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8 - CONTROL
8.1 - AHU with control
■ If the control is supplied by the manufacturer, refer to the manual provided with it.
8.2 - AHU without control
■ If the control is not supplied by the manufacturer, the manufacturer accepts no responsibility for any damage that may occur to the
various controlled components due to faults or improper use. Special precautions must be taken, in particular:
- The temperature in the air handling unit must not exceed the limits (upper or lower) for which it has been designed,
- Low air flow protection must be integrated in the fan control,
- If an electric heater or gas burner is used, safety thermostats must be installed to shut them down in the event of a problem,
- Pressure sensors must monitor the filter fouling level in order to prevent breakage of the filters due to clogging,
- The adjustment values must not exceed the maximum permissible pressure difference on the filters and on the plate heat
exchangers (see AHU technical selection),
- A device must be fitted to protect the motors or issue a notification if the fans become jammed.
- The flow rate and pressure in the duct must be monitored to prevent them from exceeding the limit values,
- Make sure the isolation dampers are open before authorising the ventilation,
- Ensure a fan delay that must be no less than 1minute, and to be adjusted as per the damper actioners rotary speed, when the
electric heaters or GGS are stopped,
- Fit a minimum air flow detecting device if there is an electric heater or GGS
- Protect the ventilation motors and turbines against overspeed,
- Comply with the required insulation and pollution classes for the electrical components and cables to ensure compliance with the
low voltage directive or the regulations in force at the installation site. Take the altitude into account.
■ For VDI 6022 certification, in case of shut-down of the fan or air conditioning system:
- The humidifier must be shut down automatically. A staged shutdown is required to allow the humidification chamber to be dried
prior to complete shutdown.
- The cooling coil's water supply must be shut down automatically. The cooling coil must be dried before the fan shuts down.
- If the shut-down occurs at night or for a maintenance operation, the dampers installed in the ductwork (outdoor air, discharge air
and air inlet) must close automatically to prevent air from entering the system due to wind or inertial forces.
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