evacuated tube collectors

Synonyms

evacuated solar tube collectors,

Definition

An Evacuated Tube Collector is a solar collector in which the absorber is contained in a sealed glass tube, thereby providing for relatively high temperature heat gain.

Most (if not all) vacuum tube collectors use heat pipes for their core instead of passing liquid directly through them. Evacuated heat pipe tubes (EHPT's) are composed of multiple evacuated glass tubes each containing an absorber plate fused to a heat pipe. The heat from the hot end of the heat pipes is transferred to the transfer fluid (water or an antifreeze mix—typically propylene glycol) of a domestic hot water or hydronic space heating system in a heat exchanger called a 'manifold'. The manifold is wrapped in insulation and covered by a sheet metal or plastic case to protect it from the elements.

These are rows of parallel glass tubes with black absorbent material on the back. Sunlight shines through the water and is absorbed into the black material to heat the water. Tubes are vacuum-sealed. This allows them to achieve much higher temperatures, making them appropriate for industry and commercial systems.

Most (if not all) vacuum tube collectors use heat pipes for their core instead of passing liquid directly through them. Evacuated heat pipe tubes (EHPT's) are composed of multiple evacuated glass tubes each containing an absorber plate fused to a heat pipe. The heat from the hot end of the heat pipes is transferred to the transfer fluid (water or an antifreeze mix?typically propylene glycol) of a domestic hot water or hydronic space heating system in a heat exchanger called a 'manifold'. The manifold is wrapped in insulation and covered by a sheet metal or plastic case to protect it from the elements.