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Smarty 2X/3X V
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1.32.1 Cold - Heat Recuperation (no bypass dampers in Smarty 2X/3X V 1.3 versions)
Cold-heat recuperation function is designed to control a heat exchanger. The plate heat exchanger power is controlled by means of a bypass damper.
When the damper is closed, the heat exchanger is used at full capacity. When opening the damper the heat exchanger power is reduced.
The heat exchanger can both heat and cool based on outdoor air temperature. If it is colder outdoors than in the room, the heat exchanger pre-heats
outdoor air by using the room air heat. If it is colder in the room than outdoors, the heat exchanger cools down the outdoor air by using the room air.
The heat exchanger power is reduced to the minimum when the system required supply air temperature is the same as outdoor air temperature. The
higher the difference between required and supply air temperatures, the higher the heat exchanger power is used. Only when the heat exchanger is
used at full capacity, it is allowed to activate other heating/cooling components.
The coefficients of the heat exchanger, heat exchanger PID controller are set to this function.
PID controller output limits are set to bypass damper from which point to start operation. If the bypass damper opens only at several percent the noise
can occur, thus its minimal opening limit is limited. This limit also applies when approaching the full opening.
1.32.2 Plate Heat Exchanger Anti-Frost Protection
This protection is designed to protect the heat exchanger against accumulation of ice as the accumulated ice can damage the structure of the heat
exchanger. Protection activation/deactivation is possible based on:
• Indicated outdoor air temperature
• Indicated extract air temperature
• ndicated extract air temperature difference from the calculated freezing point (this temperature is calculated based on outdoor air temperature,
room air temperature and humidity)
• Based on pressure switch
Possible safeguards (performed in a sequential order as indicated):
1 - Reduction of supply air flow (-30 %)
2 - Outdoor air heating with pre-heater
3 - Bypass damper opening
4 - Unit shut down (based on supply air temperature)
Protection activation conditions and safeguards can be activated optionally. Also time is indicated to switch over from one protection to another one
after time expires. If at least one activation condition is fulfilled, the protection is activated and warning is displayed. It begins from the least energy
• Air flow (m
3
/h). Supply and extract air factor K and maximum system air flow (m
3
/h) is indicated which means 100% air flow.
The fans are controlled by PID controller based on air flow and pressure. Every fan is controlled individually.
It is possible to limit the minimum and maximum fan control signal voltage. By default, minimum 2V voltage is indicated which means that 0V voltage
signal is sent when fans are off, and 2V voltage signal is immediately sent when rotation is required.
1.30.1 Fan Protection based on Rotating Speed
If fans have “tacho” outputs, the fan failure can be identified based on their rotating speed. If the system sends the signal for fans to rotate and they
fail to rotate, then protection is activated, system operation is shut down and alarm is displayed.
1.30.2 Air Flow Protection based on Pressure (only in Smarty 3X V 1.1 version)
Where this protection is activated the system must reach the required pressure or air flow. If the system fails to reach the required air flow or pressure
within the indicated period of time, the protection is activated, unit is shut down and alarm is displayed. This may happen due to failures of air flow/
pressure transmitters, pressure hose defect, clogged flow, impeller defects, incorrect factor K, etc.
1.30.3 Protection of Premises with a Fireplace (only in Smarty 2X/3X V 1.1 versions)
This protection is used for premises with a fireplace. It protects against improper air pressure difference which can result in presence of flue gas
(carbon black) in premises. Pressure switch must be connected to the assigned digital input to measure pressure drop in the premises and inside the
chimney. Upon activation of this protection the pressure switch will shut down the unit and display the alarm.
1.30.4 Slowing Down Air Flows based on Temperature
If supply air temperature is more important than air flow, the function of air flow slowing down based on temperature may be switched on. If full heat-
ing/cooling capacity is used to reach the desired temperature and it is not reached, the air flow is slowed down to have sufficient power to maintain
the desired temperature.
1.30.5 Continuous Temperature Maintenance by Slowing Fans Down
This function is designed to save energy when air flow is changed. It is active when fans are controlled based on percentage, since PID controllers
do it automatically if it is controlled based on air flows or pressure. Fast change of air flows imbalances the temperature maintenance function and
consumes energy until it is balanced again. If a user sets a higher air flow, this function starts gradually increasing the air flow and gradually slows
down the conversion speed when it approaches the set value. In this way the temperature maintenance function suffers less stress and consumes less
energy. If the user reduces the air flow, the system switches off coolers and heaters to prevent from the heat/cold wave and gradually changes the air
flow. After the air flow has been reduced, heaters and coolers continue operating as required.
The following dampers can be connected to the system:
• Supply/extract air dampers (On/Off or OpenClose type). The damper is opened prior to starting fans and closed after fan shutdown.
If On/Off or OpenClose type damper is indicated, proper opening time must be indicated.
