– ‘Copper and copper alloys - seamless, round copper tubes for water and gas in sanitary and heating applications’ (+A1:2010) LTHW pipework – treatment for closed heating and cooling systems’ BS 6880-3 – ‘Code of practice for low temperature hot water heating systems of output greater than 45 kW: Part 3 Installation’ BS EN 14336 – ‘Heating systems in buildings. Installation and commissioning of water based heating systems’ Domestic Hot and cold water pipework HSE publication, L8 – ‘Legionnaires’ disease, the control of legionella bacteria in water systems approved code of practice and guidance’ – ‘Specifications for installations inside buildings conveying water for human consumption. Pipe sizing. Simplified method’ WRAS approved fittings from the WRAS Products and Materials Directory available online at WRAS https://www.wras.co.uk/search/products/ Supply (Water Quality) Regulations 2016 Fuel Pipework BS 6891 ‘Specification for the installation and maintenance of low pressure gas installation pipework of up to 35 mm (R11⁄4) on premises’ IGEM/UP/2 ‘Installation pipework on industrial and commercial premises’ Refrigeration Pipework BS EN 12735-1 – ‘Copper and copper alloys - Seamless, round copper tubes for air conditioning and refrigeration Part 1: Tubes for piping systems’ BS EN 14276-2 – ‘Pressure equipment for refrigerating systems and heat pumps - Part 2: Piping - General requirements’
ICT Server Room Ventilation The following section is a minimum specification for the design and installation of the ventilation and associated systems in any server room for Information and Communications Technology (ICT). See Section 4 of the GDB for ICT system requirements. General Requirements Typical server rooms can produce high-density heat loads which can affect ICT equipment. The Contractor shall ensure that environmental conditions are maintained in line with the manufacturer’s recommendations for the equipment to be housed within, or any respective warranty requirements. Security of ventilation openings in the façade shall comply with the GDB. Ventilation Systems, Air Flow and Heat Loads The type of ventilation system required and the strategy to cool the server room will be dependent on the heat generated by the equipment. If a mechanical ventilation system is used this shall be provided with filtration to prevent dust ingress. Server room cooling shall be sized on the sensible heat loads provided by the manufacturers of the equipment to be installed allowing for diversity or the actual measured power consumption of the equipment. An additional load of 10% should be included for future expansion. For modern server rooms it should not be necessary to provide more than 250 W/m² of cooling. Typically, the cooling duty will be in the range of 1.2kW - 6kW for Secondary Schools and 400W – 1kW for Primary Schools. DX or VRF cooling shall be provided to meet the temperatures specified in equipment warranties in peak summertime periods. The normal operating range (set point) shall be designed to meet manufacturer’s recommended requirements. Temperatures may not exceed this range for more than 200 hours a year. The maximum temperature of the room measured at high level above the server racks shall not exceed 28 °C. The minimum temperature of supply air shall be 15 °C. The Contractor minimise the ventilation and cooling required, for example by locating server rooms on the north façade or in areas of the building where there are lower thermal gains and on an outside wall. A ventilation opening to outside or locally controlled extract fan shall be provided to allow for ventilation for occupancy and battery failure. This shall allow for ICT staff who are servicing equipment in the server room; and ventilation required by UPS systems for the safe operation of the batteries to allow for the release of inflammable or corrosive
Special Schools and Designated Units, where needs of pupils may be complex and varied, including pupils with physical difficulties or profound and multiple learning difficulties Category I Where pupils or adults may be wet and partially clothed for a significant length of time, such as swimming pools Category II young children under 5 years old or those with physical disabilities may be wet or partially clothed for a significant length of time. More rapid air movement leads to greater chilling by evaporation and to compensate, a higher design temperature is required Category I Category IV shall only be used in classrooms and other teaching spaces where there is local control over the room ventilation with variable speed control with override control by the teacher. The air quality criteria regarding CO2 levels must still be met. Table 104 Recommended draught criteria for mechanical ventilation systems to provide thermal comfort Category of space/activity Draught criteria to provide thermal comfort Winter Summer and mid-season ∆T (Min maintained operative temp - plume local air temp) Maximum air velocity (m/s) ∆T (Troom, operative - plume local air temp) When Troom ≤25oC or Tcomf Maximum air velocity (m/s) I 1.5 0.15 1.5 0.15 II 2 0.2 2 0.2 III 3 0.25 3 0.25 IV 4 0.3 5 0.3
Criterion 3, the threshold or limit temperature sets a limit beyond which normal adaptive actions will be insufficient to restore personal comfort and the vast majority of occupants will complain of being ‘too hot’. This criterion covers the extremes of hot weather conditions and future climate scenarios. These criteria should be the basis of the thermal modelling of the building, with Criterion 1 defining the minimum requirement for assessing the risk of overheating of School designs. In addition, the asymmetric radiation from hot ceilings in single storey teaching spaces shall be less than 5K in summertime. In order to achieve this hot air must not be trapped at ceiling level and there must be an adequate means to extract hot air from the ceiling zone. For example, cross ventilation can provide adequate airflow across the ceiling and prevent a layer of hot air from building up beneath the ceiling. after consideration of such measures and taking account of other factors that could restrict the use of natural ventilation (e.g. air pollution, traffic noise) the designer deems that the heat load is such that cooling is required, the designer should consider low carbon cooling systems in preference to conventional air conditioning. Such systems could include using cool water from boreholes or drawing in air through earth tubes. Schools be designed without the use mechanical cooling in general teaching spaces. The spaces shall be designed to accommodate ICT equipment heat gains of up to 15W/m² in classrooms, or 25W/m² in practical spaces without the use of mechanical cooling. Practical spaces are generally larger and have a lower occupancy gain per square metre than general teaching spaces which helps to compensate for a higher equipment heat gain. Where the Contractor decides to use of mechanical cooling, for example at times of peak summertime temperatures in areas of particularly high equipment heat load, this shall be justified on heat load and energy efficiency grounds and agreed with the Employer. For example, in teaching spaces where the heat gains exceed 25W/m2 mechanical cooling may be considered. See Section 11.7 for further details on the calculation of internal heat gains. Assessment of Performance in Use Air temperatures rather than operative temperatures shall be used when communicating with the School and to assess thermal comfort in buildings in use, as these are easier for the occupants and the facilities management team to understand. If there appears to be a failure using the criteria based on air
temperatures described below then the Contractor or a heating expert should be asked to consider if the building is overheating. This will require investigation of operative temperatures and comparison with design predictions. The Contractor is required to monitor the indoor environment by recording temperature and CO2 as well as energy consumption as described in Annex 2I: Controls. Performance in use temperatures for assessment of summertime conditions shall be monitored in typical north, south, east and west facing classrooms and in other key spaces, such as: atria, dining spaces, libraries, learning resource centres, admin and head teacher’s offices, server rooms and reprographics rooms, and recorded as part of Building Performance Evaluation, See GDB Section 2.14.6: Building Performance Evaluation (BPE) and seasonal commissioning. Performance in Use Standard for Overheating The following performance in use (PIU) criteria shall be used. It shall be possible to demonstrate within spaces that are occupied for more than 30 minutes at a time that, during the school day, the average internal air temperature does not exceed the average external air temperature measured over an occupied day by more than 5ºC; both temperatures being averaged over the time period when the external air temperature is 20ºC, or higher, except when the diurnal temperature range (lowest temperature from the previous night to the maximum daytime temperature the following day) is less than 4ºC. The buildings shall be able to achieve temperatures within the acceptable range when windows, fans and ventilation systems are operated to reduce summertime temperatures, and the space has the intended number of occupants, numbers and types of computers, data projectors and other ICT equipment. Note: overheating criteria are for the thermal comfort of occupants and are not applicable for equipment such as in server rooms. The extra heat loads from cookers in food and Bunsen burners in science that occur intermittently should be considered separately. If a space fails the PIU criteria above and the internal recorded air temperatures exceed Tmax for Cat III, the Contractor shall examine the temperature records
and investigate whether or not the building is overheating and if the building is performing as designed. To compare predicted design and measured temperatures the Contractor will need to measure operative temperatures as well as air temperatures. This can be done using a small black bulb thermometer or specialist electronic instrumentation. See CIBSE KS16 for further information. The Contractor shall inform the facilities management team that there may be a difference between the air temperature measured in a room and the design temperature (operative temperature). Thermal Comfort for Special Education Needs For comfort conditions for people with special requirements such as those with physical disabilities, BS EN ISO 7730 refers to BS EN ISO/TR 14415:2005. Where pupils have special needs that affect their temperature response, or for very young pupils an assessment of their particular needs will be required which may mean that higher categories of comfort criteria may be needed in particular areas of a school or across a whole school. Design Calculations for Ventilation and Thermal Comfort Ventilation and thermal comfort design for teaching and learning activities shall be proved by modelling for the occupied period. The modelling assumptions affect the calculation results significantly. For this reason, ESFA projects are required to use the following default assumptions regarding the internal conditions in the occupied spaces of the School. Occupied hours assumed 09:00-16:00, Monday to Friday. Occupancy, lighting and small power set to zero during lunch hour in all classroom areas. The School is assumed to be occupied throughout the summer period for modelling of overheating (this provides a degree of future proofing). An external ambient CO2 concentration of 400ppm.