One of the most frequent requests we receive is the calculation or evaluation of the "capacity" of a chair, a term which, from our point of view, is unrelated to testing, as it is a data not comparable and does not take into account the conditions of use. Some time ago, we had published an article on this topic in which we explained that, within the scope of the standard that defines the requirements for seating in the home and non-domestic use, the loads and cycles were conceived for use of the seat by people weighing up to 110 kg, while there is no mention of capacity.
You can find the article by clicking on the following picture:
Instead, it is correct to refer to
the maximum weight of the person who can use a particular chair.
The European (EN) and American (ANSI-BIFMA) standards in force are based on a figure that represents the
95th percentile of the weight, therefore
110 kg and
125 kg respectively.
Should you wish to check the strength and durability of a chair intended for a heavy user, there are currently no technical standards
in Europe. For the
American market there are two standards designed for seating used by heavy people: they define test loads that consider over the 99th percentile of its population.
The two standards we are referring to are:
- -ANSI-BIFMA X5.11, “General-purpose large occupant office chairs”: for people weighing up to 400 lbs (181 Kg);
- ANSI-BIFMA X5.41, “Large occupant public and Lounge seating”, which has two levels:
- Users to 400 lbs (181 Kg);
- Users to 600 lbs (272 Kg).
These two standards also include a minimum seat width requirement.
But how is Europe moving in this regard?Given the numerous requests to be able to test one's product for a heavier user, a working group within CEN is currently studying a
guide, which will allow the recalculation of loads for some tests actually influenced by the weight of the user.
This guidance will apply to seats for people weighing
between 110 kg and 180 kg (the 180 kg corresponds to the 99th percentile of the European population).
When this guide is published and available, the standard to be applied will always be chosen based on the intended use of the product (domestic, non-domestic, external, ..) but it will be possible to calculate the test loads for the weight of a user between 110 kg and 180 kg.
At CATAS we have already satisfied some of our customers' requests using this guide, although to date the document is still in its draft stage.
As always, we will give you more information once this guide is published.
For info:
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