Sterling HS - Manual (Page 8)

8
To obtain output for other Water Temperature Drops,
multiply basic output rating by applicable Factor.
To obtain fl ow for other Water Temperature Drops,
multiply basic rate rating by applicable Factor.*
To obtain Pressure Loss Feet (Meters) of Water
for other temperature Drops, multiply Basic loss
at 20°F (11°C) drop by Factor.
MODEL No.
MINIMUM
GPM (L/s)
MODEL No.
MINIMUM
GPM (L/s)
EXAMPLE: –
UNIT SIZE: _______________________ 24
Entering Water Temp. ____________ 160°F
Entering Air Temp. _______________ 40°F
Water Temperature Drop __________ 10°F
I. CAPACITY @ 20° TD:
A. For 200° EWT, 60° EAT Read output directly from Table 6,
17,400 BTU/HR (Ref., Std. 24).
B. For EWT and/or EAT above Multiply output from Table 6
or below Standard by factor from Table 7 (below). 17,400 x .878 = 15,277 BTU/HR.
II. CAPACITY AT OTHER TD’s Multiply output obtained in IA. or IB. IA - 17,400 x 1.15 = 20,010 BTU/HR.
A. For TD’s from 5 to 60°F (above) by appropriate factor from Table 8 – OR –
(below) IB - 15,277 x 1.15 = 17,569 BTU/HR.
III. GPM AT OTHER TD’s Multiply GPM of unit for 20° TD, from Table 6 1.8 x 2.30 = 4.14 GPM (Applies only to units with
A. For TD’s from 5 to 60°F by appropriate factor from Table 8 (below). Std. 200° EWT, 60° EAT.) For all others calculate
BTU
using formula – GPM =
500 x TD
IV. CAPACITY AT OTHER RATES Multiply output from Table 6 by factor
OF WATER FLOW from Table 10 (below).
V. PRESSURE LOSS AT OTHER TD’s Multiply P.D. of unit for 20° TD, from Table 6
A. For TD’s from 5 to 60°F by appropriate factor from Table 8 (below). .014 x 5.00 = .07 Ft. H
2
O
100°
(38)
0.518
0.439
0.361
0.286
0.212
0.140
0.069
0.000
120°
(49)
0.666
0.585
0.506
0.429
0.353
0.279
0.207
0.137
140°
(60)
0.814
0.731
0.651
0.571
0.494
0.419
0.345
0.273
160°
(71)
0.963
0.878
0.796
0.715
0.636
0.558
0.483
0.409
240°
(116)
1.555
1.464
1.375
1.286
1.201
1.117
1.035
0.955
260°
(127)
1.702
1.609
1.518
1.429
1.342
1.257
1.173
1.094
TABLE 7 — HOT WATER CONVERSION FACTORS BASED ON 200° (93°C) ENTERING WATER,
60° (16°C) ENTERING AIR AND 20° (11°C) TEMPERATURE DROP
TABLE 8 — HOT WATER OUTPUT, FLOW RATE AND PRESSURE LOSS FACTORS BASED ON STANDARD
CONDITIONS OF 200°F (93°C) ENTERING WATER, 60°F (16°C) ENTERING AIR & 20°F (11°C) WATER DROP
*TABLE 9 — MINIMUM WATER FLOW
*TABLE 10 — HEATING CAPACITY FACTORS FOR VARIOUS RATES OF WATER FLOW
ENTERING AIR
TEMPERATURE
°F (°C)
30 -(1)
40 (4)
50 (10)
60 (16)
70 (21)
80 (27)
90 (32)
100 (38)
ENTERING WATER TEMPERATURE — °F (°C)
180°
(82)
1.120
1.025
0.941
0.857
0.777
0.698
0.621
0.546
200°
(93)
1.268
1.172
1.085
1.000
0.918
0.837
0.759
0.682
220°
(104)
1.408
1.317
1.231
1.143
1.060
0.977
0.897
0.818
280°
(138)
1.850
1.755
1.663
1.571
1.483
1.397
1.311
1.230
300°
(149)
1.997
1.908
1.824
1.717
1.630
1.545
1.462
1.371
5
(3)
1.25
5.00
10.00
25
(14)
.94
.74
.60
30
(17)
.90
.59
.40
20
(11)
1.00
1.00
1.00
60
(33)
.72
.24
.07
40
(22)
.83
.40
.20
50
(28)
.76
.30
.13
TEMPERATURE DROP °F (°C)
USE FACTORS FROM THIS TABLE TO OBTAIN
APPROXIMATE RESULTS
96
3.350
(.211)
132
4.09
(.258)
360
6.08
(.384)
300
6.08
(.384)
72
1.620
(.102)
84
1.860
(.117)
125A
0.125
(.008)
60
1.490
(.094)
280
4.59
(.290)
48
1.490
(.094)
240
4.59
(.290)
204
4.34
(.274)
36
1.240
(.078)
180
4.34
(.274)
24
1.240
(.078)
156
4.09
(.258)
18
0.750
(.047)
144
4.09
(.258)
136A
0.125
(.008)
118A
0.125
(.008)
120
3.60
(.227)
108A
0.125
(.008)
108
3.35
(.211)
175%
1.10
25%
.80
75%
.96
125%
1.04
150%
1.07
50%
.89
% of Rated Water Flow
Heating Capacity Factor
100%
1.00
10
(6)
1.15
2.30
5.00
15
(8)
1.08
1.44
2.00
HOT WATER CALCULATIONS AND CORRECTION FACTORS