Schematic overview
NOT FOR SALE YET - Temperature control | AC fans | separate units
Solution description
Advanced temperature-based control system designed for dual air handling units. Featured AHU is not equipped with any type of heat recovery system. Exhaust unit relies on supply unit and cannot operate separately. This solution incorporates two fans equipped with AC 3-phase 400 V motors, each with a maximum current of 9.5 A. Furthermore, it features water heater with a pump and a 3-way valve for precise temperature regulation. Robust protection system shields from both air and water frost, ensuring uninterrupted operation even in harsh environmental conditions. This unit also contains a water cooler with a 3-way valve and chiller. Complete control is provided over the supply and exhaust dampers. Filter condition monitoring is included.
Additional specifications and description
This solution is designed to monitor and control an air handling unit that is shown in the schematic below:
Air handling unit consists of seven parts, which are: supply (1) and exhaust (6) air dampers; supply (2) air filter; supply (3) and exhaust (7) fans; air heater (4) and air cooler (5).
Control logic description
Featured solution is specifically designed to control separate supply and exhaust AHU. They are not linked with any type of heat recovery system, but still fulfill the ventilation and air conditioning needs of specified space. The automation system is developed to create a reliance between supply and exhaust units. Because of that, AHU switch on and off simultaneously. Moreover, supply AHU is defined as a base unit, meaning that separate operation of exhaust unit is impossible.
This solution ensures full automation of the AHU operation, relying on sensor readings. The HVAC controller DRPUM is equipped with predefined logic for different AHU components.
To optimize performance and prevent potential damage to air dampers, both supply and exhaust air dampers open 30 seconds before activating the corresponding fans. This precaution is particularly crucial for high-flow AHU.
A dual differential pressure transmitter, HPD-G-1K0, is employed to assess the condition of the supply air filter. These measurements are delivered to the DRPUM (the master device). If the pressure drop across the filter surpasses the setpoint, a maintenance alert is triggered for the user. Despite a clogged filter, the AHU continues to operate without interruption.
The speed of both supply and exhaust fans can be adjusted manually or automatically using frequency inverters FI-E-44095E2. The supply fan operation is regulated by the HPD-G-1K0, while the pressure transmitter HPS-M-1K0-2 controls the exhaust fan. In case of mechanical issues such as jamming or bearing breakdown, resulting in no pressure drop, the master device takes corrective actions: it shuts off the frequency inverter, closes the air damper, and notifies the user of the error. Both differential pressure transmitters can also be used to maintain a specific pressure difference in automatic mode.
The air heater's operation is regulated by a duct temperature and humidity sensor, DSTHM-2. If the measured temperature exceeds the desired value, the 3-way valve gradually closes, reducing the hot water supply to the air heater. Conversely, if the temperature falls below the desired setpoint, the valve opens incrementally. The pump operates at a constant speed to maintain hydraulic balance.
The air heater features two types of frost protection: air and water. An air frost protection thermostat, placed immediately after the heater, measures the air temperature. If the air temperature falls below 10°C (adjustable), the sequence involves stopping both supply and exhaust fans, closing air dampers, and fully opening the 3-way valve. Normal operation resumes when the air temperature after the heater exceeds the setpoint.
Water frost protection utilizes a temperature sensor for fluid pipes, DTP-M, located at the air heater exit. If the measured water temperature drops below 25°C (adjustable), the fans stop, air dampers close, and the 3-way valve fully opens. Operation resumes when the water temperature surpasses the setpoint.
The functioning of the air cooler relies on measurements from the room temperature and humidity sensor, RSTHM-2. If the actual temperature exceeds the desired value, the 3-way valve opens, allowing cold water to enter the air cooler. The valve position is determined by the temperature difference; the warmer the room, the wider the valve opens. Duct temperature sensors are not used for air cooler due to the potential warming of air while passing through the fan and ducts.
System configuration
This solution contains a network gateway, DIG-M-2, providing users with access to the online HVAC platform, SenteraWeb. Connection can be established through an Ethernet cable or a Wi-Fi network, offering remote monitoring and adjustment of settings for connected HVAC devices via the internet. Additionally, the system supports data logging.
Air handling unit consists of seven parts, which are: supply (1) and exhaust (6) air dampers; supply (2) air filter; supply (3) and exhaust (7) fans; air heater (4) and air cooler (5).
Control logic description
Featured solution is specifically designed to control separate supply and exhaust AHU. They are not linked with any type of heat recovery system, but still fulfill the ventilation and air conditioning needs of specified space. The automation system is developed to create a reliance between supply and exhaust units. Because of that, AHU switch on and off simultaneously. Moreover, supply AHU is defined as a base unit, meaning that separate operation of exhaust unit is impossible.
This solution ensures full automation of the AHU operation, relying on sensor readings. The HVAC controller DRPUM is equipped with predefined logic for different AHU components.
To optimize performance and prevent potential damage to air dampers, both supply and exhaust air dampers open 30 seconds before activating the corresponding fans. This precaution is particularly crucial for high-flow AHU.
A dual differential pressure transmitter, HPD-G-1K0, is employed to assess the condition of the supply air filter. These measurements are delivered to the DRPUM (the master device). If the pressure drop across the filter surpasses the setpoint, a maintenance alert is triggered for the user. Despite a clogged filter, the AHU continues to operate without interruption.
The speed of both supply and exhaust fans can be adjusted manually or automatically using frequency inverters FI-E-44095E2. The supply fan operation is regulated by the HPD-G-1K0, while the pressure transmitter HPS-M-1K0-2 controls the exhaust fan. In case of mechanical issues such as jamming or bearing breakdown, resulting in no pressure drop, the master device takes corrective actions: it shuts off the frequency inverter, closes the air damper, and notifies the user of the error. Both differential pressure transmitters can also be used to maintain a specific pressure difference in automatic mode.
The air heater's operation is regulated by a duct temperature and humidity sensor, DSTHM-2. If the measured temperature exceeds the desired value, the 3-way valve gradually closes, reducing the hot water supply to the air heater. Conversely, if the temperature falls below the desired setpoint, the valve opens incrementally. The pump operates at a constant speed to maintain hydraulic balance.
The air heater features two types of frost protection: air and water. An air frost protection thermostat, placed immediately after the heater, measures the air temperature. If the air temperature falls below 10°C (adjustable), the sequence involves stopping both supply and exhaust fans, closing air dampers, and fully opening the 3-way valve. Normal operation resumes when the air temperature after the heater exceeds the setpoint.
Water frost protection utilizes a temperature sensor for fluid pipes, DTP-M, located at the air heater exit. If the measured water temperature drops below 25°C (adjustable), the fans stop, air dampers close, and the 3-way valve fully opens. Operation resumes when the water temperature surpasses the setpoint.
The functioning of the air cooler relies on measurements from the room temperature and humidity sensor, RSTHM-2. If the actual temperature exceeds the desired value, the 3-way valve opens, allowing cold water to enter the air cooler. The valve position is determined by the temperature difference; the warmer the room, the wider the valve opens. Duct temperature sensors are not used for air cooler due to the potential warming of air while passing through the fan and ducts.
System configuration
This solution contains a network gateway, DIG-M-2, providing users with access to the online HVAC platform, SenteraWeb. Connection can be established through an Ethernet cable or a Wi-Fi network, offering remote monitoring and adjustment of settings for connected HVAC devices via the internet. Additionally, the system supports data logging.
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