Overall Thermal Transmission Value (OTTV)
1.0 WHAT IS OTTV?
2.1 Equivalent Temperature Differential (TDeq) is the theoretical difference between outdoor and indoor temperatures that would result in a heat transfer equivalent to the effects of solar heat-gains, thermal storage and actual temperature difference on an opaque component, as a roof [unit = K];
3.1 EEBC-94 specifies the maximum OTTV for roofs as 20 W/m2 ;
|Fig. 1: Shading Coefficients for Fenestration|