Dynamic Heat Reduction (DHR)
A complimentary solution for the NIR wavelength range is the Dynamic Heat Reduction (DHR).
This coating has almost no change of optical parameters at the visible range. However, within the NIR wavelength range, its IR absorption varies according to the incident optical light. Higher the solar radiation reaching the filter and higher its absorption will be. When solar radiation decreases, the IR absorption decreases as well. The DHR is a passive coating/ film triggered only by the solar radiation itself.
The combination of the two filters, DSF (Dynamic Sunlight Filter) and DHR, can provide an overall dynamic solution, when solar radiation transmittance varies according to the environmental conditions in a passive way.