Hot Water Sizing Method For Mixing Valve Selection - resideo MX Serie Instrucciones De Instalación

Hot Water Sizing Method For Mixing Valve Selection

1. Determine Fixture Units – Table 2
2. Using Total Fixture Units determine load in Gpm from Table 3.
3. Select product based on minimum flow requirement and allowable pressure drop (20 Psi).
Fixture Units
Fixture Private
Lavatory 1
Kitchen Sink 2
Bathtub 2
Separate Shower 2
Clothes Washer 2
Dish Washer 1
EXAMPLE: A system with 40 Lavatory (Private), 40 Bathtubs (private) and 5 Lavatory (public) has total fixture count of 130
fixture units. From Table 3 - 130 fixture unit = 38 Gpm
Fixture Units
2 2
6 4.5
10 6.5
14 8.5
20 11
24 13
30 15
34 16.5
40 18.5
45 20
50 21
Min Flow
Product GPM
MX127LF 1
MX128LF 2.5
MX129LF 3.5
MX130LF 5
MX131LF 8
MX132LF 12
This sizing method is a general guideline. Please refer to local building and plumbing codes for additional guidance.
Table 2. Fixture Unit Worksheet.
Public # of Fixtures
2
4
4
4
4
2
Table 3. Domestic Hot Water Demand – Load Data.
Gpm Fixture Units
55
60
70
80
90
100
130
160
200
260
300
Table 4. Single High Capacity MX Series Mixing Valve Selection Chart
Outlet Size
Inch 5
1" 9
1¼" 21
1½" 30
2" 40
2½" 76
3" 112
MX SERIES COMMERCIAL MIXING VALVES
Fixture Unit Calculation
(multiply by) Fixture Units
x
x
x
x
x
x
Gpm
23
24
27
29
31
33
38
43
49
58
64
System Differential Pressure Drop (PSI)
10 15
13 15
29 36
43 52
57 70
108 132
158 194
5
Equals Total
=
=
=
=
=
=
Total
Fixture Units
350 72
400 78
450 86
500 93
550 100
600 107
650 115
700 122
750 130
800 134.5
1000 156
20 25
18 20
42 47
60 68
80 90
152 170
224 250
Gpm
30
22
51
74
99
186
274
38-00034EFS—03