Document Information

Document Type: TechNote

Product(s): Hevacomp Mechanical Designer

Version(s): All

Original Author: Bentley Technical Support Group

Overview

My lumen reports are showing N/A in the number of luminaires result.

Method

This indicates that for the given room index and the selected luminaire there is no corresponding utilisation factors available in the utilisation table and the calculation cannot be completed. In this instance the lumen method is not appropriate for use in calculating the luminaire requirements for this room. You will however be able to use the ‘point to point' method.

For certain combinations of room index and limiting space to height ratio, utilisation data is not available. The utilisation data is either supplied direct from the manufacturer, which is rare, or is calculated from the methods detailed in the CIBSE TM5 document. Part of this calculation uses Table W.1 Zonal multipliers (point sources), which are determined from the room index and the limiting space to height ration for the luminaire. Table W.1 has two columns that partially contain ‘n/a' in place of zonal multipliers. This situation is equivelent to a room containing less than one luminaire. This can occur under two sets of conditions:

• the room index is .75 or less and the limiting space to height ratio is greater than 1.75

• the room index is 1.0 or less and the limiting space to height ratio is greater than 2.25

When the zonal multiplier is nominated as ‘n/a' then a utilisation factor is not available for this condition.

See Also

Product TechNotes and FAQs

Building Product TechNotes And FAQs

External Links

Bentley homepage

HevacompMechanical Designer

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!