A rebirth of an icon

Set in exclusive Mayfair in the heart of London, the May Fair Hotel has been playing host to the rich and famous since its historic opening by His Majesty King George V in 1927. Acquired in 2003 by the Radisson Edwardian Group, this prestigious 5 - star hotel has undergone a comprehensive, £75million plus, refurbishment and extension, which was completed in the autumn of 2006.

The May Fair’s redesign includes a luxurious 201 seat private cinema/theatre, three highly impressive function rooms, the stylish May Fair bar, the superb Amba Bar and Grill and the stunning May Fair Spa. In addition the hotel has over 400 bedrooms including no fewer than 9 signature suites and a magnificent 2-bedroom penthouse apartment.

Space Air’s relationship with the Radisson Edwardian Group spans almost 20 years and for over 8 years the company has been an essential player in hotel group’s strategic development programme. Space Air was closely involved with an established design and installation team, comprising architects, M&E consultants, builders, interior designers, equipment installers and specialist equipment suppliers.

Although Space Air, as a Daikin distributor, does not offer an installation service, they were to have comprehensive input into the complex system design, produce full schematic drawings, provide project management advice, conduct commissioning and deliver staff training prior to hand-over.

Early Considerations

The requirement was that full air conditioning – heating, cooling and ventilation would be provided to all public areas, all bedrooms and corridors, all occupied staff areas, all affiliated premises including shops, cafes and the Palm Beach Casino.

The air conditioning systems were to be of modular concept to enable phased installation. Completed areas would be immediately re-occupied and it would not be possible to have ongoing works in these areas. Existing building refurbishments of this complexity and stature inevitably involve progress revisions and unforeseen challenges therefore the air conditioning systems selected would need to be flexible in application.

From the outset, low noise levels were a priority. Energy efficiency was also vital, not only from an operational viewpoint but also because electrical power supplies are at a premium in London. Finally the air conditioning installations were required to be fully compliant with current regulation.

The project

The original building configuration was a ‘U’ shape, and comprised sub-basement and basement function suites, basement service and back-of-house facilities, a ground floor reception, theatre, bar and restaurant, guest accommodation over seven floors, plus separately leased, casino, shops and cafés.

An extra floor would extend the existing hotel and the open side of the building would be the location for a new 8-storey wing providing an additional 100 bedrooms. A 9th floor would be added to the front elevation of the hotel to create a fabulous penthouse suite – the second largest and one of the most luxurious and expensive in London.

The initial plan was to refurbish each floor in four zones, including the new wing, allocating one Daikin VRV condensing unit per zone on each floor. As far as possible, one floor or zone was to be left empty between site work and paying guests to minimise disruption and disturbance. As the air conditioning to each zone was completed it would be connected to Daikin’s I-Manager control system, commissioned and hotel staff trained in its operation by Space Air technicians, prior to handing over for occupation.

Work commences Spring 2004

An early difficulty was the siting of a fixed crane to facilitate lifting requirements for the entire project. The readily available sites involved the crane’s counterweight over-flying adjacent offices and this was not permitted for insurance reasons. The only solution was to site the crane in the central core; however this entailed the, previously unplanned, demolition of the existing basement and sub-basement function rooms!

The first design challenge for Space Air was to ensure that the cooling, heating and ventilation requirements of the larger public areas could be satisfied without any need to access ceiling voids for routine maintenance purposes. To facilitate this Space Air designed bespoke air handling units, combining large (FXMQ) Daikin Ducted fan coil units and Daikin’s VAM heat recovery ventilation modules.

These roof-mounted, fully weatherproofed units were prefabricated at Space Air’s Guildford factory. The units ensured that the mix of fresh air and return air did not exceed 1ºC over set-point and the Daikin I-Manager controls would hold off operation of the VAM section until the room set-point was reached and maintain the 7-8°K room/ambient differential. In total, 21 of these special units were manufactured, serving all major public areas and function suites.

To minimise future maintenance disturbance in the guest rooms and to reduce the number of ceiling access points to avoid spoiling the aesthetics, much of the air conditioning equipment was located outside the rooms – the obvious exceptions being the fan coil unit, its controller and sensor.

The VRV systems’ heat/cool branch selectors or BSVQ boxes were all neatly fed from headers and aligned with their own power supplies and identification, at dedicated corridor locations in each zone. The positioning of these areas was critical to ensure that maximum recommended refrigerant pipe lengths were within design parameters.

Most of the VRV Condensing units were positioned on the roof and surrounded by acoustic louvre screening. Part of the original A/C plant was an old air-cooled chiller serving the Casino; this was replaced by a new Daikin 500kW EWAP, screw compressor, air-cooled chiller. To minimise client disruption, the chiller changeover took place in a four-hour operation, while the casino was closed.

Although one of the quietest chillers of its type, this installation needed to comply with stringent noise restrictions set by Westminster City Council and cause no disturbance to those occupying the penthouse suite a few metres away. The chiller was acoustically enclosed by Conebeare. The resultant sound reduction is astounding and the only indication the chiller is operating, even at very close quarters, is the run light on the controller.

During the early phases, refurbishment of guest rooms at first floor level was undertaken. All went well until soil pipes from the toilets were to be connected to the main SVP. The construction team discovered that the old cast iron pipe work was very brittle, and it collapsed. The major consequence was that all of the guest rooms connected to this single riser were suddenly out of action. If this were to be repeated the hotel would have to close, so an urgent re-think was required. It was decided to rezone and re-phase all works, including the air conditioning. The final solution was to increase the number of zones from 4 to 7 and work vertically rather than floor by floor.

Inevitably, many difficulties were experienced throughout the project; noise, workmen and dust were all issues, which the hotel management dealt with as best they could. However the greatest ongoing difficulties were the constantly changing requirements as the project evolved. The refurbishment of any existing building will bring many structural idiosyncrasies to light which are only apparent after extensive strip out works, slight level changes, beam sizes and construction methods to mention a few.

The finishing touches

The first area to be finished was the May Fair bar. Here the supply air enters the space via linear slot and decorative spiral grilles, which coordinate well with the semi-circular bar. The return air linear grilles are discreetly positioned above the perimeter seating, mounted vertically in the feature ceiling.

The Amba Bar & Grill presented a unique problem as an interior design revision included exposing the kitchen. Return air grilles, already installed, were close to a wall, which would now be removed to expose the kitchen. It was determined that warm air from the kitchen could be drawn into the return air creating a control problem. This was overcome by using a glass panel suspended from the new servery. An extract hood, with inverter-controlled fan, provided a slight negative air pressure within the kitchen this ensured no cooking smells filtered into the restaurant.

An EUWAB24KZ (55kW) Daikin air-cooled chiller, serving a cooling coil in the fresh air intake, cooled the entire hotel kitchen supply air system.

The newly constructed 201 seat private cinema/theatre also posed some difficulties as an extensive stage lighting arrangement blocked the planned route for air conditioning ductwork. This was quickly resolved and the theatre has proved to be a comfortable venue for a number of Premier film screenings. The projection rooms are air-conditioned using Daikin 4 way blow ceiling cassettes.

Daikin 600 x 600 ceiling cassettes are also employed in all the opulent public access toilet areas.

Guest Rooms

Standard guest rooms are air-conditioned using concealed ceiling units, conventionally mounted into bulkheads. However, some signature suites presented a different challenge as floor level changes and existing beams prevented the use of ducted units in the lounge areas. In these cases, ceiling cassette units were employed. For the lower level bedrooms, again concealed ceiling units were used.

The ceiling height in the penthouse suite was lower than originally designed due to planning restrictions on the overall height of the hotel; this required a more innovative solution. Daikin Chassis type VRV floor mounted fan coil units were concealed in partition walls, the interior designer selected purpose made linear grilles to create a feature. The fresh air was supplied by two roof mounted Daikin VKMG units, weatherproofed by Space Air. These heat recovery ventilation units with integral cooling coils were required, as the penthouse can be used as an occasional meeting room for up to 30 people.

The Function Rooms

The first floor conference area and business centre comprising 13 meeting rooms and 2 reception spaces, is capable of accommodating between 6 and 120 people. Here, because of restricted slab heights and existing beams, ceiling cassette units were used in conjunction with VAM heat recovery ventilation units.

The basement ‘Crystal room’, one of the major function rooms, features the largest Baccarat chandelier in Europe, (7 metres across). This single chandelier represented an extra 9kW load and because of its size and fixing requirements meant that planned services had to be re-routed around it.

The Atrium was a completely new first floor structure with a curved glass roof. This space represented a large air conditioning load with no obvious locations for fan coil units. The solution here was to install Space Air purpose built roof mounted air handling units, as used in other public areas, supplying conditioned air via 28 nozzles. Two further function rooms were constructed, including the spectacular mirror walled, Danziger room which seats 200 people.

Finally the May Fair Spa, described as ‘decadent luxury brought stunningly up to date’, features a swimming pool, gymnasium and 8 treatment rooms. The reception area incorporates a spectacular relief mural with cascading water. In the majority of these areas, ceiling cassettes were used for ease of maintenance.

The whole site is controlled by Daikin’s state-of-the-art integrated building control system (Intelligent-Manager), providing comprehensive remote system control and monitoring facilities which maximises operational efficiency and enables rapid response to any fault alarms or necessary adjustments. It provides the platform for a planned maintenance system and monitoring of the electrical consumption of the entire air conditioning and ventilation installation.

The Daikin VRV system’s, modular concept, enabled the project to proceed in phases whilst large areas of the hotel remained in operation. One of the most flexible, energy-efficient and cost-effective systems on the market today, VRV is particularly suited to hotel applications. Weekly site attendance by experienced Daikin system design/applications and commissioning engineers from Space Air assisted in achieving rapid and effective solutions to various difficulties presented during the refurbishment programme.

The Radisson Edwardian Group is reported to be delighted with Space Air’s service and technical support, which assisted the programme to remain on track, minimising disruption and helping to ensure the May Fair’s position as one of London’s finest hotels.

Equipment statistics

In all Space Air was responsible for supplying: 62 REYQ-M VRV systems (69 outdoor units), 2 RXSYQ-M VRV systems, 1 x 500kW and 1 x 55kW air-cooled chillers – in total equivalent to 3.4 MW of cooling capacity. 669 Fan coil units – 8 different designs were incorporated into the project. 81 VAM Heat Recovery Ventilation units – equivalent to a total of 28.46m3/s of fresh air were installed. A further 2017 ancillary components and one I-Manager control system completed the equipment list.

All of this represented 157 deliveries to site, 88 days commissioning and staff training and 77.1 tonnes or 468m3 of equipment, for one of the largest and most prestigious projects of its type in the UK.

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