LBNL Report Number
The thermal performance of single glazing, clear double glazing, and double glazing with a low-emissivity coating was measured in both south-facing and north-facing orientations under realistic field conditions using the new MoWiTT field test facility. The time-dependent net heat flow through each fenestration was found to be consistent with the predictions of the standard simplified heat transfer model, provided that an angle-dependent shading coefficient is used and diffuse solar gain is included in the calculation. Summer-condition average U-values were derived for each glazing type and were found to agree with the expected values for both types of double glazing. The measured U-value for single glazing was lower than predicted.