How Do Solar Vacuum Tubes Work

As the area of one tube is small to increase the heat collection area a number of tubes are connected to one manifold although just one tube is shown in fig.

How do solar vacuum tubes work.

The outer layer of the solar tube is borosilicate glass which is very low in iron and allows 98 of light energy to pass through. A vacuum is needed to keep the electrodes from burning or oxidizing the same reason a vacuum is needed in a light bulb a light bulb is actually a single electrode tube. The principle behind solar vacuum tubes is simple. Evacuated tube collectors are made up of a single or multiple rows of parallel transparent glass tubes supported on a frame.

These usually consist of a heat pipe inside a vacuum sealed glass tube. So how do solar vacuum tube collectors work. A vacuum tube an electron tube valve british usage or tube north america is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The vacuum tube is made of borosilicate glass which is very low in iron and as such lets through more solar radiation than ordinary glass it is also very strong.

Each individual tube varies in diameter from between 1 25mm to 3 75mm and between 5 1500mm to 8 2400mm in length depending upon the manufacturer. How do they work. A solar tube commonly referred to as a sun tunnel is a skylight alternative for channeling sunlight to a building s interior. The vacuum also keeps the electrons in the tube from colliding with air molecules which would generate noise.

Evacuated tube solar collectors operate in a different way from the collectors presented so far. A solar vacuum tube works similar in design to a coffee thermos. It consists of a two layers of glass with a vacuum in between the layers. The type known as a thermionic tube or thermionic valve uses the phenomenon of thermionic emission of electrons from a hot cathode and is used for a number of fundamental.