Installation Instructions: Hydraulic Connections; Centralised System Requirements - Baxi LUNA SAT RCZ G1-MB Installation And Operating Manual

3. CENTRALISED SYSTEM REQUIREMENTS

Some general indications concerning the installation of the centralised heating system are shown below. For
these types of plants, a cutting-edge bespoke design is always necessary in order to ensure ideal conditions of
comfort, save energy and reduce the environmental impact.
Install the boilers in a cascade arrangement (preferably condensation boilers with low pollutant emissions) of a suitable
size to optimise plant performance according to seasonal loads, user demand and Domestic Hot Water demand peaks.
The maximum installed power must consider a simultaneous use factor so as not to oversize the generator and conse-
quently reduce operating efficiency.
The centralised plant must service the various floors of the building by means of columns positioned in the stairwells or
in utility rooms which should preferably be inspectable.
A hydraulic separator should always be fitted downline from the heat generator as this separates circulation in the gene-
rator from circulation in the columns.
The centralised plant must have the following features:
• Automatic filling
• Expansion system sized according to total plant capacity
• Overpressure safety valve sized according to current legislation
Each suitably sized column must be fitted with a circulator (preferably at variable speed depending on the demand of the
modules), on/off valves and a dynamic balancing valve. Automatic air vents must be installed at the top of the columns.
The inlet sections must have the same pressure drop in order to allow the system to balance feed to all the user systems.
The recommended typology is three columns with a reverse return line.
The columns and manifolds must be well lagged.
The heating circuit pressure drops downline from the user module (R = 0.3 KPa/m per linear metre + local pressure drops)
and the pressure drop of the module itself must also be considered when calculating the pressure drops.
A by-pass valve can be fitted if the system is not fitted with a modulating pump.
If the system also operates in the cooling mode, a chilled water refrigeration system must be installed in parallel with the
heat generator. The piping must be sized according to the greater of the two loads (winter or summer). The piping must
be suitably lagged to prevent the humidity in the air from condensing on the cold surfaces.
INSTALLATION AND OPERATING MANUAL
INSTALLATION INSTRUCTIONS:
HYDRAULIC CONNECTIONS
32
7215037.01 - en