Old-world charm – latest HVRF technology: Generator Hostel Amsterdam

A budget design hostel with first-class air conditioning

The Generator Hostel in Amsterdam accommodates 564 guests in 168 twin and quadruple rooms plus a luxury apartment. Its unusual architecture is not its only impressive feature; it also boasts BREEAM certification with the quality seal for sustainable building. One of the key contributory factors to this award is its Hybrid VRF air conditioning system.

The requirements:

Dating from the year 1916, the building was formerly part of the University of Amsterdam. As part of the conversion into a design hostel, two glassed-in floors were added to the building. To retain the connection with the building's former incarnation, countless rooms have been furnished with elements in keeping with the original edifice. This is in complete contrast to the air conditioning system. To achieve the ultimate in comfort and a peaceful, homely atmosphere, the developer was keen to use modern technology.

The solution:

A total of 14 Hybrid VRF R2 outdoor units have been installed on the roof of the Generator Hostel. Next to these are two outdoor units that supply the heat register of the central ventilation system.

All the guest rooms have their own ceiling concealed unit, with which the temperature can be set to suit the guests' requirements via a permanently installed cable remote control. Each individual indoor unit can be operated independently in heating and cooling mode. Heat that is removed from the rooms being cooled is used to heat those rooms where warmth is required. The high degree of heat recovery, in which energy is not discharged unused into the environment but is "relocated" in the building, is a key factor in the certification of the building by BREEAM and the award of the quality seal for sustainable building following its redesign.

HVRF technology in house: Mitsubishi Electric, Ratingen

The headquarter for innovation

For over 90 years, the Mitsubishi Electric Corporation has been supplying top-quality products in a wide range of technical fields to customers all over the world. When construction of the company's new headquarter in Germany commenced, one thing was clear: the technical infrastructure should be provided as far as possible by the company itself – along with the air conditioning.

The requirements:

The new German headquarter in Ratingen‑East, located on five‑and‑a‑half floors and with 16,000 m2 of office, training and display space, offers plenty of room for an ultra-modern office and communications landscape. It is designed to accommodate up to 750 employees. In the design and execution of the new building, Mitsubishi Electric placed great emphasis on a good energy balance and the sparing use of resources. The declared aim was to cover the entire heating and cooling energy requirement on the basis of renewable energy sources with the air conditioning technology used.

The solution:

Mitsubishi Electric decided back in the design phase on a VRF R2 system for simultaneous heating and cooling with heat recovery, along with many other technologies developed by the company. In this system, the thermal energy conducted away from a room that is being cooled is supplied to another room with a heat requirement. If no heat is required, this thermal energy can be used alternatively to produce hot water.

An HVRF system is being used to air condition the training centre. Based on R2 technology, it combines the benefits of a direct evaporation unit with those of a water-based system. In many applications the use of R2 technology leads to up to 40% lower energy consumption and up to 25% lower investment costs than with comparable chilled water systems. Additional energy-saving potential is provided by the full integration of the air conditioning system into the multifunctional TG‑2000A operating software.

The technology calls the tune: HVRF system at Radio 7 Ulm

Innovative and energy-efficient on air

Radio 7 is one of the three big regional stations in Baden-Württemberg. The station's live and recording studios are air conditioned, a task previously performed by the central ventilation system with a heat register supplied by a classic chiller unit. Now Hybrid VRF technology from Mitsubishi Electric offers greater comfort using less energy.

The requirements:

The radio station's new air conditioning system had to satisfy three conditions. First, it should require less energy than standard systems for the same output. Second, it should offer users a high comfort level, primarily through individual temperature control in each studio. Third, rooms used by people should remain free of refrigerant. Another special circumstance was that the old air conditioning unit was operated using R22 refrigerant. Due to the prohibition on this, necessary repairs and servicing could no longer be carried out, and so a replacement was required.

The solution:

Radio 7 is now using a Hybrid VRF system. The unique technology combines the benefits of a direct evaporation unit with those of a water-based system. A special refrigerant distributor, the Hybrid BC Controller, transfers the energy from the refrigerant to water as a transport medium. The indoor units, eight ceiling concealed units in this case, operate with special water coils.

The PURY‑EP200YLM outdoor unit installed in the boiler room with 22.4 kW of cooling capacity and 25.0 kW of heating capacity offers an impressively high degree of efficiency. The air intake is via a decommissioned chimney, while air is blown out through a newly installed air duct. Each ceiling concealed unit can be operated independently in heating and cooling mode. Adjustment is via a PAR‑31MAA cable remote controller in each case.

Heating or cooling with the Y series: Design Offices in Dusseldorf

Modular air conditioning system for optimum work flow

In so-called „working worlds of tomorrow“ –, Design Offices in nine German cities offer flexible office, meeting and event spaces with a refined ambience for hire. To match the professional technical fittings of the Design Offices, the Dusseldorf premises were to be provided with equally innovative air conditioning technology.

The requirements:

Everyone has a different idea of what constitutes a comfortable climate – even at work. In view of the frequently changing users of the rooms at the Design Office Dusseldorf, it was particularly important to facilitate an individual control strategy. On the one hand, it had to be possible to account for room use on an individual basis, while another challenge was posed by the staged renovation and completion of the building complex. As well as these requirements, the developer and designer wanted an air conditioning system that would keep energy consumption down.

The solution:

with the City Multi Y series, the Design Offices are investing in air conditioning technology that takes full account of all the requirements. 34 indoor units are supplied by powerful outdoor units for optional heating or cooling.

The building complex was fitted out with the new technology on a modular basis following the completion of individual phases of the building. By dividing the air conditioning system into autonomous sections, one outdoor unit can operate in cooling mode while another unit is still in heating mode.

As a higher-level control strategy, the heating or cooling function is selected automatically via a temperature sensor with a predetermined setpoint. Single cost calculations can be produced for the leased units via the central controller GB‑50 ADA in conjunction with the system software TG‑2000A.

Economical replacement technology: Deutsches Zahnärztliches Rechenzentrum (German Dental Datacentre) in Stuttgart (DZR)

New for old without changing pipes

Technical and legal requirements are forever changing. This applies in particular to refrigerants. Thus current legislation prohibits the use of the non-environmentally-friendly refrigerant R22 after 2020. Instead of decommissioning obsolete air conditioning systems in extreme cases, they can also be modernised, as in the example of the German Dental Datacentre (DZR) in Stuttgart.

The requirements:

As the obsolete R22 air conditioning system of DZR Stuttgart increasingly experienced malfunctions over the years and had to be repaired more and more frequently, the existing products were to be replaced both due to economic considerations and for reasons of age. Instead of patching the system up and thereby running a significant safety risk, DZR Stuttgart looked for a modern, sustainable technology that would also cover a higher cooling capacity. In the ideal scenario, the modernisation was to take place while the data centre continued to operate.

The solution:

Mitsubishi Electric's Replace technology is ideally suited as a replacement for an VRF R22 system; only the old units had to be exchanged. The old pipe system remains in the building. Another plus factor is the significantly greater energy efficiency.

In DZR Stuttgart the exchange of outdoor units was completed within just two-and-a-half hours. Thanks to good planning, a new outdoor unit is transported up to the roof and an old unit removed in exchange.

Four VRF Replace outdoor units in different capacity sizes now supply new exchange indoor units with a cooling and heating function. Beyond the exchange of units, some new components have been added to the air conditioning system; whereas the installed cooling capacity was 56 kW previously, a capacity of 106 kW can now be covered by the new units.

An inviting modern ambience with R2 technology: Prizeotel in Hamburg

Saving operating costs with heat recovery

New buildings with exciting accommodation concepts are emerging everywhere. One example of this is the Prizeotel, which combines designer ambience with the charm of a private hotel at budget accommodation prices. Any developer succeeding in overcoming so many challenges will be no less discerning when it comes to air conditioning, and R2 technology was the perfect answer.

The requirements:

The first Prizeotel opened in Bremen back in 2009. The second followed in Hamburg in June 2014. For the group of owners, it was especially important to combine comfort with economy. The priority was to tie ongoing running costs into the overall economic concept and keep them permanently low. Following the initial experience of a classic chiller-based air conditioning system for air conditioning the Bremen Prizeotel, the investor wanted to take the Hamburg project a stage further.

The solution:

The installation of an R2 air conditioning system with water-cooled direct evaporation units enables the Prizeotel to heat the hotel rooms using thermal energy drawn from rooms that require cooling, such as the dining room. If no heat requirement should exist in the hotel rooms, the energy can be used to produce hot water via three buffer tanks with a capacity of 2,000 litres.

17 compressor units in all deliver a cooling capacity of 290 kW. The BC Controllers are accommodated in the service and equipment rooms. The ceiling concealed units in the rooms have a cooling capacity of 1.7 kW and heat output of 1.9 kW to meet demand.

With two AG‑150 control units, six expansion controllers and input modules for the outside temperature, each unit can be operated centrally. Remote monitoring and servicing is also possible.

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