Heating And Hot Water System Design; Hot And Cold Water System - Benchmark mCHP BoilerMate Design, Installation And Servicing Instructions

4.0 HEATING AND HOT WATER
4.1 HEATING AND HOT
WATER SYSTEM DESIGN
(a) All recommendations with regard to pipe work systems in this manual are generally
based on the use of BS/EN Standard copper pipework and fittings.
(b)However the plastic pipework system can be used in place of copper internally as
long as the chosen system is recommended by the manufacturer for use in cold
and hot water systems and is fully designed and installed in accordance with their
recommendations.
(c) This is particularly important in relation to use of push fit connections when
using the optional flexible hose kits (See Installation and Wiring section of this
document).
(d)It is also important that if an alternative pipework material or system is chosen,
then, the manufacturer confirms that the design criterion for the new system is at
least equivalent to the use of BS/EN Standard copper pipework and fittings.
Second
Pressure limiting valves NOT
dwelling
REQUIRED at pressures
below 5 bar if terminal
fittings have flow regulators
fitted
Sink
H C
Check valve NOT REQUIRED unless
chemical water treatment unit is fitted
M.C.W.S Double check valve NOT REQUIRED unless supply
supply pipe pipe services more than one dwelling
Figure 4.1 Typical hot and cold water distribution pipework in a dwelling
4.1.1 MAINS PRESSURE AND WATER SUPPLY
(a) mCHP_BoilerMate is designed to be connected directly to the mains and fulfil
the requirements of Water Byelaw 91 and therefore do not require a check valve
to be fitted to the supply pipe. However, should ancillary equipment requiring a
non-return valve, is to be fitted to the same mains supply as the BoilerMate, then
this valve must not be fitted between the inlet of this mains supply to the property
and the BoilerMate (see figure 4.1).
(b) The hot water flow rate achievable from the BoilerMate and the performance of
the domestic hot and cold water systems is directly related to the adequacy of
the cold water mains serving the property. For this reason the cold water supply
to the dwelling must be capable of providing for those services which could be
required simultaneously and this maximum demand should be calculated. Also if
a water meter is fitted its nominal rating should match the anticipated maximum
simultaneous hot and cold water demand calculated in accordance with BS 6700.
This could be 50 litres per minute in some properties.
(c) All models of the mCHP BoilerMate will operate at pressure as low as 1 bar but the
recommended range is between 2 and 3 bar. These pressures must be dynamic
and be available at the appliance when local demand is at its maximum.
Supplied By www.heating spares.co Tel. 0161 620 6677
Gate Valve - can be used to isolate in case
of maintenance or to restrict the total flow
rate if flow restriction is not provided
Scale inhibitor
IF REQUIRED
Bath
H C
a
'a'
- flow regulator recommended for better
balance of hot and cold water supplies
Hand
basin
H C
a a a
(d) As a general guideline, although a 15mm
service may be sufficient for smaller
dwellings with one bathroom, a 22mm
service (25mm MDPE) is preferred and
should be the minimum for larger
dwellings.
(e) If the incoming mains pressure exceeds
5 bar at any time in a 24 hour cycle, then,
a pressure regulating valve set at 3.5 bar
should be fitted down stream of the stop
tap where the cold supply enters the
property.
(f ) Equipment used in the system should be
suitable for a working pressure of up to
5bar.
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