The centralised integrated heating system is build up around a highly efficient condensing multicell gas boiler, which supplies centralised heating for domestic hot water and space heating purposes. The system consists of 6 parallel-connected modules, each with a minimum and maximum capacity of 10 kW and 50 kW, respectively. Thereby the entire system has thermal power that can vary from 10 to 300 kW. The condensing multicell furnace has additional beneficial characteristics:

• low Nox emissions, reduced CO₂ emissions, avoided CO and CnHn emissions
• reduction of the operation/stop cycles 
• possibility to cover the real heat demand thanks to linear modulation
• burner with double fire grate
• automatic regulation of combustion gas

Multicell furnace

The multicell furnace is supplemented with satellite units (“modusat”) in each apartment and these accomplish the same tasks of space heating and hot water production as the original autonomous boilers, just without combustion. The units are supplied both by the solar system and the centralised boiler, and are all provided with a heat meter connected to the energy management system.

Extensive insulation of the building envelope and a high radiator capacity in the dwellings enables the boiler system to supply the radiators with a low water temperature of 45°C, which enhances the thermal efficiency of the condensing boiler. The existing radiators were substituted with aluminium ones in order to install the thermostatic valves, which ensure autonomous management for each apartment that suits individual temperature preferences.

Solar collectors, a total of 135 m² supplement the boiler. Each solar unit is provided with a local storing heat exchanger. Some 10 m² of photovoltaic (PV) modules, placed on the roof of one of the buildings, supply some of the electricity for the solar collector system pumps. An inverter converts the current produced by PV-modules into a standard voltage and a battery system is installed to guarantee the working of the PV -system in less sunny days.

Water solar collectors on the roof

General information on the technologies:
Gas condensing boiler
Central Heating
Solar Collectors
PV-modules
Insulation
Energy Efficient Glazing

Suppliers of technology:
Roughly the heating system can be divided into the boiler system, the solar energy system, and the insulation measures. The french company, Geminox, has supplied the multicell condensing gas boiler system, Chromagen the solar elements, heat meters from Kundo, and radiator valves by Caleffi. 

Solar energy:
Chromagen www.chromagen.co.il
Chromagen is an Israeli company that specialises in the design, manufacturing and distribution of all solar energy equipment for domestic, commercial and industrial use. PV-modules are offered in systems based on modules from Siemens (www.siemenssolar.com).
Address: Kibbutz Shaar Haamakim, IL-30097
Phone: 972 4 9839476 Fax: 972 4 9839246
e-mail: chromgn@netvision.net.il

Condensing gas boiler:
Geminox www.geminox.com
Geminox is a French steel boiler manufacturer with a product range of boilers that run on oil, gas, wood, or electricity. The boilers are possible to connect in parallel systems. The model used here is the THR 10-50. Geminox is also the manufacturer of the satellite units, model Modusat 75 in this case.
Address: BP1, F-29410 Saint-Thégonnec
Phone: +33 (0) 298794022 Fax: +33 (0) 298794757
e-mail: geminox@geminox.com

Radiator valves:
Caleffi www.caleffi.com
Caleffi manufactures and markets components for heating, air conditioning, plumbing, and anti-pollution systems. 
Phone: 0322 849265
e-mail: info@caleffi.it 

Heat meters:
KUNDO SystemTechnik GmbH www.kundo.de
Kundo is a German company that manufactures and markets energy regulation and monitoring components.
Address: Postfach 1332, D-78105 St. Georgen
Phone: +49 0 7724 93890 Fax: +49 0 7724 9389310