Vacuum tube collector with flat reflector Vacuum tube collectors have higher efficiency in diffuse radiation (cloudy weather and winter), compared to flat plate collectors. The vacuum produced between the two glass tubes is a perfect insulating material which protects the collector from freezing when temperatures are even -18 °C. Our Calpak Vacuum VT are produced with 12 or 20 vacuum tubes of 1,5 m length. They are placed very close next to each other in order to minimize space. They can be exchanged separately. The flat corrugated reflector is made of granulated aluminium, which gives better results when dust or dirt are gathered on its surface, and snow can slip down easier.

Technical characteristics