Hot Air Applications


SOLKOTE HI/SORB-II is an optical coating specifically formulated for solar thermal applications. Its high temperature tolerance, resistance to moisture and UV degradation, and excellent optical qualities make it an ideal, low cost substitute for electro or vacuum deposited selective surfaces and a far superior option to simple black paints. Its high absorptivity and strong adhesion makes it an ideal coating for all hot air collector absorber surface materials. With a proven history of reliability and longevity, SOLKOTE has powered many of the world’s largest solar thermal manufacturers’ collectors since 1980. Is your collector powered by SOLKOTE?

Cansolair Hot Air Collector

Cansolair hot air collector

SOLKOTE offers the following unique features:

  • Low cost (50 – 75% cheaper than competing selective surfaces)
  • Easy spray application (requiring very low capital investment)
  • Excellent high temperature tolerance (1000°F/538°C)
  • Excellent resistance to UV and moisture degradation
  • Excellent long term durability (does not lose absorptivity over time)
  • Excellent optical characteristics
  • Superior optics and durability to standard black paints
  • No out-gassing when correctly cured
  • May be used in low to high temperature glazed applications
  • Shipped premixed, ready to apply
  • Excellent shelf life (one year from date of mfg.)
  • Not recommended for exterior or unglazed applications

SOLKOTE HI/SORB-II is the absorber surface of choice for many of the world’s leading solar thermal manufacturers. SOLKOTE can provide superior optical properties to hot air systems for a fraction of the cost of electro or vacuum deposition and is one of the few selective surfaces in the world with a 30+ year history of in-field use. SOLKOTE is an ideal selective surface for hot air solar thermal systems. Its silicone polymers allow for coating on a wide variety of low e substrates like copper, aluminum, soda/pop cans, aluminum tubing and on cementitious materials like brick and concrete for use in trombe wall construction. SOLKOTE provides an extremely durable surface on hot air panels, with strong UV and moisture resistance and temperature tolerance to 1000F (538C). It will not degrade under severe stagnation temperatures.

Trombe Wall

Trombe wall, hot air application

SOLKOTE is a perfect technology for the solar startup because it requires minimum capital investment, a simple paint sprayer. It allows for an extremely low cost selective surface that can be applied evenly for smooth, consistent coating on puckered, roll-formed (must be applied after roll-forming process), tubular, can or accordioned absorbers. It is a maintenance free material that will provide stable optics for the life of your collector.

Optical properties are driven by surface preparation, coating thickness and substrate material. SOLKOTE must be properly cured and glazed (under glass) for best results. Please contact us at the factory for assistanceand use the form below for pricing inquiries.