Output classes Technological level
AAA/AA In order to reach the classes AA and AAA it is necessary to have additional AA features such as double glazing, vacuum isolation or reflectors.
A+++ Flat plate collectors of the “premium” class and vacuum tube collectors with little distance between the tubes and without reflector
A++ Flat plate collectors of the “comfort” class and vacuum tube collectors with bigger space between the tubes
A Simple collectors and vacuum tube collectors with considerable big space between the tubes or weak technical heat properties
A– Very simple flat plate collectors which comply with the minimum requirements
for getting grants, as well as vacuum tube collectors with extreme space between the tubes and non-selective flat plate collectors