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Optivent Opener Used In Greenhouses


Did You Know? When a window you are trying to open with a optivent solar vent opener weighs 33 pounds, the weight (15 lbs) rests onto the opener and the other (15 lbs) onto the hinges.

i.e. A vent window is usually hung with aolar opener and a pair of top hinges.

Therefore, (7 Kg is not exactly = 15 lbs   but = 16 lbs.  And 2 x 16 lbs = appr. 33 lbs).
The exactly measure is 7.5 Kg x 2.2 = 16.5 lbs x 2 for hinges+opener = total 33 lbs.

Not everyone is aware of the difference in weight on the opener compared to the weight of the vent. This is the reason why the lifting rate is shown as 15 lbs., when the oppener can actually raise a 33 pound window when the window itself is attached to a frame by hinges. 

SO : the 33 lbs is the correct figure








1. Your automatic window opener is not suitable for use where temperatures will exceed 50C/122F.
2. Ensure that your greenhouse window is able to open and is not obstructed otherwise damage could occur.

Approximate arm length is 11 inches.

Technical data:
A. Maximum window opening approximately
45 cm/18".
B. Maximum opening at 30C/86F depen
ding on adjustment and load.
C. Suitable for greenhouse vents weighing up to
7 kg/15 lb.
D. Your window opener can be adjusted to
open at temperatures in the range 15'-25C/

See fig. 1.
1. Cylinder
2. Cylinder housing
3. Arm B
4. Arm A
5. Push rods
6. Frame bracket
7. Window bracket 8. Clamps

Lubricate all movable parts with a light oil after fitting, each spring and as required during the summer. Apply petroleum jelly to the cylinder thread occasionally.

Winter storage:
It is recommended that your window opener - or at least the cylinder - is removed from your greenhouse for the winter. Store it in a dry place and do not forget to lubricate particularly the piston rod before remounting in the spring. Check that the piston rod moves smoothly.


Your automatic vent control is guaranteed for one year provided that it has been fitted and maintained in accordance with the instructions.

Fitting instructions:

1. Check that the greenhouse window opens freely and is not obstructed.
Remove existing casement stays and arms from the window and frame.
2. Loosely fit a clamp (8) to the window bracket (7) using two of the screws supplied, see fig. 2. On wooden greenhouses the brackets can be screwed directly on to the woodwork, see fig. 3.
3. Choose the most suitable pair of holes and loosely fit the other clamp to the frame bracket (6). Ensure that the upper edge of the frame bracket is as close to the edge of the window frame as possible. See examples in fig. 3.
4. Now measure the distance that your window will open.
A. If the window will open at least 42 cm/ 16'/z ":
Fit the opener as delivered to you.
B. If the window will only open between 30 and 42 cm/12" and 16": Unscrew the screw keeping the push rods (5) and the arms (4) together. Move the assembly with the arms from hole A to hole B in the push rods as shown in fig. 4. Screw in the screw again.
5. Fit the frame bracket in the middle of the window sill, see fig. 5.
6. Fit the window bracket to the window frame just above the frame bracket. The window must be in the closed position.
7. Open the window sufficiently to allow you to screw the cylinder into the cylinder housing. Screw in the cylinder until the thread is equal length on both sides of the housing and release the window.


It is recommended that the vent control is adjusted when the temperature in the greenhouse is constant as it will take some time before it has responded completely to changes in temperature. In order that your window opener should start opening the window at a different temperature, adjustment can be made by turning the cylinder:
Clockwise to achieve an earlier/higher opening.
Anticlockwise to achieve a later/lower opening.
One complete turn corresponds to app. 0,5'C/IF. -You should note that the temperature in your greenhouse may vary considerably, also at the individual windows.

Our customer service staff can assist you in selecting the proper accessories for your unique needs.