Energy Calculation & Classification for Lifts

Session 11 Paper 2, CIBSE Technical Symposium, Liverpool John Moores University, Liverpool
11-12 April 2013

Lifts are an essential element in the operation of any building in order to transport the population from floor to floor. This makes the selection of lifts a key issue for architects and lift consultants during the building design phase. Besides taking into account the building design characteristics (net usable area, height, distance between floors, etc.) a lift system designer must also consider the intended use of the building (population expected to work or live on each floor, the level of demand, the traffic pattern, etc.).

Nowadays energy efficiency also has to be considered in order to achieve an acceptable carbon footprint. Building classification systems such as BREEAM, LEEDS and Green Star classify the whole building of which lifts are a small part of the overall credit score. 

Lifts can be either "running" , when they are moving, or "standing", when they are stationary: either idle or in standby. Whilst the energy consumed in each operating condition can be easily measured, for example, using the methodology described in the ISO 25745-1:2012 (1), or estimated from the machanical and electrical components of the lift, there are no clear rules on how to estimate the other paramenters relevant to the use, which are required to produce a calculation method.

This paper describes s calculation model for daily energy consumption based on the ISO work and indicates how a classification system was developed (which is still out for international discussion). How computer simulation was used to obtain key parameters used in this paper has been a subject of a previous paper (2).