Pipe Sizing - heat-timer VSP Installation & Operating Instructions Manual

INJECTION PIPE AND PUMP SIZING CHARTS
To determine the proper Injection Piping Size and appropriate pump, it is necessary to know the following four items:
Primary Loop Temperature - This is the temperature the Primary loop will maintain.
Secondary Loop Temperature - This is the design temperature for the Secondary loop. If an outdoor reset function
is being employed, this is the required temperature of the Secondary loop under maximum load.
Delta T of the Secondary Loop - This is the design drop in temperature through the Secondary loop. In most radiant
heat applications, the Delta T is 10. Other types of radiation, such as baseboard, have a higher design Delta T.
Maximum Injection BTUs - This is the maximum heat requirement of the Secondary loop. The Maximum Injection
BTUs is based on the Injection pump running at the highest speed. As the pump speed is reduced, fewer BTUS will
be delivered to the system.
EXAMPLE:
Primary Loop Temperature
Secondary Loop Temperature
Delta T Secondary Loop
Maximum BTUs Required
First calculate the Primary Loop Temperature minus the Secondary Loop Temperature:
140 - 100 = 40
The Delta T of the Secondary Loop is 10
Checking the first chart (Pipe Size 1/2", Globe V alve 20%) the intersection of the row marked 40 (Primary - Secondary
loop temp) and the column marked 10 (Delta T) provides 50,000 as the maximum amount of BTUs. This is too low.
Move on to the next chart.
Checking the second chart (Pipe Size 1/2", Globe Valve 100%) the intersection of the two values provides 112,500 as
the maximum amount of BTUs. This is too low. Move on to the next chart.
Checking the third chart (Pipe Size 3/4", Globe Valve 100%) the intersection of the two values provides 212,500 as the
maximum number of BTUs. This is just slightly more than the required Maximum BTU value. Use 3/4" Injection piping
with any of the following pumps: Taco 007, Grundfos 15-42, B&G NRF22.
Inj ection Piping Size 1/2"
Globe Valv e Opening 20%
Primary Loop
Temperature
minus
Secondary Loop
Temperature
Inj ection Piping Size 1/2"
Globe Valv e Opening 100%
Primary Loop
Temperature
minus
Secondary Loop
Temperature
140°F
100°F
10°F
200,000
Delta T of Secondary Loop
10
100
110,000
80
90,000
60
70,000
40
50,000
20
30,000
10
20,000
Delta T of Secondary Loop
10
100
247,500
202,500
80
157,500
60
40 112,500
20
67,500
10 45,000
15 20
115,000 120,000
95,000 100,000
75,000 80,000
55,000 60,000
35,000 40,000
25,000 30,000
15 20
258,750 270,000
213,750 225,000
168,750 180,000
123,750 135,000
78,750 90,000
56,250 67,500
4
Typical
Pump Models:
Maximum
Taco 007
Injection
Grundfoss 15-42
BTUs
B&G NRF22
Typical
Pump Models:
Maximum
Taco 007
Injection
Grundfoss 15-42
BTUs
B&G NRF22