SYSTEM OVERVIEW:
System Operation and Design Features
The Cheetah (C3) CUB system is a demand-based energy management system that can be installed to automatically
control commercial kitchen ventilation systems. It is a modular system that can be installed to control multiple
canopies and/or ventilation fans, as required.
The Cheetah system will save energy by controlling the level of ventilation (depending on cooking activity) in
commercial catering environments. This is achieved by continuously measuring the temperature in the extract
canopy duct/s and controlling the extract fan/s and supply fan/s (where applicable), by using Variable Frequency
Drives (Inverters).
Smoke and steam produced by cooking activity is also detected by laser optic sensors fitted to the extract canopy/s.
The Cheetah system will quickly accelerate the ventilation fan/s to maximum speed when smoke or steam is
detected and will continue to run them at full speed for a period of time whilst the smoke and/or steam clears so
that all vapours are fully purged from the canopy/s. After purging the canopy, the system will then return to
operating by temperature control, until the next optic sensor detection. The Cheetah system will always react to the
greatest demand either from temperature, steam or smoke so that conditions in the kitchen are not compromised.
Based on the laws of affinity: a ventilation fan operating at half-speed uses only 13% of the full-speed operating
power, but still moves half the volume of air that it would when running at full-speed. The electricity consumption of
the motors is therefore significantly reduced by running the ventilation fans at lower average speeds.
Further power savings are made from the reduction of conditioned air being unnecessarily extracted through the
ventilation system. Cheetah is designed to be an autonomous system and the fans are set to ramp down to a pre-set
minimum speed when there is little or no catering demand. In most cases, where possible, the pre-set minimum
speed is set to 40% (20Hz) of the maximum operating speed. During normal operation, Cheetah will not stop the
fans, it will only reduce the speed of the fan/s to a set minimum.
The Cheetah system is installed with remote GPRS communications and data-logging facilities. This allows systems
installed at sites to be remotely accessed by Quintex (as required) and the system/s performance operation can be
monitored over a period of time.
Cheetah has been designed so that any fault conditions will cause the connected fans to operate at full-speed (50Hz),
until the issue is corrected. In this way, if a temperature or an optic sensor becomes faulty, the fan/s will run to the
full (set) speed. Similarly, if the connected VFD/s loses digital communications with the Cheetah system, the
connected motors will run at full speed until digital communication is restored.
There is no direct link between Cheetah and a gas interlock system that may be present at a site. However, because
the Cheetah system adjusts fan operating speeds, it can influence the operation of the interlock. As part of the
Cheetah system commissioning process, Quintex will test for the minimum fan speed required to enable the gas
supply, via any interlock system. The minimum speed will always be set above the minimum speed required. Over
time, any site gas interlock system/s should be regularly maintained to ensure that the fan operation detection is
consistent with the operation at the time that the Cheetah system was commissioned. In particular, differential
pressure sensing switches (used by gas interlock systems to sense airflow) can become blocked with contaminants
(grease) and this can cause spurious gas interlock activations unless they are routinely cleaned.
PROTECTION COULD BE IMPAIRED IF THIS PRODUCT IS USED IN A MANNER THAT IS NOT SPECIFIED BY THE MANUFACTURER.
671697
