The Rickard thermo-disc ceiling diffuser
is a mechanically controlled, thermally
powered VAV diffuser. It requires no
external temperature sensors such as a
wall thermostat as each diffuser contains
its own in-built temperature sensing
and volume control mechanism.
Its overall appearance and construction
is very similar to the electronically
controlled diffusers, but has the
advantage that it requires no
external wiring or power supply.
As with the electronic version, air volume
control is achieved through the vertical up
and down movement of the control disc
within the diffuser. In the case of
the thermo-disc diffuser, this movement
is caused by the expansion and
contraction of the diffuser’s
mechanism at set temperatures.
This increases or decreases the aperture
size which allows either more or less
conditioned air to enter the space
and effectively maintain a constant air
movement from 100% down to 25%
of maximum air volume.
Setting and adjusting the room
temperature set point is easily achieved by
rotating the adjustment rings; blue ring for
cooling and red ring for heating. The rings
have calibrated temperature markings
from 19°C to 24°C to suit individual
occupant choice. To access these rings
when installed, occupants simply rotate
the diffuser trim-plate counter-clockwise
and remove it from the diffuser back pan.
