6
Hydronic piping
(continued)
It is recommended that near boiler
piping systems utilize
Primary/Secondary
configurations as shown in FIG.’s 6-3
through 6-9 only. The use of other near
boiler piping configurations could result in
improper building and system flow rates
leading to inadvertent boiler high limit
shutdowns and poor system performance if
proper pump sizing and system flow rates are
not adhered to.
NOTICE
Pump sizing and flow requirements are
based on 20 feet of piping, 4 - 90° elbows,
and 2 - fully ported ball valves.
NOTICE
Variable speed pump option
Table 6B Recommended Variable Speed Pumps
Variable speed pumping to maintain a set differential temperature (
Δ
T) between two (2) sensors allows for the following:
-
Automatic adjustment of the pump's performance to match the low of the system or zone
-
Eliminate velocity noise in the zone valve systems
- Conserve
energy
Since
Δ
T is directly releated to flow rate, the pump's speed continually adjusts to the required BTU per hour. In almost all
applications the design of the system was based on being able to maintain a certain
Δ
T and figured by using the universal
hydronics equation of BTU/hr = GPM x 500 x
Δ
T. Given that, any time there is a change to the heat load (i.e., warmer day
or greater heat loss from a structure) then the GPM should change to match the required BTU/hr. This is achieved when the
variable speed circulators automatically and continually adjust their GPM output (by varying speed) to match the required
BTU/hr output of the system, no matter the changes in heat load, while always maintaining the designed
Δ
T between a supply
and return sensor.
Variable speed pump setup
Before operation, ensure the following:
- Pump is set for an input signal of 0 - 10Vdc by the dip switches on the pump control
- Pump is set for external signal control (if applicable)
- Pump is set for linear output (if applicable)
- If pump does not come equipped with a 0 - 10 Vdc input option, an optional module
will be required from the vendor
37
Installation & Operation Manual
0.00
3.00
6.00
9.00
12.00
15.00
18.00
21.00
24.00
27.00
30.00
33.00
36.00
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
FT
/H
D
FLOW
VFD PUMP
155
199
285
399
UPS26-96FC/VS
TACO 0013 IFC VS
UPS26-96 FC/VS 50%
TACO 0013 IFC VS 50%
SMART SYSTEM / Multi-temperature loop
control option
The Knight wall mount boiler is capable of producing up
to three (3) set point temperatures to meet different space
heating demands. When using more than one temperature
demand it is necessary to protect the lower temperature
loop from overheating. To help aid with this protection,
Lochinvar offers the Multi- Temperature Loop Control Board
Kit (RLY30086).
