Page 24
4.0 HEATING AND HOT WATER
(a)
mCHP BoilerMate
A-CLASS
is only available for sealed heating systems and the schematic
arrangement of a sealed heating system is shown in figures 2.3 and 4.2.
(b)
Model selection
: We recommend that the method for heat loss calculations, radiator
and boiler sizing contained in BS 5449:1990 is used to calculate the design heat
loss of the dwelling. This together with selection data in table 3.3 and the heating
power output of the mCHP unit should be used to determine the suitability of the
proposed system combination for the dwelling. The allowance for hot water shown
in Table 3.2 should be added to the calculated requirement for space heating.
(c) Design:
The installation must comply with the requirements of BS 6798 and BS
5449. To suit conventional radiator based central heating systems, the appliance
will normally provide the same flow temperatures as a conventional gas/oil fired
boiler system. Therefore normal procedures for sizing heating circuit network and
radiators should be used.
The pump head available for space heating and mCHP hydraulic circuits is shown
in figures 3.3 and 3.4. The appliance connection details are shown in figure 3.2
and table 3.1 in the technical specification section 3.
if the appliance is at the highest point of the system, a manual air vent is provided
on the appliance. However if any point of the heating system is higher than the
appliance, then an air vent must be fitted at the highest point in the system.
At least one flushing point should be fitted at the lowest point in the system to
enable the system water to be adequately flushed during commissioning.
(d) Frost protection:
if it is necessary, to protect the system installed in unheated spaces
(e.g. garage, outhouse and ventilated roof space), a frost thermostat(s) must be fitted
and wired as shown in sections 5 of this manual. Before fitting the frost protection,
the mCHP manual should also be consulted.
(e) User controls:
The mCHP BoilerMate
2000
models are supplied with a factory fitted 1-
channel programmer and the room thermostat must be wired back to the appliance
(see section 5).
4.2 SPACE HEATING DESIGN
Space heating circuit
CH
flow
P2
CH
rtn
1 bar
1 bar
Approved Filling Loop
Cold Raising Main
Standard Sealed heating
expansion kit to be supplied
and fitted by installer.
PRV 3 Bar
Thermal Store
Figure 4.2 Schematic diagram of the sealed heating system
Summary of Contents for mCHP BMA 225
Page 44: ......