Optical performance of single and double glazing units in the wavelength 337-900Â nm

Optical properties of glazing units play an important role in the quantificational analysis of solar ray and thermal transfer process in single and double glazing units. In the present work, a spectroscopic method was developed to determine the optical constants of float glass material including refractive index and absorption coefficient based on the transmittance spectra modeling. The transmittance spectrograms of single float glass glazing units at normal incidence with different glass thicknesses in the wavelength 337-900 nm were measured. Then the optical properties of single and double glazing units were numerically investigated. The results show that the optical performance of glazing units reveals a considerable difference in the measured wavelength region. The spectrum profiles of glazing units are very similar in shape, and the shapes of the spectra are not relevantly affected by the glass thickness. However, the thicker the glass layer, the weaker the transmittance and reflectance, and the stronger the absorptance.