The central heating system can be divided into 3 zones:
Biomass boiler zone
This zone is essentially composed of:
· 1 boiler with automatic air supply
· 1 high efficiency tandem circulation pump
· 1 three-way modulating valve with control unit to prevent water with a temperature value that is too low from returning to the boiler
· Control, expansion and safety equipment
· 1 charging unit with pressure reducing valve and backflow preventer
· Water treatment devices (dirt separator and deaerator) for the protection of generators and, more generally, all closed system components
Inertial tank zone with heating medium distribution
This zone is essentially composed of:
· 1 tank
· 1 high efficiency tandem circulation pump
· 1 three-way regulating valve with climatic controller
· Control and shut-off devices
Three typical operating situations may occur:
· Biomass boiler on and distribution circulator off: the heat produced by the wood-fired boiler brings the water storage tank to temperature;
· Biomass boiler on and distribution circulator on: the heat produced by the wood-fired boiler is conveyed to the distribution system;
· Biomass boiler off and distribution circulator on: the distribution system utilises the heat stored previously in the water storage tank.
The temperature of the water supplied to the radiators can be regulated with a climatic curve.
This configuration can also be applied in medium-large systems; in this case the devices for closed vessel systems should not be installed.
Domestic hot water production and distribution zone
This zone is essentially composed of:
· 1 tank, with high heat exchange surface area, for the production and storage of domestic hot water
· 1 high efficiency tandem circulation pump
· Devices and equipment for regulation and for supplying DHW to the various users
Domestic hot water production is controlled by a thermostat which activates or deactivates circulation of the heating medium through the tank heat exchanger.
If necessary, or if required by current legislation, the system must be equipped with a specific treatment system for the domestic water to be heated, in relation to water hardness and projected consumption rates.
Note:
The control, expansion and safety equipment must be of appropriate size to reflect the heating capacity and specific characteristics of the system, in accordance with applicable laws and regulations.
