Case Study: Monza - Residenza Monte Pasubio

Short Description

The project is situated in a mixed residential urban location in a semi-central area of the municipality of Monza with a medium density housing.
The building type provides apartments of two or three rooms with habitable attics and basement, which houses cellars and box rooms.
It was allocated an area of private and common green spaces.
The building has short elevations facing north and south while the long elevations are directed towards the east and west.

The project is in climatic zone E (L. 10/91).

Climatic data of the intervention:
Monza (MI) 162 m asl 45 ° 35 latitude 9 ° 16' East longitude
Degree day of the intervention: 2404
External temperature of project: -5 ° C

Key Elements

Windows and Shading

The external windows will be of hemlock wood, with acoustic low-emissivity glass with a transmittance value of 1.74 W / m² K.

Heating and Hot Water

The central heating and domestic hot water (DHW) system have the following characteristics:

- Use of primary water accumulation of approximately 2600 litres  (multienergy cell) for release and removal of heat;

- Use of active solar thermal plant as a subsidiary source;

- Use of district heating using plate heat exchanger, supply by AGAM Monza;

- Climate control temperature;

- Satellite system with independent modules in individual homes for heating, DHW and cooling;

- Radiant floor;

- Remote management and remote reading of consumption in each dwelling via modem.

The unit consists of a terminal Modusat accumulation for the DHW with relative thermostatic mixer and a secondary circuit for heating.

A primary circuit connects the accumulation in thermal power modules satellite. Priority is given to heating the water from the sanitary accumulation, which has internally one exchanger, the heating circuit, complete with pump and mixing valve is placed in series. The primary circuit and heating circuit are separated by a hydraulic compensator.

The thermal energy transferred to each dwelling is counted by an integrator, sanitary water with a flow meter. Both devices are connected to the remote centralised telemetering system.

Cooling

The underfloor heating system in the project will also be used for summer cooling, that is, they will revert the energy produced by a refrigerated chiller. During the cooling, the chilled fluid reaches an appropriate temperature to a heat exchanger integrated to unit Modusat for subsequent mixing to ensure the most correct temperature value over the different environments and needs of the type of elements used. A diverter valve will switch for summer  and winter. The system appears to be four tubes with regard to the primary circuit (including housing and heating plant), two for heating and DHW and two for cooling, 2-pipe at the secondary circuit (in housing). Even the energy for cooling is accounted for by the system of centralized remote management and metering.

Solar Thermal

The solar cover meets more than 65% of energy needs for hot water in summer, combining a good supply of energy in the remaining months, which translates into annual savings of 2084 cubic meters of natural gas.

The solar array consists of 16 solar collectors facing south with an angle of 45 degrees.

The thermal storage capacity has been designed to provide 100 litres per square metre of solar array.

Solar Photovoltaic

It is planned to install a solar photovoltaic plant of 3.50 kWp to provide electricyt for the common parts of the building, plant that will enjoy the “Energy Bill” and exchange contracts in place. It was estimated that the energy produced can prevent the emission of 2.625 kg / year or so of CO2.

The photovoltaic modules will be placed in communal gardens at inclined at 20 ° in a south-west direction, while the remaining components of the plant (electrical panels and inverter) are installed inside the building.

The energy produced in excess of needs will be fed into the distribution network and valued in accordance with the current spot price.

The photovoltaic modules are created from 72 polycrystalline silicon solar cells with stable performance over time and high efficiency. The twenty modules will be divided into two strings of ten modules, with the isolated system in continous energy; the two strings will be connected in parallel, taking in a single inverter.

Project Management

Constructive solutions adopted meet standards of transmission and energy performance from Decree Law 311/2006 for the year 2010. Referring to the Lombardy regional legislation (Resolution Regional Committee 26 June 2007 - No. 8 / 5018) the building can be classified in class B, with an index of energy performance for winter air-conditioning (kWh / m² year) to 36.06 kWh / sqm per year.

Main Results

This project is the first building constructed by the cooperative where the issue of energy efficiency was given top priority, focusing mainly on system solutions.

Lessons learned

The intervention is not yet completed so it is not possible to make an assessment of the strengths and weknesses. There is, without doubt, a large saving from the point of view of heating costs.

Additional Information

The most interesting thing is that the heart of the heating system consists of a "thermal cell" which receives, either directly or through heat exchangers, the contributions made by the available energy sources. The stored heat is then disbursed to the various utilities in quantities and temperatures appropriate to the needs of the user. The thermal multienergy cell is an accumulation of primary fluid and works on the principle of natural stratification at different temperatures. Inside there are created three homogenous zones at different temperatures: low at the bottom, medium in the central area and high in the top part. The collection of energy is tapped directly to the primary fluid accumulated. Withdrawals and energy inputs are made to/from the area with most suitable temperature, in order to input energy with the maximum exchange efficiency, minimize disruption of the convection stratification and take the heat temperature closer to the needs of the user.