2.1. Solar filters:

Solar filters are glazing systems what are single and multilayer oxide films which have high reflectance for near infrared radiation (NIR) and high transmittance for visible (VIS) light. These properties would contribute to low heat gain and undiminimished luminosity inside the building respectively. Some example of such films include: Sns — Cu2s, Sn3-Al/Al, Sn O2, Cu2 O, Bi2 O3, In2 O3, Fe2 O3, Fe O, etc [59-60].

2.2. Selective thin films:

Studies in electrochemical and optical properties of materials show that there are some metal halide and halogenate materials which are capable of modulating the transmission- reflection/scattering capabilities of pure window glasses with respect to wavelength, causing the glazing system to achieve variable transmission modes depending on the indoor needs of the buildings [62-64]. Such films can also act as photo-optical or solar filters. It can as well be used to achieve cooling/heating of building interiors, while at the same time able to deliver acceptable daylighting level into the building. This work examines some of these types of films with a view to finding their optical performance and the optical parameters that are important in this application.