Do-it-yourself automatic ventilation of the greenhouse: from two bottles or a fire extinguisher

Airing the greenhouse in sunny weather on those days when you are absent from the country, allow you to implement the following devices:

They will allow, depending on the air temperature, to open or close a door or window in the greenhouse. The principle of operation is approximately the same for everyone: the oil in the hydraulic cylinder expands or contracts depending on the temperature and pushes (or retracts) the rod, which opens (closes) the window or door.

Installation options for ventilators depending on their design.

But there are craftsmen who independently make something similar and no less effective with minimal costs, or even free of charge from scrap materials. First option:

You will need an old metal fire extinguisher (2-3 liters) and a used tailgate gas stop from any car. The gas stop will be given free of charge in any car service (they are often changed there). The gas stop must be tightly connected with a hose to a fire extinguisher. We fill the system with inexpensive oil or working off (after changing the oil in the car engine). This is the principle behind industrially manufactured oil pistons for automatic ventilation of greenhouses. Here we just repeat their principle.

The oil has a high coefficient of volumetric expansion. With a differential of 20 degrees, this is a significant value that can extend the stem. If the fire extinguisher is large, you can add pebbles or scrap metal to save oil.

A variant of a home-made automatic oil ventilator for greenhouses without hoses, installed for ventilation, opening the greenhouse door. Recoil spring for secure closing. But here you need welding - you need to scald the piston in the body of the fire extinguisher.

Polyethylene granules can be added to the oil. As a piston - use a bicycle pump filled with engine oil or waste. The thermal expansion coefficient of polyethylene is very high, higher than that of oil. Less oil will be needed.

The oil system has one drawback. She is quite inert. The oil needs to warm up for a long time to extend the stem. And the oil gives off heat for a long time. Those. with a sharp onset of frost, the window or door in the greenhouse will not close immediately.

Automatic ventilation system of the greenhouse based on shifting the polycarbonate sheet and opening several vents in the door or at the end of the greenhouse. Also based on an oil piston. This is the factory version. The cost of such a module is from 2500 rubles. But this design can be done with your own hands.

But the easiest way is to air the greenhouse out of two plastic bottles or a glass jar and a bottle:

The window in the greenhouse is like a lever. At one end of the arm is suspended an unsealed bottle, into which water flows from another (sealed) bottle or can (when pressure rises in it) through a thin hose (a dropper from a pharmacy). Communicating vessels based on gas expansion. When water is added to the bottle, the mass of the bottle increases - the window is lowered.

A prerequisite is that the large bottle must be lower than the one that is suspended from the arm.

One of the schemes. Here the second bottle is suspended from the second end of the window. This is not necessary if the axis of the window is not in the center, but higher.

A short video demonstrating a simple two-bottle system. Only copper sulfate or a little bleach for clothes should be added to the water (so that the water does not bloom).

***

Photos are taken from open sources, from Yandex. Pictures

Subscribe to the channel, add it to the browser bookmarks (Ctrl + D). There is a lot of interesting information ahead.