The project is the result of a collaboration between National Museums of Scotland (NMS) and the National Trust for Scotland who, in 1992, was gifted the 73 hectare farm of Wester Kittochiside on the outskirts of East Kilbride. This gave a rare opportunity to create a museum that would contrast traditional methods of farming with modern agriculture, encompassing an intact Georgian farmhouse and steading, as well as providing a site for NMS to re-house its Country Life Collection.
The two organisations entered into a joint venture in 1994-5, a combination that was key to securing funding for the project. A total of around £8 million came from public and private funds including the National Lottery, the European Regional Development Fund and other local enterprise agencies.
NMS was the driving force behind the 7200 m2 building and following a limited design competition appointed architects Page and Park. "We wanted a building based on the rural vernacular but that was obviously from the late twentieth century, not a pastiche," says Alastair Cunningham, project development manager for NMS. "We had definite ideas of the type of materials we wanted used: brick, concrete, slate, timber, glass, but no plasterboard."
Design process
NMS took the pragmatic approach that it could not afford the running costs of an air conditioned building, however it still required a space that could maintain stable conditions for the exhibits. The architects together with services engineers Harley Haddow Partnership developed an environmental strategy that took in the criteria set down by the museum's conservators: "The most difficult exhibit to deal with is a mixed collection such as this," explains Chris McLaren of Harley Haddow. "Generally if you're dealing with similar types of materials you can condition the space appropriately, but here you may have a plough made of metal, wood and leather all of which ideally require different conditions to reduce environmental degradation," he adds.
Sudden changes in temperature and/or humidity are considered more damaging to the artefacts than if conditions are allowed to gently wander through wide temperature and humidity zones over a long period of time. The strategy developed required conditions in the spaces to be kept within a wide temperature band of 15-25°C and 45-60% relative humidity. Importantly the conditions imposed included minimising the rate of temperature change to 2°C in one hour and 4°C in 12 hours, and a humidity rate of change of 6% in three hours and 10% in 12 hours.
Harley Haddow with Page and Park followed an iterative design development process, first establishing what they believed was the best architectural/environmental solution in terms of materials and configuration. Opting for a heavyweight structure (with the mass exposed internally) a Tas thermal model was used to predict the building's inherent performance without the installation of any environmental services systems. This explored different building configurations, orientations and fenestration materials to maximise the passive thermal stability of the spaces. Only after achieving a balance between the ideal environmental envelope and the architecture was a strategy developed to overcome the predicted shortfall between the building's passive conditions and the temperature and humidity conditions agreed with the conservators. Repeated cfd simulations of the building with the environmental systems in operation revealed that temperature control was not an issue. However humidity was, and maintaining the correct level all year round would be challenging, particularly as there would be no humidification or dehumidification plant.
Building layout
The three-storey structure is built into the east-west sloping site, with entry on the east via a bridge through to the top floor. The structure predominately comprises of a reinforced concrete frame and walls supporting precast concrete floor planks.
The top level accommodates the ticket point, offices, shop, cafe, picture gallery and orientation area. The main public exhibition space is at the centre of the building on the first floor level (see figure 1). This 'courtyard exhibition' penetrates up through the second floor to roof level creating a triple height space and incorporates a prominent roof light with motorised louvres for night purging when conditions permit. The north side of the courtyard space is inset from the exterior line of the building and comprises full height double glazing and external access for bringing in exhibits.
Enclosed stores sit alongside the courtyard space on both the first and second floors. A series of ramps wrap around these central spaces providing an access route for visitors leading from the top floor orientation area down to the first floor 'courtyard exhibition'. Sporadically inserted along the circulation route are small internal windows giving visitors a glimpse of what the stores contain. "There is now a definite drive towards more accessible storage," says McLaren. "These are areas the public can visit by appointment, where artefacts are much more densely packed than normal exhibition spaces."
Located around the building's perimeter on the first and second floor are a further five stores and several exhibition and workshop spaces. Windows in the east and west corners tie-in with the circulation route providing views of the countryside and the farm.
The largest space, the 'combine harvester store', is situated on the ground floor, this also includes a large restoration workshop; a roller shutter door gives access to the main thoroughfare.
Services layout
As the roof forms a significant part of the building's architecture plant space is accommodated on the lower floor. Advantage has been taken of the sloping site and the large void created between the ground floor store and the hillside. The decision was taken to batter back the slope, seal it with concrete and install a raised chequer plate floor, creating a spacious plant room in what would otherwise have been unused solum space.
A distinguishing feature of the building is the 20 m free-standing chimney on its north side. This is both an architectural device and the route for drawing in supply air to the ahus. Air from the chimney passes through a labyrinth of brick piers in a plenum running beneath the 10 ahus sitting on the raised plant room floor. "The cfd model indicated that airflow over the chimney and labyrinth mass drops the temperature of the air by up to 2°C in the summer period and provides a small amount of free cooling," says McLaren.
The architecture, structure and the m&e services were designed to integrate and a high level of design coordination and drawing information was provided to the installation contractors to ensure this was achieved.
The building has no coverings, voids or finishes which would create services zones, instead services run discretely between the concrete double-tee beams that support the floors, concealing the ductwork and compartmental trunking. The regular sequence of holes cast in the concrete beams are then used to 'plug-in' the services where they are needed.
Long throw adjustable nozzles are used to get the required air distribution in the larger spaces, however there are rare instances such as the auditorium and restoration workshops where false ceilings have been installed and in these cases swirl diffusers have been fitted.
Detectors for the aspirated fire detection system are similarly housed in the concrete beams. The sprinkler system runs directly off the mains with no tank storage or emergency generator. "It's not LPC rules compliant," explains McLaren, "instead it is designed in terms of the water pressure available and the flow we need to achieve at each head in the building." The resulting economical installation satisfies the museums primary concern to protect the collection rather than reduce insurance premiums.
Similarly the artificial lighting is part and parcel of the coordinated distribution strategy – although in some cases this is at the cost of flexibility. Fittings have been kept to a minimum and track lighting is avoided in the exhibition spaces by mounting luminaires on metal rods fixed to the beams. Most of the fittings are industrial in style to complement the feel of the building, with stainless steel uplighters used in the orientation area, and compact fluorescent pendants in the cafe.
Consideration had to be given to the potentially damaging effects of ultraviolet light on the paintings and artefacts in the main public space; this is lit naturally via the full height glazing on the north side, which has had an ultraviolet reducing film applied. Artificial lighting levels are strictly monitored and lux levels are controlled to reduce object degradation.
Services strategy
Harley Haddow was keen to develop a services strategy that met with the client's operational criteria as well as the conservation brief. The resulting ahu installations are all relatively small in capacity (ranging from 0·42 m3/s to 5·32 m3/s). What the modular approach to air treatment lacks in terms of reduced capital costs it makes up for in controllability and operational efficiency.
"The default position of all the plant is off, if conditions in the store areas are satisfied," says McLaren. "If the set point in the room falls out of this band we look to the external conditions or the plant to bring it back under control." Summer is generally not considered to be a problem, but the worst case is in the winter as maintaining temperature control requires the air to be heated, lowering humidity.
The ahus operate according to different controls algorithms depending on the ambient external conditions and in what direction the room condition are drifting out of control. When room conditions are acceptable and within the band of control the ahus shut down. When conditions start to drift out of this band it can do so in any combination, or singularly, as result of high and low temperature or humidity. The plant is prioritised on humidity control rather than temperature, meaning that if both cannot be maintained then the plant will allow the temperature to fall out of the band of control in favour of humidity. As the plant has no means of controlling humidity with either a cooling coil or humidifier, heating and mixing of air are used. The controls software calculates the resultant change that will occur to the temperature before determining the ahu operation.
There are essentially nine control criteria and plant functions associated with the room condition that are only used if the resulting condition is more favourable and stable than the existing condition (see box 'Control criteria').
The ahu installations for the stores also include desiccant thermal wheels to provide latent recovery in addition to the sensible energy recovery from the spaces.
Carbon dioxide sensors are fitted in all of the stores so should air quality fall – eg a large group of visitors is in a store for half an hour– the controls are overridden and the system goes to full fresh air mode.
The overall heating requirement for the building was predicted using the Tas software and the resultant heating surfaces are intended to overcome the fabric losses and infiltration. A combination of different types of heat emitters were installed ranging from wall-mounted radiators in the offices to integrated bench seats with finned tube emitters in the public areas and trench heating at the junction of the floor and glazed facade in the main exhibition space.
The building is served by a central gas-fired boiler installation comprising three condensing boilers with a total heat output to water of 855 kW. These are connected to a flue dilution installation built into an architectural slot on one of the elevations. The main lthw circuitry has been designed to operate at 80°C/40°C flow and return temperatures. Electric cistern heaters are used for local hot water generation.
Monitoring
Extensive monitoring of the controls installation has taken place since the building opened. Part of the design process with NMS Conservation was to utilise the controls installation to provide monitoring and logging of the conditions in the spaces – the location and specification of these sensors was pre-determined with the conservators. This avoided the common occurrence of a completed museum building being retrofitted with a telemetry monitoring system providing the conservators with the same temperature and humidity data required for the controls installation.
Using the play and record function within the Trend Supervisor controls package, data is continually logged and written to cd. This provides internal conditions in all the spaces in the building plus the ambient external conditions.
Graphical data logs have verified the design and operational philosophy. Although swings in humidity occur in both seasons as anticipated low humidity is predominant in the winter period. Low humidity problems have generally been avoided by allowing the space temperature to drop to compensate, and by not running the plant. To date the building has performed better than predicted, McLaren puts this down to the inherent thermal stability of the envelope and the primary control function of being able to shut off the ventilation system when conditions in a space are satisfied.
McLaren believes that the philosophy of a stable envelope, passive environmental systems and modular low capacity environmental installations can be improved. He is currently working on a number of similar projects which aim to reduce the reliance on plant further, providing the required internal conditions by using the ambient external conditions and the inherent stability of heavy mass structures.
Museum of Scottish Country Life, East Kilbride, Kittochside
Controls: Mingavie Controls (Trend)
AHUs: ABB Flakt
Heater batteries: Biddle
Boilers: Hoval
Grilles: Krantz
Water tanks: Balmoral
Light fittings: GFC, Erco, Fagerluft, Thorn, Appollo, JSB, Louis Poulsen
Lighting control: Dynalight
LV transformers: Multiload Technology
Switchgear: Dorman Smith
Distribution boards: Dorman Smith
Fire alarm: Autronica
CCTV: Connelly Security Systems
Intruder detection: Connelly Security Systems
PA system: T G Baker
Specialist containment: Thorsman
Lightning protection: Furse
Accessories: MK Electric
Hot water provision: Heatrae Sadia
Historical weather year for East Kilbride modelled by Tas software.
Stores: 15°C to 25°C and 45% to 60% rh (restricted rates of change)
Main exhibition space: 18°C to 25°C and 45% to 60% rh (restricted rates of change)
Lecture room: 23°C
Circulation: 21°C
Workshops: 18°CB
Education area: 23°C
Offices: 23°C
Entrance/orientation: 23°C
Toilets: 21°C
Shop: 21°C
Whole building: up to 12 l/s/person to suit occupancy
Occupancy: 100 W sensible per person
Small power and IT: 15 W/m2 in the office and 5 W/m2 in all other areas.
Lighting: 25 W/m2
Eurovent 4/5 within all ahus (rural location)
Stores: NR 35
Public areas: NR40
Offices: NR35
Lecture room: NR30
Exhibition spaces 250 lux (supplemented with exhibition lighting)
Lecture room: 500 lux
Circulation: 150 lux
Workshops: 500 lux
Education area: 400 lux
Offices: 500 lux
Entrance/Orientation: 200 lux
Toilets: 150 lux
Shop: 500 lux
Plant rooms: 500 lux
Emergency lighting: 1 lux/0·2 lux
300 kVA lv supply from the local supply authority infrastructure
Measured actual maximum demand: 175 kVA (after eight months operation)
General lighting: 20 W/m2 (excluding exhibition display lighting)
General small power: 5 W/m2
Classification L2
Category 5 tactical wiring to designated points in the building from the main hub.
Mains fed sprinkler installation designed by Amec Fire.
Controls criteria
- Room condition within the control band – plant off;
- humidity control maintained but temperature too low – air heated;
- humidity control maintained but temperature too high – air mixed;
- temperature control maintained but humidity too low – air mixed;
- temperature control maintained but humidity too high – air heated or mixed;
- temperature and humidity too low – plant off or air mix;
- temperature and humidity too high – plant off or air mix;
- temperature too high and humidity too low – air mix;
- temperature too low and humidity too high – air heated or mixed.
Downloads
Plan of the top floor
Other, Size 0 kbInternal temperature and humidity measurements for the first floor tractor store
Other, Size 0 kbExternal conditions for the corresponding period
Other, Size 0 kb
Source
Building Sustainable Design
Credits
Client National Museums of Scotland/National Trust of Scotland Architect Page & Park M&E consulting engineer Harley Haddow Partnership Structural engineer Will Rudd Davidson Cost consultant Thomas & Adamson Mechanical contractor Taylor & Fraser Electrical contractor E J Steill Main contractor Skanska
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