Auxiliary energy

Auxiliary energy is energy consumed by fans, pumps and controls (excluding heat rejection).

 

Select a method for the calculation of auxiliary energy. The options are:

Use SFPs – this method is stipulated for use by mechanically ventilated systems in the UK compliance/certification benchmark buildings, and has limited application elsewhere.

Use SFPs, subject to minimum set by AEV – this method is stipulated for use by mechanically ventilated systems in the UK compliance/certification benchmark buildings, and has limited application elsewhere.

Use SFPs and AEV – sum contributions from explicitly calculated fan power, using SFPs defined at both system and room level, and a term calculated from the auxiliary energy value. This option is appropriate when there are fixed and ventilation dependent auxiliary contributions.

Use AEV (and any zone-level SFP) – calculate auxiliary energy from the AEV, and add in contributions from any ventilation specified at room level, using the room SFP parameters. This is the default, and the recommended method for UK compliance/certification analyses using the UK NCM system data wizard.

Note: these options are not available in VE Compliance, where the auxiliary energy method is forced to ‘NCM compliance (2010) method’ in all cases.

Depending on the choice made for Auxiliary energy method the following available options will be adjusted.

This parameter is only required for UK regulations compliance and certification. Select the appropriate mechanism from the given options covering centralised, zonal and local systems.

The specific fan power (SFP) for the system. This is the power consumption of the system fans for each l/s of air supplied to the rooms by the system, including by means of auxiliary ventilation. For mechanically ventilated systems, the SFP contribution to auxiliary energy may be accounted for either at system level, using this parameter, or at room level, using the SFPs defined in Space Data.

Energy use of fans, pumps and controls, expressed per unit floor area. Auxiliary energy consumption is calculated from this parameter at times when there is a load on the system.

The auxiliary energy value expressed in units of energy per unit floor area per year, normalised to a basis of 3255 hours of operation per year. This parameter is uneditable.

The auxiliary energy value associated with a room when the room’s heating and cooling availability profiles are both off.