National Calculation Methodology (NCM) - Scottish Government
National Calculation Methodology (NCM) - Scottish Government National Calculation Methodology (NCM) - Scottish Government
d. For spaces with mechanical extract: the product of the extract rate provided by the user for the actual building, the annual hours of operation (from the NCM Activity Database), and the appropriate SFP from Table 5. If the zone is heated only, mechanically ventilated, or air-conditioned, then the auxiliary energy should also include the energy from paragraph 45.a, 45.b, or 45.c, respectively. Table 5: Specific fan power for different ventilation systems in the notional building System type Specific fan power W/(litre/s) Centralised balanced mechanical ventilation 2.0** system Zonal supply system 1.2** Zonal extract system serving multiple spaces, 0.8 i.e. fan is remote from zone Local extract serving a single area, i.e. fan is 0.5 within zone (e.g. toilet extract) ** If the activity in the space requires the use of higher levels of filtration, e.g., High Efficiency Particulate Air (HEPA) filters, the specific fan power is increased by 1.0 W/(litre/s). 46. In the notional building: a. No allowance should be made for heat recovery equipment. b. No allowance should be made for demand-controlled ventilation. 47. The overall system efficiency (including generation and distribution) for the water heating system in the notional building must be taken as 0.45, and the fuel must be as specified in paragraph 41. The energy demand must be taken as that required to raise the water temperature from 10 o C to 60 o C based on the demands specified in the NCM Activity Database. The Activity Database defines a daily total figure in litres/(m 2 .day). If users of DSMs wish to distribute this demand over the day, then the daily total should be distributed according to the occupancy profile. 48. The notional building must be assumed to have no power factor correction and none of the adjustment factors from clause 6.1.9 in Section 6 apply. Installed Lighting Power Density 49. For general lighting in the notional building: a. For office, storage, and industrial spaces, divide the illuminance appropriate to the activity in the space, as given in the NCM Activity Database, by 100, and then multiply by 3.75 W/m 2 per 100 Lux. This includes all spaces that accommodate predominantly office tasks, including classrooms, seminar rooms, and conference rooms, including those in schools. 18
. For other spaces, divide the illuminance appropriate to the activity in the space, as given in the NCM Activity Database, by 100, and then multiply by 5.2 W/m 2 per 100 Lux. 50. For display lighting in the notional building, take the display lighting power density, in W/m 2 , appropriate to the activity in the space from the NCM Activity Database. 51. In all cases, the duration of the lighting demand must be as per the activity schedule in the NCM Activity Database. 52. It must be assumed that the general lighting in the notional building has local manual switching in all spaces. Calculation methods for the impact of controls on lighting energy demand must be at least as detailed as the procedures specified in the SBEM Technical Manual 18 . The Target Emission Rate (TER) 53. The notional building, with the parameters as defined above, must be used as the basis of determining the CO2 emission Target Emission Rate (TER), irrespective of the calculation method used to determine the heating and cooling demands themselves. For the actual building, DSMs may represent HVAC systems explicitly, but will be required to report overall seasonal performance parameters as an aid to checking - see paragraph 7.c. 54. The TER must then be calculated by adjusting the emissions of the notional building and reducing them by an improvement factor as specified in the equations in clause 6.1.7 of Section 6. The improvement factor differs depending upon whether a building (or part of a building) is either heated and naturally ventilated or heated and mechanically ventilated/ air conditioned. Accordingly, the level of improvement for a building which contains areas with different servicing strategies, IFb, is calculated by applying the relevant improvement factor, IFi, to each area of the building with a different servicing strategy, weighted by the CO2 emissions of that area from the notional building, kgCO2,i. Where ( IFi kgCO2 , i ) ∑ ( kgCO2 ) = ∑ ∗ i IF b , IFi represents the improvement factor from clause 6.1.7 of Section 6 that applies to each area i of the building. If the area is designed for mixed-mode operation, then the improvement factor for heated and naturally ventilated space must be used. kgCO2,i is the carbon dioxide emissions, in kg, from the notional building produced in area i, where i refers to each area of the building that has a different servicing strategy. 18 Available for download from the NCM website at www.2010ncm.bre.co.uk. 19
- Page 1 and 2: Directorate for the Built Environme
- Page 3 and 4: Contents. Contents 3 List of Tables
- Page 5 and 6: BER Building Emission Rate BSD Buil
- Page 7 and 8: 2 Approved Software Tools. 5. Non-d
- Page 9 and 10: of building or building features. T
- Page 11 and 12: Building Fabric 26. The U-values in
- Page 13 and 14: Methods that use flow networks are
- Page 15 and 16: egarded as being mechanically venti
- Page 17: d. The electricity used by fossil-f
- Page 21 and 22: Table 6: Carbon dioxide emission fa
- Page 23 and 24: 4 Energy Performance Certificates (
- Page 25 and 26: 5 Input Data to Approved Tools. 74.
- Page 27 and 28: d. Any fuel used in generating the
- Page 29 and 30: Table 8: Measurement and other conv
- Page 31 and 32: pressure filtration is also defined
- Page 33 and 34: Building Type Description 16 Non-re
- Page 35 and 36: Activity Type Description 33 Generi
- Page 37 and 38: Construction and Glazing Databases
- Page 39 and 40: ID Category Construction Name 518 P
- Page 41 and 42: ID Category Construction Name 565 P
- Page 43 and 44: 101. It may also be that more compl
d. For spaces with mechanical extract: the product of the extract rate provided by<br />
the user for the actual building, the annual hours of operation (from the <strong>NCM</strong><br />
Activity Database), and the appropriate SFP from Table 5. If the zone is heated<br />
only, mechanically ventilated, or air-conditioned, then the auxiliary energy<br />
should also include the energy from paragraph 45.a, 45.b, or 45.c, respectively.<br />
Table 5: Specific fan power for different ventilation systems in the notional building<br />
System type Specific fan power W/(litre/s)<br />
Centralised balanced mechanical ventilation<br />
2.0**<br />
system<br />
Zonal supply system 1.2**<br />
Zonal extract system serving multiple spaces,<br />
0.8<br />
i.e. fan is remote from zone<br />
Local extract serving a single area, i.e. fan is<br />
0.5<br />
within zone (e.g. toilet extract)<br />
** If the activity in the space requires the use of higher levels of filtration, e.g., High<br />
Efficiency Particulate Air (HEPA) filters, the specific fan power is increased by 1.0<br />
W/(litre/s).<br />
46. In the notional building:<br />
a. No allowance should be made for heat recovery equipment.<br />
b. No allowance should be made for demand-controlled ventilation.<br />
47. The overall system efficiency (including generation and distribution) for the water<br />
heating system in the notional building must be taken as 0.45, and the fuel must<br />
be as specified in paragraph 41. The energy demand must be taken as that<br />
required to raise the water temperature from 10 o C to 60 o C based on the demands<br />
specified in the <strong>NCM</strong> Activity Database. The Activity Database defines a daily total<br />
figure in litres/(m 2 .day). If users of DSMs wish to distribute this demand over the<br />
day, then the daily total should be distributed according to the occupancy profile.<br />
48. The notional building must be assumed to have no power factor correction and<br />
none of the adjustment factors from clause 6.1.9 in Section 6 apply.<br />
Installed Lighting Power Density<br />
49. For general lighting in the notional building:<br />
a. For office, storage, and industrial spaces, divide the illuminance appropriate to<br />
the activity in the space, as given in the <strong>NCM</strong> Activity Database, by 100, and<br />
then multiply by 3.75 W/m 2 per 100 Lux. This includes all spaces that<br />
accommodate predominantly office tasks, including classrooms, seminar<br />
rooms, and conference rooms, including those in schools.<br />
18
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