Thermal Insulation Performance of Radiant Barrier Roofs for Rural Buildings in the Qinba Mountains

Table 3

Outdoor sol-air temperatures on the winter solstice.

Temperature on the winter solstice (°C)
Time	Level	South	East	Western	North	Outdoor air
1 : 00	−4.3	−2.25	−2.25	−2.25	−2.25	−0.2
2 : 00	−4.68	−2.64	−2.64	−2.64	−2.64	−0.6
3 : 00	−4.88	−2.84	−2.84	−2.84	−2.84	−0.8
4 : 00	−4.86	−2.83	−2.83	−2.83	−2.83	−0.8
5 : 00	−4.65	−2.62	−2.62	−2.62	−2.62	−0.6
6 : 00	−4.53	−2.52	−2.52	−2.52	−2.52	−0.5
7 : 00	−4.54	−2.52	−2.52	−2.52	−2.52	−0.5
8 : 00	−4.65	−2.62	−2.62	−2.62	−2.62	−0.6
9 : 00	−2.98	−1.3	−1.23	−1.73	−1.73	−0.7
10 : 00	−0.8	0.21	0.04	−0.58	−0.58	−0.8
11 : 00	1.2	1.56	1.06	0.62	0.62	−0.6
12 : 00	2.21	2.12	1.56	1.43	1.43	−0.2
13 : 00	0.56	0.96	0.88	0.89	0.88	0.4
14 : 00	−0.42	0.61	0.59	0.6	0.59	1.1
15 : 00	0.01	1.15	1.12	1.14	1.12	1.8
16 : 00	−0.37	1.18	1.14	1.18	1.14	2.4
17 : 00	−1.27	0.76	0.76	0.76	0.76	2.8
18 : 00	−1.18	0.86	0.86	0.86	0.86	2.9
19 : 00	−1.19	0.86	0.86	0.86	0.86	2.9
20 : 00	−1.28	0.76	0.76	0.76	0.76	2.8
21 : 00	−1.44	0.58	0.58	0.58	0.58	2.6
22 : 00	−1.92	0.09	0.09	0.09	0.09	2.1
23 : 00	−2.31	−0.3	−0.3	−0.3	−0.3	1.7
0 : 00	−2.21	−0.2	−0.2	−0.2	−0.2	1.8
Average	−2.1	−0.46	−0.51	−0.58	−0.58	0.77