Solar Pool Heating Evacuated Heat Pipe Solar Collectors (tubes) operate differently than the other collectors available on the market. These solar collectors consist of a heat pipe inside a vacuum sealed tube. Solar energy is concentrated on the top of each tube and diverted through a manifold to a storage tank or load. This new Photo Thermal Conversion technology absorbs solar radiation and converts it into heat (photo-thermal conversion). The high efficiency solar collector implies maximum absorption of incident solar radiation with a minimum thermal and optical loss. Selective coating characteristics of the absorber and the vacuum insulation are the most important parts of an advanced collector. A selective surface has high absorption (low reflection) for the solar spectrum and low emissivity for the infrared heat radiation. The selective coating used in the collector consists of a thin, precise layer of an amorphous semiconductor plated on to a metal substratum; this has a low emission for long-wave radiation. Sounds pretty complicated but it is actually quite simple. Just a very efficient way to squeeze as much solar heating energy, without a high ambient temperature needed to capture heat. They are also strong enough to carry the weight of an average person and the impact of golf size hail storms.