Via Cervignano, Milan
Refurbishment of an existing building: This project oversaw the energy requalification of a 107-apartment condo – from Class C to Class A
The upgrade from Energy Performance Certificate C to a level A wade made possible by equipping the building with thermal insulation and replacing the existing heating systems with a complete Clivet system based on multi-purpose heat pumps, high temperature water-water heat pumps, boilers and the Intelliplant comfort and energy management system.
The challenge for this building with eight above-floors and one basement floor with a total of 10,000m² was to improve the energy efficiency of the apartment building, reduce heating, air conditioning and hot water costs, and increase the building’s energy class. The existing distribution system was to be maintained.

Lessons learned
- By exploiting multifunctional technology combined with the high temperature heat pumps, it is possible to produce DHW above 65°C without using the boilers.
- Thanks to the management system implemented by Clivet Intelliplant it is possible to run boilers in combination with heat pumps, thus providing a perfectly reliable and efficient hybrid system for every eventuality.
Key facts
Building | Heat Pump and Source | ||
Location | Milan, Italy | Number of HP | 6 + 2 |
Construction | Early 2000s | Installed power | 6 x 80 kWh 2 x 100 kWh |
Heat distribution | radiators + fan coil radiators | Operation mode | bivalent, cascade |
Heated area | 10,000 m² | Heat source | air, water |
No. of apartments | 107 | ||
level of insulation | high thermal insulation | ||
Heating system | Domestic Hot Water | ||
Heat demand | – | DHW demand | – |
Type of system | central | Type of system | central |
Heating temperature | 65 °C | Max. temperature | 65 °C |
Circulation system | yes | ||
Other information | |||
additional heating | 6 x 200 kW boilers | COP | 6 x 3.23 2 x 6.46 |
Cooling | yes | Heating storage | 2 x 2000l tanks |
Cooling Storage | 3 x 2000l tanks | Heat pump models | Clivet WASN-XIN Clivet WSHH-LEE1 |
Refrigerant | R410A |
Description of the technical concept

The condominium was served by a centralized system based on three old gas boilers and radiators for heating and domestic hot water production and two large chillers with cooling towers installed on the roof, combined with fan coils.
To meet the challenge, interventions were made both on the building envelope, providing the condo with thermal insulation and replacing the old window with low-transmission windows; and on the heating and air-conditioning system, replacing the existing system with a complete hybrid system made by Clivet. The existing radiators, fancoils, and internal regulation and metering system were maintained.
The new installed system consists of:
- 6 ELFOEnergy Magnum WASN-XIN polyvalent heat pumps of 80kW, each capable of producing hot and chilled water simultaneously
- 6 boilers of 200 kW
- 2 ELFOEnergy Ground Medium WSHH-LEE1 100 kW high temperature water-to-water heat pumps
- 3 x 2000l storage tanks for summer cooling
- 2 x 2000l storage tanks for heating
- 2 x 2500l storage tanks for DHW, each equipped with two exchangers, which exchange respectively with the high temperature water-water HPs and the boilers, which only intervene in the event of greater demand
- 1 Clivet Intelliplant management system
The six multi-purpose HPs produce the hot water for the storage tanks, which act as a source to serve the high temperature HPs. During most of the year, when there is a similar demand for heating and cooling, hot and cool water can be produced simultaneously and hihgly efficiently.
DHW is produced by using the hot water of the mutlifuntional HPs, thus not using ‘outside’ water. Taking advantage of the multifunctional technology, combined with high temperature HPs, it is also possible to produce domestic hot water at temperatures above 65°C without using a boiler. The system is completed with six boilers which can work in integration in the case of high heating demands, or in total replacement in the case of heat pump maintenance.
The entire AC-system is managed by the Clivet Intelliplant supervision system, which coordinates the entire thermo-cooling plant, enabling the central resources according to the requests received from the individual flats and always activating the most efficient resource (while favoring the use of heat pumps). Due to this system it is possible to run heat pumps in combination with boilers, thus providing a perfectly reliable and efficient hybrid system for every eventuality. It allows the consumer to monitor thermal, cooling and electrival consumption.
Pictures: Via Cervignano (Milano-Italy) Clivet S.p.A.
IT005 Via Cervignano