L-DALI User Manual
281
LOYTEC
Version 5.2
LOYTEC electronics GmbH
-
Sun Azimuth (
nviSunAzimuth
): Depending on the orientation of the
window, the sun can only shine into the room from a certain azimuth in
the morning (
nciMinAzimuth
) to a certain azimuth in the evening
(
nciMaxAzimuzh
).
-
Outdoor lux level (
nviSunLux
): The glare protection will be activated if
the measured outdoor lux level is above
nciSlHiLimGlare
. If the outdoor
lux level falls below
nciSlLoLimGlare
the glare protection will be
deactivated. These two configuration properties implement a hysteresis.
-
Surrounding
buildings/objects:
The
network
variable
inputs
nviGlobalGlare
and
nviGlobalShadow
can be used to provide geometry
information on surrounding buildings/objects. Glare protection is active
when the corresponding bit in
nviGlobalGlare
is active and the one in
nviGlobalShadow
is inactive.
Alternatively the need for glare protection can be computed by a separate device. In this
case the network variable input
nviGlare
can be used to override the automatic glare
detection algorithm.
8.2.9.2 View Protection
To protect rooms against prying eyes the sunblind can be closed automatically when the
indoor light is switched on and the outdoor light level (
nviSunLux
) falls below the indoor
light level (
nviIllumLev
). To avoid that the sunblind opens and closes repeatedly a
hysteresis can be configured using the configuration property
nciViewProtHyst
.
8.2.9.3 Heating/Cooling
If the room is not occupied, the L-DALI can close the sunblind to provide thermal isolation
in order to save energy.
The network variable input
nviTerminalLoad
is used to inform the controller of the current
heating/cooling demand of the system. Positive values indicate that cooling energy is
required, while negative values indicate that heating energy is required.
If
nviTerminalLoad
is not bound, but
nviOutdoorTemp
is bound, heating demand is
assumed if the moving average outdoor temperature falls below 12°C/54°F, cooling demand
is assumed if it is above 19°C/66°F.
The algorithm takes the following parameters into account:
-
Outdoor lux level (
nviSunLux
):
The energy of the sun can be used to
warm a room. The configuration property
nciSlHiLimTem
defines the lux
level above which the sun energy will make a noticeable contribution to
warm the room if the sunblind is open. The configuration property
nciSlLoLimTem
define the lux level below which the sun energy is too
low to warm the room. To avoid that the sunblind opens and closes
repeatedly a hysteresis can be specified using the configuration property
nciTermSLHyst
.
-
Temperature:
The outdoor temperature (
nviOutdoorTemp
) is compared
with the indoor temperature (
nviIndoorTemp
). Depending on whether the
system is in heating or in cooling mode and on the temperature difference
the sunblinds are closed to increase thermal isolation of the room. To
avoid that the sunblind opens and closes repeatedly a hysteresis can be
specified using the configuration property
nciTermTempHyst
.
