Analysis of Window Components Affecting U-Value Using Thermal Transmittance Test Results and Multiple Linear Regression Analysis

Table 2

Window component settings and coding of nominal scale variables for multiple linear regression analysis.

	Variables
Frame material	FR_1	FR_2	FR_3	FR_4	FR_5
Stainless steel	1	0	0	0	0
Galvanized	0	1	0	0	0
Steel	0	0	1	0	0
Aluminum	0	0	0	1	0
PVC	0	0	0	0	1
Wood	0	0	0	0	0
Window opening type	OP_1	OP_2	OP_3	OP_4	OP_5
Fixed	1	0	0	0	0
Sliding	0	1	0	0	0
Casement	0	0	1	0	0
Tilt	0	0	0	1	0
Folding	0	0	0	0	1
Turning	0	0	0	0	0
Spacer material	SP_1	SP_2	Window number	WD_1
PVC	1	0	Single	1
Aluminum	0	1	Double	0
Stainless steel	0	0