Draft PPS18: Renewable Energy
Annex 1 Technology: Evacuated Tube Collectors
G7. Evacuated tube collectors comprise a number of vacuum tubes, typically around 100mm in diameter, and 2 metres in length containing a finned metal collector tube. Each tube is filled with a heat transfer fluid, and the upper ends of individual tubes are connected to a manifold heat exchanger, which is connected to the hot water system of the building as in the case of flat plate collectors. Evacuated tube collectors do not require protection against frost.
G8. Although both types of collector will collect more energy during summer months, a significant amount of energy will also be collected on cold winter days, and evacuated tube collectors are more effective in doing this.