Install Instructions

IM-PR 566442 1114 (Design Manual)
202
Appendix H Btu output tables
This appendix contains charts that show the relationship between heating load supplied by radiant floors
(Btu/hr/ft
2
of floor area) and the supply water temperature to the floor, based on the R-value of floor
coverings. Tables are provided for floor applications (thin-slab, slab on grade, Climate Panels, Climate
Trak and Heat Transfer Plates). To use the tables, follow this procedure:
1. Determine the floor type and tubing spacing.
2. Determine the finish floor’s (e.g., carpet and pad, hardwood, ceramic tile, etc.) R-value (Rff).
3. Select the appropriate Btu output table based on the floor type.
4. Determine the upward heat flux (qu), based on the average water temperature in the tubing at the
design load (Tw).
Example
Floor type: Thin-slab, 6" o.c. spacing
Finish floor R-value: Rff = 0.5 hr*ft
2
*°F/Btu
Average water temperature in the tubing at the design load: Tw= 110°F
Upward heat flux: qu = 31.1 Btu/hr/ft
2
Thin-Slab Upward Heat Flux (Btu/hr/ft²)
T
w
(°F)
R
ff
=0 R
ff
=0.5 R
ff
=1.0 R
ff
=1.5 R
ff
=2.0
6"
o.c.
9"
o.c.
12"
o.c.
6"
o.c.
9"
o.c.
12"
o.c.
6"
o.c.
9"
o.c.
12"
o.c.
6"
o.c.
9"
o.c.
12"
o.c.
6"
o.c.
9"
o.c.
12"
o.c.
80 14.4 11.6 11.5 8.9 7.9 7.8 6.5 5.9 5.3 5.2 4.8 4.3 4.2 4.0 3.7
85 20.4 16.5 16.3 12.6 11.2 11.1 9.2 8.3 7.5 7.3 6.8 6.1 6.0 5.6 5.3
90 26.4 21.3 21.1 16.3 14.5 14.3 11.9 10.8 9.7 9.5 8.8 7.9 7.7 7.3 6.8
95 32.4 26.2 25.9 20.0 17.8 17.6 14.6 13.2 11.9 11.6 10.8 9.7 9.5 8.9 8.4
100 38.4 31.0 30.7 23.7 21.1 20.8 17.3 15.7 14.1 13.8 12.8 11.5 11.2 10.6 9.9
105 44.4 35.9 35.5 27.4 24.4 24.1 20.0 18.1 16.3 15.9 14.8 13.3 13.0 12.2 11.5
110 50.4 40.7 40.3 31.1 27.7 27.3 22.7 20.6 18.5 18.1 16.8 15.1 14.7 13.9 13.0
115 56.4 45.6 45.1 34.8 31.0 30.6 25.4 23.0 20.7 20.2 18.8 16.9 16.5 15.5 14.6
120 62.4 50.4 49.9 38.5 34.3 33.8 28.1 25.5 22.9 22.4 20.8 18.7 18.2 17.2 16.1
125 68.4 55.3 54.7 42.2 37.6 37.1 30.8 27.9 25.1 24.5 22.8 20.5 20.0 18.8 17.7
130 74.4 60.1 59.5 45.9 40.9 40.3 33.5 30.4 27.3 26.7 24.8 22.3 21.7 20.5 19.2
135 80.4 65.0 64.3 49.6 44.2 43.6 36.2 32.8 29.5 28.8 26.8 24.1 23.5 22.1 20.8
140 86.4 69.8 69.1 53.3 47.5 46.8 38.9 35.3 31.7 31.0 28.8 25.9 25.2 23.8 22.3
145 92.4 74.7 73.9 57.0 50.8 50.1 41.6 37.7 33.9 33.1 30.8 27.7 27.0 25.4 23.9
150 98.4 79.5 78.7 60.7 54.1 53.3 44.3 40.2 36.1 35.3 32.8 29.5 28.7 27.1 25.4
155 104.4 84.4 83.5 64.4 57.4 56.6 47.0 42.6 38.3 37.4 34.8 31.3 30.5 28.7 27.0
160 110.4 89.2 88.3 68.1 60.7 59.8 49.7 45.1 40.5 39.6 36.8 33.1 32.2 30.4 28.5
Table F-1 Upward heat flux (qu) for a thin-slab, given as a function of finished floor R-value (Rff), tubing
spacing (6, 9 or 12" on center) and average water temperature in tubing (Tw). Assumes 68°F room
temperature and adequate insulation.