How do Sunda collectors compare to “double glass wall” products?
In Sunda evacuated tubes the absorber surface and heat pipe reside in the vacuum environment, which prevents any deterioration in long-term performance. This is not the case with the double glass wall tubes in which both absorber and heat pipe are open to ambient air. Being exposed to air, the copper to aluminum interface between absorber plate and heat pipe is subject to oxidation which may lead to degraded performance over time. Double glass wall tubes are also subject to collection of water from condensation which could freeze and break glass tubes in frost prone environments. These concerns are not applicable to the Sunda design.
