TECHNICAL MANUAL VACUUM TUBE SOLAR COLLECTORS Solar Keymark OFFICIAL QUALITY MARK OF THE EUROPEAN UNION

DESCRIPTION Calpak VTS is a vacuum tube solar collector, consisting of twin wall glass tubes and an air vacuum between their walls of 5.10-3 Pa. These tubes are manufactured from borosilicate glass. The outer tube has a diameter d=47mm and is 1.8mm thick. Respectively, the inner tube has a diameter d=33mm and is 1.5mm thick. The inner tube surface towards the vacuum is specially treated to allow selective behavior. Each of these tubes contains a U-shaped copper tube with Φ3/8'' diameter. This is fitted with copper fins to improve heat transmission properties. Each tube is connected to a heat...

ANTIFREEZE PROTECTION OF COLLECTORS In order to ensure the anti-freeze and anti-corrosion protection of the collector, we offer the Calpak thermal fluid , which is a propylene glycol based product (provided as an accessory). This thermal fluid is mixed with water, at a minimum volume ratio of 20%. In areas with low winter temperatures, this ratio changes, as shown in the table below: Thanks to the excellent heat insulation provided by the vacuum and their selective surface, Calpak VTS collectors are highly efficient in cold winter climates, where temperatures drop below zero centigrade. They...

Drawing of the Calpak VTS Collector FRONT & SIDE VIEW 1. Header aluminum cover 2. Glass wool thermal Insulation 3. Expanded polyurethane thermal insulation 4. Header copper tubes, Φ18 (Φ22) 5. Recess securing the collector 6. O-rings made from EPDM or equivalent 7. Glass vacuum tubes COLLECTOR SECTIONAL VIEW, AB 8. U shaped copper tube 9. Aluminum reflector 10. Aluminum base with mounting recess 11. Plastic caps with UV protection supporting the vacuum tubes SECTIONAL VIEW OF TUBE SECTIONAL VIEW CD, DETAIL 1. Vacuum tube 2. Parabolic Aluminum Reflector 1. Outer Glass Tube 2. Inner glass tube...

TECHNICAL CHARACTERISTICS * Only on special order and in significant quantities

Q = Effective output power of the collector (w) G = Total solar radiation intensity (w/m2) A= Collector absorber area (m2) n = Collector thermal output (%) U = Total coefficient of collector losses (w/m2k) based on the window surface (Solar KeyMark)

Note: The pressure drop curves of intermediate models are between the two extreme curves and can be determined proportionally. Recommended flow of thermal fluid ~40 l/m2, h Recommended inclination of the collector towards the exit of the warm fluid 1-2%. The performance curve of p. 6 refers to collectors oriented to the South, at a slope of 45o with respect to the horizontal plane. Regarding other positions, performance is slightly reduced for slope angles to 15o, while for higher angles it may reach up to 30%. The following table provides the approximate anticipated performance reductions on...

The following accessories are provided, to facilitate installation: • Supports for flat roofs • Supports for inclined tiled roofs • 018 connection fitting (022 upon special order) • Special covers for increased collector protection in the summer • Calpak thermal fluid based on non-toxic pharmaceutical propylene glycol, packaged in 1-, 2-, 5- and 10-liter canisters. • Automatic ventilators • Tee fittings, protection sockets and sensors • Full range of solar stations for controlling the operation of central solar systems, with or without circulation pump. Note: The company reserves the right to...