Typical Office Wing results from the model, below the artifical sky:Office Wing, lower level
A minimum daylight factor of 2.3 per cent was measured for the lower
office area with a maximum of 6.8 per cent and average of 4 per cent.
Office Wing, upper level
A minimum daylight factor of 1.9 per cent was measured for the upper
office, with a maximum of 6.8 per cent and average 3.2 per cent.
Conclusions
The minimum and average figures are slightly lower than the CIBSE
recommendations, the prime reason being the shading elements. The
model has solid south side shading elements at roof level, which is to be
revised to an open louvred system to improve the conditions.
The effect of the shading system at roof level can be seen by examining
the results between the lower and upper levels. The lower level shows a
small improvement in the figures.
Wessex Water staff predominantly use PCs; as a result, the control of
daylight is an important issue. Too much light would result in blinds
being drawn.
Comparing the model studies with the computer results, the computer
results are higher by the perimeter. This is to be expected as the computer
readings cover the full floor plate, whilst the model studies are spot
measurements only. The maximum computer level of 28 per cent is
directly by the window. In addition, the measured model results have a
built in reduction of 50 per cent to allow for the interior design, with
fitted office space, furniture, colour schemes, changes to height, main-
tenance and light fittings.
Method 2. Computer modelling
A computer study was undertaken to predict daylighting levels within
the street and the central office wing.
The daylight studies assumed a CIE Standard overcast sky.
The daylight study of the open plan offices forming the central wing
was undertaken with a daylight study of the street area indicated in the
figure above.
In both cases the results were analysed at the working plane level.
The street lower level
The minimum daylight level was calculated to be 2.5 per cent.
The average daylight factor has been calculated to be 6.3 per cent. As
with the central office area, this is a good value to achieve for a place
predominantly lit by natural light.
The maximum daylight factor was found to be 22 per cent close to the
windows.
Conclusions
The computer results compare well with the model studies
This is an important area of the building, where visitors gain a first
impression of the building. The space should be well lit, welcoming, and
feel natural in lighting terms.
Calculations 51