A model of urban regeneration and architectural sustainability

Merlata Bloom Milano is the futuristic ‘lifestyle centre’ located in the north-west of Milan, which opened on 15 November 2023. The centre acts as a spatial and functional ‘hinge’ between the UpTown residential district of Cascina Merlata and the MIND innovation district.

The complex spans 70,000 m² of GLA, set within a 30-hectare park. 
With over 210 shops, 45 Food & Beverage venues and 10,000 m² dedicated to entertainment and culture, it is currently Milan’s largest shopping centre. 

The architecture, designed by CallisonRTKL, is characterised by a monumental 8,500-square-metre glass dome and the use of 4,500 cubic metres of laminated timber, elements that evoke the concept of ‘blooming’ and integration with nature.

Merlata Bloom Milano inteno centro giardino Merlata Bloom Milano interno centro

The challenge

The main objective of the project was to create a space of high social value that is comfortable and sustainable, both environmentally and in terms of energy consumption. The challenge was to integrate 150 shops, a 20,000 m² Sky Garden, 10,000 m² of cultural and cinema spaces, and five Food & Beverage zones into a single structure meeting high standards of modern urban planning, biodiversity and sustainability, whilst ensuring minimal environmental impact despite the project’s scale.

The practical objectives included: 
Comfort and Wellbeing: Ensuring an optimal microclimate for over 3.6 million potential users, whilst reducing the environmental impact.
Decarbonisation: Creating a completely gas-free building.
International Certifications: Achieving the highest levels of BREEAM certification.

The Key Players

Client: Merlata Mall S.p.A. (Ceetrus, ImmobiliarEuropea, SAL Service).
Management and Leasing: Nhood Services Italy.
Architectural Design: CallisonRTKL.
MEP Designer: RETHINK ENERGY 
Air Conditioning Installer: Ditta Ganni Benvenuto 
HVAC Supplier: Clivet.

In addition to the rooftop units described above, there are two stand-alone heat pump air conditioning units using eco-friendly R32 refrigerant, of the CSRN-Y rooftop type, featuring REHVO thermodynamic recovery, free cooling and electronic filtration, serving one of the large single-brand retail spaces.

The Solution

From the perspective of indoor comfort systems, a technologically advanced air conditioning system based on heat pumps and renewable sources was chosen to meet the challenges, avoiding the use of fossil fuels.

Air conditioning and air treatment for the food court and bridge/connector are provided by five Clivet CRH-XHE2 rooftop units connected to a WLHP water loop system, where maximum temperature control is managed by closed-circuit evaporative cooling towers and groundwater, whilst minimum temperature control is managed by the district heating network. 
The indoor units for air conditioning in restaurants, shops and medium-sized retail spaces are also connected to the WLHP. Specifically, these comprise over 60 autonomous direct expansion reversible heat pump air conditioning units for water loops (EVH X SPACE, EVH-X, CRH, WSHN-XEE, WSHN-EE) which ensure comfort in numerous outlets within the Fashion Court and Food Court, combining high energy efficiency with compactness and ease of installation and maintenance.

Air quality in various shops within the shopping centre is managed by 23 ZEPHIR3 heat pump air renewal and purification monobloc systems featuring inverter technology and active thermodynamic recovery.

The shopping centre and the Winter Garden are served by 15 packaged CLIVETPACK2 CSRN-XHE2 air-to-air air conditioning rooftop units designed for medium-occupancy applications. These units heat, cool, dehumidify and purify the supply air, balancing the exhaust air flow to ensure the comfort of visitors and staff. Equipped with a dual refrigeration circuit featuring modular scroll compressors for continuous capacity adjustment to actual energy demand and thermodynamic recovery—to recover energy from the exhaust air—they enable a reduction of up to 50% in primary energy consumption compared to traditional systems.
These rooftop units are also fitted with a water coil to utilise heat from the district heating network during the heating season.

As well as heating, the domestic hot water supply for bathrooms, shopping centres and restaurants is connected to the Milan West district heating network. 

The multiplex cinema is served by 10 packaged air-cooled heat pump units designed for high-occupancy areas, ensuring clean air and comfort in the cinema auditoriums, and 1 packaged rooftop unit (CSNX-XHE2) for medium-occupancy areas, alongside a rooftop unit (CSRN-XHE2) for high-occupancy areas serving the foyer.

5,000 square metres of photovoltaic panels cover approximately 20% of the building’s total electricity requirements.

Merlata Bloom Milano Rooftop clivet sul tetto Merlata Bloom Milano particolare di unita Clivet sul tetto e canali

Units Installed

  • 50 Versatemp EVH-X SPACE water-loop units
  • 2 Versatemp EVH-X water-loop units
  • 4 CRH rooftop-type water-loop units
  • 3 WSHN-XEE2 hydronic heat pumps
  • 2 R32 CSRN-Y outdoor air-cooled heat pumps
  • 24 CSRN-XHE2 rooftop-type standalone air-to-air air conditioning units for medium-occupancy applications
  • 10 CSNX-XHE2 rooftop-type standalone air-to-air air conditioning units for high-occupancy applications
  • 23 ZEPHIR3 CPAN-XHE3 monobloc units

Results

The adoption of advanced plant engineering solutions, in particular the WLHP system and decentralised systems, has enabled the achievement of excellence in terms of energy efficiency, environmental performance and cost-effectiveness, whilst simultaneously improving the overall comfort of the spaces.

Energy efficiency and environmental sustainability
Energy consumption is 24% lower than European nZEB standards, with primary energy savings of up to 35% compared to traditional systems. Climate-changing emissions have been significantly reduced, with an estimated saving of around 9,400 tonnes of CO₂ between now and 2050.
Over 5,000 m² of photovoltaic panels contribute to the production of clean energy, covering around 20% of the building’s total electricity requirements.

Reduction in investment and operating costs
The ease of installing the heat pumps and the sharing of the initial investment among the individual shop owners have proved to be a winning strategy. Operating costs have also been reduced thanks to the decentralisation of the systems, which has made it possible to eliminate pumping costs and activate air conditioning only where and when it is actually needed.
The WLHP system’s water circuit transfers energy between areas with opposing thermal requirements, increasing the overall efficiency of the system.

Comfort, control and air quality
Each individual area or shop is able to automatically set and maintain its own ideal climate throughout the year, regardless of location, size or intended use. This ensures a high level of comfort and improved air quality, helping to make the building not just a shopping centre, but a true hub of social interaction and sustainability.

Flexibility and dynamic space management
The principle of decentralisation, applied to both rooftop solutions and high-traffic areas such as restaurants and retail spaces, ensures maximum flexibility in the use of spaces. The modular and ‘plug & play’ nature of the units allows spaces to be quickly consolidated, adapting them to tenants’ needs without altering the main plant backbone.
This versatility facilitates tenant turnover and ensures that every new configuration meets the high standards of comfort and energy efficiency.

Certifications
The project has achieved BREEAM New Construction certification with a ‘Very Good’ rating and BREEAM In-Use certification with an ‘Excellent’ rating, confirming the quality of the design choices and the building’s overall performance.

merlata Bloom Milano_rooftop clivet sul tetto particolare merlata Bloom Milano unita Clivet sul tetto