Greenhouse Heating Requirements: Table 1

Greenhouse Heating Requirements: Table 1

Heat Transfer Coefficient for Greenhouse Construction Materials

Material	BTU/sq ft - o F - hr
1. Glass, single layer	1.13
2.Glass, double layer,1/4" space	0.65
3. PE film, single layer	1.15
4. PE film, double layer, seperated	0.70
5. Fiberglass	1.00
6. Concrete block, 8"	0.51
7. Concrete block, 8" plus 1" foam urethane	0.13
8. Concrete block, 8" plus 1" foam polystyrene	0.18
9. Concrete poured, 6"	0.75
10. Cememt asbestos board, 1/4"	1.10
11. Cement asbestos board, 1/4" plus 1" foam urethane	0.14
12. Cement asbestos board, 1/4" plus 1" foam poly styrene	0.21

(The smaller the U value the lower the heat loss)