Occurrence of typical lighting related problems within the LESO-SEB

The detailed evaluation of the 23 questionnaires returned by the LESO-SEB occupants made it possible to get a good understanding of which typical lighting related problems may be bothering occupants in ADS-equipped offices the most. The MAV and nconcerned-values as defined in Subsection 3.1 are used in Table 1 to quantify the annoyance of different typical problems. First of all, we observe that the maximum MAV is 34% and the maximum number of directly concerned occupants nconcerned is 6. These low values underline the general impression that occupant

satisfaction within the examined ADS-equipped is quite good. Furthermore, Table 1 shows that all problems scoring MAVs of 20% or higher are related to situations where too much daylight is bothering the occupants. Specific interviews with the six concerned occupants revealed that four of them manage to quickly “resolve” those “daylight overprovision”-problems using the blind systems in most cases. Two of them, however, found it not so easy to quickly resolve these problems. When looking at the nconcerned-value of problem 6, one might find it surprising that it equals 3 instead of 2. This means that there is one occupant who is not particularly annoyed by “daylight overprovision”-problems, but who still feels that those problems are not so easy to resolve in the rare cases where they occur. Agreement with problem 5 was found to be 17% with three directly concerned occupants. Those three occupants were found to often work with completely lowered window blinds and do therefore often not benefit from the advantages of their daylighting systems. The workplace of the person directly concerned by problem 7 is located at a considerable distance from the window.

Table 1: Lighting related problems experienced by LESO-SEB occupants, their mean annoyance values (MAV) and the number of persons directly concerned by the problem (nconcerned).

No

Problem

MAV

nconcerned

1

Office seems too bright.

34

6

2

Glare problems.

29

6

3

Too much light on workplane.

22

3

4

Too much daylight in office.

20

3

5

Office seems too dim.

17

3

6

Glare problems difficult to handle.

15

3

7

Not enough light on workplane.

14

1

8

Daylight distribution not appropriate.

13

0

9

Difficult to find appropriate lighting configuration.

11

1

10

Outside view obstucted.

1

0

11

Not enough daylight in office.

1

0

12

Difficult to tell about outside weather conditions.

1

0