System Design - IDEAL Viceroy GT 8 Installation And Servicing

8

SYSTEM DESIGN

Minimum Water Flow
Design Flow Rates
The following table gives the flow rate required for each boiler
based on a design temperature difference of 11ºC (20ºF) at the
maximum rated output. For hydraulic resistance see
Performance Data table (page 2).
Boiler Size
Normal water flow rate
temperature difference 11ºC (20ºF) g.p.m.
Minimum water flow rate
temperature difference 35ºC (63ºF) g.p.m.
System Design
Recommendations relating to water system design are
contained in BS. 5410: Part 2 and BS. 6880.
System design must allow for adequate internal circulation
within the boiler and sufficient heat release from the boiler
body during and immediately after burner firing. Heating and/
or hot water controls should be interlocked electrically with the
burner, to prevent firing when the system does not demand
heat.
Depending on system design it may be necessary to interrupt
electrical supply to the burner before any mixing valves are
completely closed to the boiler flow. This will dissipate
residual heat. Also a pump overrun of at least 5 minutes is
required on plant shutdown to avoid interference trip out of the
overheat thermostat. If system return temperature remains
below 30ºC for most of the heating period some protection
from condensation is required.
Please contact Caradon Ideal Limited for further information.
10
GENERAL
Minimum Flow Rates
It may be necessary to fit a shunt pump to ensure minimum
flow rates.
GT 8 GT 9
l/s 8.47 9.77
111.77 128.96 154.75
l/s 2.66 3.07
35.13 40.53
Example of Installation
The example below does not cover all the possible cases of
use. It is only aimed at drawing attention to the basic rules
which must be complied with. In all events, comply with
applicable codes of practice and national or local regulations.
Example shows a sealed system with domestic hot water
production via independent calorifiers.
Typical Sealed System Example
A shunt pump sized on the minimum flow rate required MUST
be fitted. Provided adequate heat dissipation can be achieved
at all times the shunt and DHW primary pumps only may run
on during the overrun period allowing the heating pump to be
switched off. This example assumes the DHW primary pump
flow rate required is less than that required for the shunt pump.
GT 10 GT 11 GT 12
11.73 13.03 14.55
171.95 192.01
3.69 4.09 4.57
48.64 54.04 60.35
Viceroy GT -
GT 13 GT 14
15.63 16.94
206.34 223.53
4.91 5.32
64.85 70.25
Installation & Servicing