Retrotec USACE - Manual (Page 443)

Appendix N N13
N.3.6 Carpet plots
Measured data in great quantities is impossible to get a grasp of if presented
in tables. Carpet plots have become better known lately, even though still not
common. Therefore for the time being they are primarily tools which should
be used from experts only. A plotted colored variable is visualized over a period
of time in a diagram, which gives a signifi cant pattern that looks like a carpet.
In carpet plot usually the time of day is drawn on the ordinate (y-axis). On the
abscissa (x-axis) the day (or date) is drawn. The value of the variable under ob-
servation is encoded as a color value at the coordinate of time and date.
The visualizations show the following things:
The carpet plots of power and water consumption show distinct weekly ■
patterns for the occupancy of the building (Monday until Friday ca.
8am–9pm, weekend and holidays no use). This profi le is an indication
for a constant use. The reason for occurrence of signifi cant water con-
sumption at night in August and September, also a few in beginning of
2009, is an irrigation system on the roof of one of the building parts that
has a green roof.
The carpet plot of the consumption of district heat also shows weekly
■
patterns, but not so clear. An increase of the daily operating hours in
winter and blur of the pattern can be detected. The reason for this is
an outdoor air temperature dependent control of the heating operation
schedule. The beginning of heating is thus up to 3 hours earlier than in
the standard operation schedule.