulation
  • Mechanical system activated by heat - no electricity needed, which means no running costs
  • Perfect for windows that weigh up to 7kg - opens nearly all greenhouse windows
  • Chrome coated metal - increased corrosion resistance
  • Length: 32cm (1ft ½in) x Depth: 5cm (1¾in) x Height: 4cm (1½in)
  • Max. opening width: 35cm (1ft 5⅔in)

Primrose is the place to be to Discover Everything Garden.

We were created in 2003 to become the UK's largest online-only garden centre. Thousands of plants, planters, awnings, garden furniture sets, water features and more line our digital shelves, and we're ready to fill your garden with comfort, quality, colour and style.

If you'd like to find out more, check out our 'About Us' page.

We want you to be happy with your purchase from the moment it arrives, but if you aren't you have the right to return it within 14 days. Just head to our Returns Page, send us an email, receive a returns number and fire your product back to us.

We'll refund the full cost as well as standard delivery.

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We calculate delivery costs at checkout based on your entered postcode, so you'll know at that stage if your chosen product can be sent to you. If you have any queries, please head to Contact Us and send over a form, or visit our Help Centre.

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Installing a Vent Arm

Style Accessories
Sale Category Greenhouses
Spring Checklist Greenhouses
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