RVR Energy Technology MICROMAT EC 45, Instruction For Usage, Installation & Commissioning, Page: 22 / 56

22
16.0 hydraulic system
design
E n e r g y T e c h n o l o g y
Ltd.
The MICROMAT EC boiler can be operated to serve a heating load in a number of ways:
1. Constant flow temperature, with the option to set either high temperature (85
°
C), medium temperature (75
°
C)
or low temperature (55
°
C).
2. Direct-on-boiler weather compensated flow temperatures, with adjustable maximum flow temperature.
3. Underfloor heating coils via a VT mixing valve with a maximum flow temperature of 55
°
C plus a second circuit
(eg. radiators) operating with direct-on-boiler weather compensated temperatures.
Flow to return drop (
∆
t). The microprocessor controls monitor return temperature and the facility to dictate a set
∆
t
(by pump speed modulation) is a standard and most important feature and will maintain the
∆
t across the boiler at
20
°
C, as the lower the return temperature, the higher the operating efficiency. HT and MT systems should be
designed for
∆
t 20
°
C and LT (underfloor coils via a mixing valve) systems
∆
t 10
°
C. Designing for a
∆
t 20
°
C gives
the added cost saving advantage of smaller pipe sizes and pumps.
The MICROMAT EC includes ‘in built’ primary pumps with a residual head pressure as listed below.
• Appliances may be installed as single units or in multiples.
• Single units may or may not require additional system pumps which will be dictated by the system configuration
and by the index resistance.
• Multiple units (and single units which require additional pumps), should always be installed with a low loss
mixing header or similar arrangement - see table below.
• The MICROMAT EC boiler has in built domestic hot water (remote stored) temperature control ability, and
if required, the in built pumps may be used to provide the primary flow to a nearby indirect cylinder or calorifier
with the boiler controlling a diverter valve in the main flow or return pipework.
• BS 6644 Requires that the following devices shall be installed, and provision within the system design must
allow for: Low water pressure cut off device, water pressure gauge and a temperature gauge.
The following system schematics show a number of typical installation types to which the MICROMAT EC boiler
may be connected.
The MICROMAT EC is not limited to just the systems shown, and may be used in conjunction with many commercially
available control items.
For further advice or guidance on schematic designs or control options contact RVR Ltd.