Architect's Benson & Forsyth were selected by the client following a design competition and Oscar Faber (now FaberMaunsell) was appointed to design mechanical and electrical services, lifts, security and IT infrastructure.
The new Millennium Wing covers an area of 4500 m2 and interconnects with the existing gallery. It incorporates two new galleries, one at ground floor level (750 m2) housing a permanent display of Irish art, and a gallery for visiting exhibitions on the first floor (1000 m2). Ancillary areas include audio-visual rooms, a multimedia area and dedicated study areas for research, as well as an archive. There is also a collection handling area for receiving art work before it is exhibited.
The public enter the gallery via the 'Cube' lobby at the main entrance which brings them into the orientation court, measuring some 20 m high by 10 m wide. As well as allowing access to the galleries, this connects with the winter garden restaurant, bookshop and ground floor servery.
"Our brief was to provide comprehensive m&e services for all of the exhibition spaces and public and private ancillary areas," explains FaberMaunsell's Stuart Bailey. "We maintain close control of conditions in the galleries and collection handling area, with a set point temperature of 19°C in the winter, 24°C in the summer and 55% ±5% rh all year round. Lighting also has to be carefully controlled to avoid artwork being exposed to excessive levels of uv and direct light"
Mechanical services
Most of the temperature control in the building is achieved by an all-air system using two air-handling units, one serving the close control areas and the other serving the general areas.
"Both of the air-handling units incorporate fans, filtration, heating coils and cooling coils and main humidification, and are located in the basement plant room," notes Bailey. "In addition, the air-handling unit serving the galleries and collection handling areas incorporates an additional high-grade filtration stage."
Variations in humidity in zones served by the gallery air-handling unit are compensated by steam humidifiers installed in ducts leading to specific areas.
To accommodate the variation in heating required at different times of the year, modulating sectional boilers were selected to allow staging of heating loads as necessary. Apart from providing the heating element to the air-handling units, the hot water is utilised for an underfloor heating system laid beneath the limestone floor in the orientation court and winter garden where the heating load could not have been handled solely by treated air.
As there is always a necessity to have heating available to maintain close control conditions throughout the year, it was also decided to utilise hot water to local wcs and pre-heating of water for the dishwashers and other appliances in the kitchen. "We made a conscious decision with the client to maximise the use of the available hot water to reduce the energy costs associated with the everyday high electrical consumption for dishwasher water heaters," recalls Bailey. Instantaneous hot water heaters provide hot water to other wcs and areas further away from the boiler area as distribution losses from the central hot water system would have been excessive.
Monitoring of conditions in the galleries is achieved with a series of temperature sensors at strategic locations throughout the space. Because of the variable occupancy and continual opening and closing of doors, dynamic control has been avoided. Instead, a band of tolerance has been established via the building management system (bms) and the system will respond only to extended variations outside this band.
The controls system is connected via a number of outstations installed at motor control centres through to the bms central unit located in the gallery's main security area. "The client wanted the bms system to provide as much information particularly in relation to the temperature and humidity levels in the galleries and also the systems directly associated with the areas," explains Bailey. "We also incorporated check-meters on the hot water and electrical services serving the areas under the catering concession allowing the client to record consumption and print out usage for billing if necessary."
The bms also enables the close control and occupancy hours to be monitored and controlled for energy management. Other features adding to the efficiency of the systems are the use of heat recovery via return air and the inclusion of inverter control on all main fans and pumps.
Electrical services
The existing 1000 kVA transformer had insufficient capacity to supply the existing gallery and the new wing, so a new 1600 kVA transformer was installed to serve both buildings. The supply from the transformer feeds a new splitter switchboard providing mains distribution through to both the old and new wing. The new main switchboard serving the Millennium wing is located in the basement of the building adjacent to the main central plant areas.
Sub-distribution from the main switchboard emanates via strategically located risers through to distribution boards for general lighting and power installed in cupboards at each floor level. Dedicated services are also provided directly to the mechanical plant and control centres, security services such as cctv and access control and also emergency lighting.
Both natural and artificial lighting play a prominent part in the overall impression of the finished building.
The first floor gallery, orientation court and winter garden receive natural daylight through roof lights and in the gallery it was necessary to ensure that excessive levels of ultra violet light would not damage the exhibits. "We carried out daylight modelling analysis looking at the angle of the sun for different times of year to simulate lighting levels which could be expected," Bailey explains. "This enabled us to confirm that the roof lights were angled to maximise the amount of daylight entering the first floor gallery while not exceeding the maximum permitted 200 lux at the picture face."
To provide control of natural daylight entering the gallery areas, each rooflight is provided with adjustable louvres controlled manually by gallery staff. "The client had heard bad things about automatic louvre control so we opted for the manual system, using photocells feeding information to a central pc so that staff can make informed decisions based on these readings," Bailey notes.
In the ground floor gallery, the only daylight entering the space is through a large window at the front of the building. In both galleries, the artificial lighting used to supplement daylight is mainly based on track mounted low voltage spotlights with ultraviolet filters and sculpture lenses to provide an element of framing. In the both galleries, the tracks are mounted above 'floating' walls that are used to divide the space into bays. Each spotlight is aimed across the bay to the exhibits on the opposite wall to provide a good spread of light. Lighting from above would have created too much shadow.
Additional ambient lighting is provided by fluorescent uplighters on the tracks, making effective use of reflected light via the light surfaces of the natural finished plaster, beech flooring and limestone borders. In other public and staff areas, recessed compact fluorescent downlighters have been installed. Unusually, the architect used the same fittings for 'back of house' areas as for public areas.
In addition, the high ceiling areas of the orientation court and winter garden use a combination of metal halide downlighters and floodlights to provide the extra light output needed to achieve designed illuminance at ground level. Exterior lighting is minimal, using buried uplighters to provide some subtle illumination of the facade with dedicated lighting for the entrance banner.
All of the public area lighting is linked to a lighting control system with scene setting functionality so that staff can set different scenes to accommodate the varying daylight levels. Emergency lighting for escape purposes is linked to a central battery system.
Although most of the exhibits at the gallery will be traditional in nature, the gallery is taking a high-tech approach to its presentation of them. Plasma display monitors are used to convey information to visitors and the audio-visual and multimedia areas are used to provide additional information in a variety of formats.
All of these factors combine to demand a high level of flexibility from power and data services and this is achieved by the use of strategically placed wiring routes, recessed into the floors, with regularly spaced outlets for power and data covered by brushed stainless steel grommets. In the multimedia area and bookshop, bespoke furniture has been supplied with integrated dado trunking for connection of IT equipment and electronic point of sale cash registers. The entire IT infrastructure, incorporating data and telephony, is linked back to a main server in the old building. To increase the speed of data transfer, a fibre optic cable has been installed to connect the two systems.
Apart from conventional smoke detection in non-public areas, FaberMaunsell was faced with another challenge in positioning the smoke detectors in galleries and other public areas. "We opted for an aspirated air system with sampling pipes positioned strategically in the spaces. These sample the air for different levels of smoke contamination and give a pre-alarm condition before going to full alarm status," Bailey explains.
In the collection handling area, where it is necessary to minimise damage to stored exhibits, an FM200 compressed gaseous fire suppression system has been installed, while the loading bay is covered by sprinklers.
The value of exhibits displayed at the gallery makes security a major issue in the design of the services. "Cameras provide the primary protection in the galleries and they are sited to provide full coverage of all of the hanging positions," notes Bailey. "These are integrated with the security hanging rail system and the alarm system so if a picture is moved, an audible alarm sounds and the appropriate camera will activate in that area.
Other cameras provide coverage inside and outside of the building and all are linked to a digital storage system to provide high-speed retrieval of data when required. Proximity tag reader devices are used to control access between public and non-public areas.
An additional security feature is the use of a scissor lift in the loading bay area which lifts lorries for unloading. As well as making loading and unloading easier, this ensures that the lorries can't be driven away with their valuable cargoes.
Co-ordination
One of the constraints faced by the design team was the need to conceal the services wherever possible and also distribute around the building. "The architect wanted the services to be hidden wherever possible. This, along with the structural requirements introduced a number of obstacles to routing the services, while keeping them concealed," Bailey recalls. "The majority of the structure is constructed from reinforced concrete. The walls, slabs and several deep beams also limited the options for routing the services," he adds.
There was also a requirement for clean lines, so the plant could not be situated on the roof. Instead, the basement was extended from its original design size and all of the central plant is located here. This meant there was very limited space for the services and a lot of co-ordination was required between FaberMaunsell, the architect and the structural engineers.
One of the main elements of co-ordinated design was the introduction of walls with wide voids at the perimeter of the galleries and the orientation court. "The voids have been used to accommodate most of the primary horizontal ductwork and some of the vertical air distribution routes," explains Bailey. "Low velocity air is introduced at high level through both sides of the walls using linear grilles, which are recessed so only the slots are visible. Extract is at low level through similar grilles."
"The biggest challenge of this project was to provide a signature building that was also functional and would not become outdated in the next five to ten years," observes Bailey. "The key to its success was the high level of co-operation between all of the members of the design team," he concludes.
Suppliers
Controls: Cylon, McCool ControlsAHUs: Thermo Air Systems
Chillers/condensers: Thermo Air Systems (McQuay)
Humidifiers: Coolair
Heater batteries: ABB Flakt
Fans: Liberty Air Technology, Redbro
Boilers: C&F Quadrant (Buderus)
Pumps: IPP (Grundfos, Wilo)
Grilles: Harold & Johnson
Water tanks: Killarney Plastics
Underfloor heating: Valve Control Systems
Valves: Valve Control Systems
Light fittings: Erco, Philips, Concord/Bega, Iguzzini, Marlin, Se’lux, Mike Stone Lighting, CLS Lighting, BBI Lighting, JSB
Lighting control: Erco
Central battery system: Ventilux for emergency lighting
Transformers: Elettromeccanica de Marnate
Switchgear: LV Engineering
Accessories: MK Accent
Distribution boards: LV Engineering (ABB)
Fire alarms: Chubb, VESDA
CCTV: Chubb
Access control: ACT/Europlex
Intruder detection: Chubb (Alarmcom)
PA system: GFD
IT cabling: K-Comm
AV systems: System Video
Rooflight louvres: Levolux
Gas fire suppression: FM200 (Chubb)
Lightning protection: Rainey
Lifts: Industrial Logistics (Kone)
Millennium Wing Extension, National Gallery of Ireland, Dublin
External design conditionsWinter: -5°C db 100% rh (fabric heating) -8°C db 100% rh (air handling systems)
Summer: 25°C db 17°C wb 30°C db for cooling equipment (condensers)
Internal design conditions
Gallery and collection handling areas
Winter: 19°C ± 1°C, 55% ± 5% rh
Summer: 20°C min, 55% ± 5% rh, 24°C max
Rate of change <10% in 24 hours
Bookshop
Winter: 19°C ± 2°C
Summer: 23°C ± 2°C, 30% rh min, 70% max
Ballroom
Winter: 19°C ± 2°C
Summer: 22°C ± 2°C, 30% rh min, 70% max
Toilets
Winter: 19°C ± 2°C
Summer: no cooling provided, no rh control provided
Foyer/orientation court
Winter: 19°C ± 2°C
Summer: 23°C ± 2°C, 30% rh min, 70% max
Restaurants
Winter: 20°C ± 2°C
Summer: 23°C ± 2°C, 30% rh min, 70% max
Winter garden
Winter: 18°C ± 2°C
Summer: 23°C ± 2°C, 30% rh min, 70% max
Multimedia room
Winter: 20°C ± 2°C
Summer: 23°C ± 2°C, 30% rh min, 70% max
Ventilation (fresh air rates)
Gallery areas: 8 l/s per person
Restaurants: 12 l/s per person
Internal heat gains
Occupancy: 60W latent per person, 100 W sensible per person
Small power and IT (average): 5 W/m²
Gallery/ancillary lighting: 25 W/m²
Particulate filtration standards
Galleries and collection handling area:
Stage 1 25%/30% – EU3
Stage 2 80%/85% – EU7
Stage 3 90%/95% – EU8
Internal noise criteria
Galleries: NR35
Bookshop: NR40
Public areas: NR40
Restaurants: NR40
Plantrooms: Not to exceed 80dB(A)
Illumination levels (average over areas)
Galleries: 200 lux ± 50 lux on vertical plane and dimmable
Bookshop: 500 lux
Ballroom: 200-300 lux (dimmable)
Toilets: 200 lux
Foyer/orientation court: 200 lux
Corridors: 100 lux
Restaurant: 200 lux (dimmable)
Plantrooms: 150 lux
Kitchen/Serverys: 200 lux, 500 lux in food prep areas
Multimedia room: 300 lux (VDT: Cat 2)
Emergency lighting: 1 lux/0·2 lux
Electrical loadings
Total connected load: 1 x 1600 kVA transformer serving both wings
Estimated maximum demand: 350 kVA for Millennium Wing
General gallery areas small power and IT: 5 W/m2 (peak value)
Gallery lighting: 30 W/m2 (peak value)
Catering/kitchen areas: 200 W/m2
Multimedia and audiovisual areas: 30 W/m2
Bookshop: 10 W/m2
Fire detection
Classification: L1
IT wiring: Category 5e in Millennium Wing with multimode fibre-optic connection to main hub in existing gallery. Hot water provision
900 l hws calorifier fed from lthw circuit, local electric water heaters in ancillary areas
Source
Building Sustainable Design
Credits
Client The National Gallery of Ireland Architect Benson & Forsyth M&E consulting engineer FaberMaunsell Structural engineer O'Connor, Sutton Cronin Cost consultant Rogerson Reddan & Associates Mechanical contractor L Lynch & Co Electrical contractor Kirby Electrical Main contractor Michael McNamara
No comments yet