VENTUS Air Handling Unit for a Historic Hotel in Budapest, HU

In a technical case study, we often look for an exceptional challenge, an unexpected turn of events or a distinctive engineering solution. In the Kígyó Street hotel development, however, the value of the story lies elsewhere: in the transformation of a city-centre building more than 160 years old, whose modern ventilation is provided by a VTS VENTUS modular air handling unit with an airflow capacity of 10,000 m³/h.

When reporting on an impressive reference project, we almost automatically look for the story: what was the greatest challenge, what unexpected problem had to be solved, and where was a special technical intervention required?

For this project, the answer was surprisingly brief:

• the unit was specified in the design;
• VTS delivered it;
• it was installed.

At first, this may seem like a project with no story to tell. But there is a story—and the building itself provides it.

A new role for a building dating back to 1862

Located at the corner of Kígyó Street and Váci Street, the building originally known as the Várady House was built in 1862. Following a long period of vacancy, the building of heritage significance is being redeveloped into a four-star hotel with 100 rooms.

Behind the historic façade, a seven-storey hotel covering approximately 4,400 square metres is being developed, or has already been completed, with a glass-roofed atrium, new rooftop floors and modern building services infrastructure.

In a city-centre refurbishment of this kind, the building services must accommodate the existing building’s characteristics, the available space and the requirements of hotel operations, while also meeting energy efficiency and operational expectations.

For this project, VTS Hungary supplied a VENTUS VVS modular air handling unit with an airflow capacity of 10,000 m³/h and a run-around coil heat recovery system.

A solution configured for the building

One of the key features of VENTUS VVS is its modular design. The unit is not limited to a fixed, predefined arrangement: its individual functions and technical parameters can be tailored to the ventilation system of the particular building.

The air handling unit can be configured with several heat recovery options:

• a rotary heat exchanger;
• a counterflow hexagonal plate heat exchanger;
• a crossflow plate heat exchanger;
• a glycol-based run-around coil system.

The choice of technology depends on factors including energy performance targets, the available space for building services equipment, and the requirements for separating the supply and extract air streams.

The maximum heat recovery efficiency of the VENTUS VVS range can reach 92%. This maximum does not apply to every unit configuration. The actual value is always determined by the specific unit’s configuration and selection data. The Kígyó Street system operates at an efficiency of 74%.

Energy-efficient operation with monitoring and control

The advanced automation of VENTUS VVS air handling units can support energy-efficient operation based on measured air quality parameters. The control system is built around a uPC3 controller, while the factory-provided visualisation and remote HMI interface enable the unit’s operation to be monitored and controlled.

Energy-efficient EC motors with an IE4 efficiency rating are also available for VENTUS VVS units with airflow capacities of up to 3,000 m³/h.

Technical design is supported by the ClimaCAD Online selection software. In addition to technical documentation for the selected configuration, the software can generate Revit objects and 2D and 3D DWG files. This makes it easier to integrate the air handling unit accurately into the building’s design and BIM workflows.

A durable casing and easier maintenance

The unit’s casing consists of polyurethane-insulated sheet metal panels with an AZ150 Aluzinc coating and an internal metal profile structure. The rigid, weather-resistant casing, thermal breaks and inspection doors with labyrinth seals help ensure adequate airtightness and reduce the risk of condensation.

A separate roof system is available for outdoor installation, while the design of the module connections provides enhanced airtightness.

The air handling units can be fitted with various pre-filters and final filters. The guide-rail filter arrangement allows faster, simpler replacement. As a general recommendation, two to four filter changes per year may be appropriate. However, the actual frequency must always be determined by the dust load in the surrounding environment, the unit’s operating hours and the differential pressure measured across the filters.

When smooth delivery is what creates value

The Kígyó Street project required no dramatic crisis management or last-minute technical intervention. The appropriate unit was designed, selected, delivered on time and installed.

In a well-prepared development, this is precisely the supplier’s role.

The value of VENTUS VVS lies in its ability, when configured to the building’s requirements, to support the hotel’s ventilation through energy-efficient operation that can be monitored and controlled.