Increasing the population of your building?
- Are you thinking of increasing the population of your building and worried about the effect on the lift service?
- Maybe more people have already moved in and there has been an unacceptable deterioration in service?
- What can be done to ensure a good lift service with an increased population?
Are the lifts performing to their original design?
Many of office buildings in the UK were, and still are, built in accordance with the British Council of Offices (BCO) guidelines. These guidelines indicate that the lift service should be designed based on an occupation density of 14 m2 per person.
However, the population density is very often significantly higher in modern buildings. Companies need to maximise use of their properties and often put as many people in them as they reasonably can. Many types of work such as call centres, IT centres and financial trading floors occupy at far higher than 14 m2 per person.
With a consequent population increase of anywhere ranging up to 150% of what the lifts were designed for, is it any wonder that they do not cope?
Bench marking Performance
Measuring waiting times and how lifts cope with the quantity of people at peak times and comparing these to acceptable levels of service establishes the present performance. This gives you a benchmark to see exactly what level of service is being provided and to then compare this with options for improving service
Getting the best out of what you have got is the first step and there are two elements to consider; performance and reliability.
- There is no compromise, at peak times reliability needs to be 100%
- Performance; each lift needs to operate as quickly as possible whilst travelling to and from floors and the doors should open and close quickly
- With groups of lifts, making sure the supervisory control system is allocating calls to lift cars correctly and efficiently is necessary
Good maintenance with regular adjustment to set up the lifts correctly can optimise the performance of the lifts but unless the lifts are already performing very poorly then we are only talking about small improvements here.
More fundamental changes
If the equipment is old and/or worn out then both poor reliability and performance will result and there is little than can be done to improve things. The older the lifts the more unreliable they will become and obsolescence can also be a factor resulting in long outages.
Modernised equipment if correctly specified will improve the overall performance of the lifts in dealing with an increase in population. Acceleration, deceleration and door operating times can be improved and it may be possible to increase the speed of the lifts.
Modern lift group control systems with advanced algorithms can more efficiently handle the traffic demands imposed on them, often using intelligent logic to ‘learn’ the traffic patterns in a building and adapt accordingly.
A more significant improvement, especially to morning ‘up-peak’ traffic, can be gained by employing control systems based on Hall Call Allocation where the buttons in the lift car are replaced with ones on the landing. This gives advanced information about passenger destinations to the lift control system allowing it to more efficiently despatch cars to match the demand.
What if that is not enough?
Having a thorough understanding of the traffic flows in a building can give an insight into how the overall vertical transportation systems in the building can be improved.
If there are high use floors, e.g. dealer floors in financial institutions, call centres, conference facilities in hotels or restaurants floors, the first consideration is to re-locate these to the ground floor. If that is not possible then re-locating them near the ground floor should be considered combined with the use of escalators or shuttle lifts.
Re-configuring the existing control system, to say only serve certain floors at certain times may also improve the lift service during peak periods.
How can The Lift Consultancy help?
A few services we offer are particularly useful if you find yourself needing more out of your current lift service.
This measures the performance of the existing lifts, expressing the performance in terms of average waiting times at building floors, average interval at the ground floor, long waiting times and the percentage of calls answered in a tranches of time e.g. calls answered in 30/45/60 seconds.
A theoretical study based on the fundamental traffic formula governing lift operation. The study can be used to estimate the existing performance if data logging is not possible. Traffic analysis can also be completed to accurately predict the outcome of upgrading and/or changing the vertical transportation system.
A Feasibility Study will explore the options available and is often combined with a Traffic Analysis and/or data logging exercise. The options will be weighed up with their pros and cons and budget costs and timescales for the various possibilities will be given with recommendations.
There are always reason as for un-reliability but often finding them is not straightforward. A Reliability Review looks at all the data available (break down history, design data, component specifications etc…), obtains feedback and experience from lift passengers and combines this with a site examination for the equipment to determine it’s condition and the levels of maintenance, to ultimately get to the source of the problems and to recommend solutions.
More on these services and as well as related topics can be found by clicking on the links below
|Feasibility Study||Hall Call Allocation|