54 UH-SVX01A-EN
Hot Water Performance Data
To obtain the BTU capacity for conditions other than those in the basic capacity tables, multiply the basic rating (200° entering water, 60° entering air) by the proper constant
from the above tables.
Table 38. HOT WATER CONVERSION FACTORS BASED ON 200° ENTERING WATER 60° ENTERING AIR 20° TEMPERATURE DROP
ENTERING AIR
TEMPERATURE
°F (°C)
ENTERING WATER TEMPERATURE -20° WATER TEMPERATURE DROP
100°
(38°)
120°
(49°)
140°
(60°)
160°
(71°)
180°
(82°)
200°
(93°)
220°
(104°)
240°
(116°)
260°
(127°)
280°
(138°)
300°
(149°)
30° (-1) 0.518 0.666 0.814 0.963 1.120 1.268 1.408 1.555 1.702 1.850 1.997
40° (4) 0.439 0.585 0.731 0.878 1.025 1.172 1.317 1.464 1.609 1.755 1.908
50° (10) 0.361 0.506 0.651 0.796 0.941 1.085 1.231 1.375 1.518 1.663 1.824
60° (16) 0.286 0.429 0.571 0.715 0.857 1.000 1.143 1.286 1.429 1.571 1.717
70° (21) 0.212 0.353 0.494 0.636 0.777 0.918 1.060 1.201 1.342 1.483 1.630
80° (27) 0.140 0.279 0.419 0.558 0.698 0.837 0.977 1.117 1.257 1.397 1.545
90° (32) 0.069 0.207 0.345 0.483 0.621 0.759 0.897 1.035 1.173 1.311 1.462
100° (38) 0 0.137 0.273 0.409 0.546 0.682 0.818 0.955 1.094 1.230 1.371
Table 39. HOT WATER BTU, GPM AND PRESSURE LOSS FACTORS BASED ON STANDARD CONDITIONS OF 200°F ENTERING WATER 60°F ENTERING AIR & 20°F WATER DROP
USE FACTORS FROM THIS TABLE TO OBTAIN
APPROXIMATE RESULTS
TEMPERATURE DROP °F (°C)
5 (3) 10 (6) 15 (8) 20 (11) 25 (14) 30 (17) 40 (22) 50 (28) 60 (33)
To obtain BTU for other Water Temperature Drops,
multiply basic BTU rating by applicable Factor.
1.25 1.15 1.08 1.00 .94 .90 .83 .76 .72
To obtain GPM for other Water Temperature Drops,
multiply basic GPM rating by applicable Factor.*
5.00 2.30 1.44 1.00 .74 .59 .40 .30 .24
To obtain Pressure Loss Feet of Water for other
temperature Drops, multiply Basic loss at 20° drop by
Factor.
10.00 5.00 2.00 1.00 .60 40 .20 .13 .07
Table 40. *MINIMUM WATER FLOW - GPM
MODEL No. 42 64 80 102 146 166 202 252 336 384
MIN. GPM (L/s) .55
(.035)
.55
(.035)
.55
(.035)
.55
(.035)
.82
(.052)
.82
(.052)
1.10
(.069)
1.10
(.069)
1.10
(.069)
1.10
(.069)
Table 41. *HEATING CAPACITY FACTORS FOR VARIOUS RATES OF WATER FLOW
% of Rated Water Flow 25% 50% 75% 100% 125% 150% 175%
Btu/Hr Heating Capacity .80 .89 .96 1.00 1.04 1.07 1.10