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Air Handling inside buildings and impact Covid - 19
Good ventilation is a key component for reducing the spread.
Covid-19 is primarily transmitted between people through respiratory droplets and contact.
- There is also great concern about the possibility of transmission through the air of various pathogens through HVAC systems
- By controlling within HVAC systems, it could therefore be possible to prevent the spread of viruses
- Ventilation systems become a key resource to clean indoor environments from contaminants, thanks to the extraction of indoor air and the introduction of filtered air from the outdoor environment.
HVAC industry respond to Covid-19 Impact for all buildings
REHVA, the Federation of European Heating, Ventilation and Air Conditioning associations and
ASHRAE, the American Society of Heating, Refrigerating and Air-Conditioning Engineers have provided guidance on the operation and use of building to prevent the spread of COVID-19 related to HVAC systems
The recommendation is to:
- Increase fresh air supply (from outside to inside) and limit air recirculation
- Force the exhaust ventilation systems of certain areas (from inside to outside) to reduce concentration of pathogens
- Optimal humidity control to limit the development of virus
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Crucially Many HVAC installations cannot guaranty optimal comfort for the building occupants
- It is expected that many HVAC installations will be retrofitted in the coming months with particularly AHU equipped with heat recovery system which ensure fresh air supply and energy efficiency
HVAC applications in a building
Air Handling Unit (AHU)
AHUs remain fairley straight forward in term of regulation and therefore prime target to address Covid-19 Issues
- Air Handling Unit (AHU) is designed to regulate and circulate air into a building as part of a HVAC system.
- It is connected to a ductwork ventilation system that distributes the air through the building and returns it to the AHU.
- It generally includes blower, heating and/or cooling elements, filters, dampers and various sensors.
- An air handler that conditions 100% outside air, and no recirculated air, is called makeup air unit(MAU)
- AHU can be combined with a refrigerant circuit and are called recovery unit (RU), packaged unit(PU) or rooftop unit (RTU).
Solution Architecture for AHU : Complete solution for OEM’s
Solution Architecture for AHU :Complete solution for OEM’s
Modicon M172 TVDA
- For any size of installation, connectable or connected machines
- Micro SD card – WebVisu - Connectivity embedded - Scalable
- A complete validated Architecture template for OEMs:
- AFB Libraries
- Electromechanical Components
- Bill of Material
- Scalable and flexible architecture
- Simple integration to any BMS
- via Modbus TCP, BACnet IP or MS/TP or Lonworks
- Easy integration of EC fans from Ziehl Abegg or EBMPapst
Retrofit up / grade Air Handling Units :
Building that systems must be upgraded
Air Mixing used for energy efficiency
- Air mixing could spread virus within the building,
- Adding a heat exchanger keeps inside and outside air separate, and maintains efficiency
UV Sanitation vs Covid-19:
- Despite the debate about the efficacy of UV against Covid-19 is still open, there is a demand to add UV light sanitization to AHU an accessory to manage UV lamps controlling the ozone level
- M171O has the right I/O to manage lamps and the ozone sensor
Solution Architecture for AHU :Â
Solution for Rapid Retrofit or Upgrade / No Coding - parameterization set-up
Temperature Control (heating and cooling):
- Modulating Output, Modulating Valve + Pump
- Electrical Heaters, Pre- and Post-Heating
Humidity Control:
- Humidifier (On / Off or Modulating)
- Dehumidification using cooling and post-heating actuators based on Return Humidity & Dew Point
Ventilation:
- Supply or Supply + Return Fans
- EC fans control based on Air Quality or Pressure
- Management of external dampers
Air Quality control:
- Support for CO2 and VOC sensors
- Air Quality managed through Fans and/or Dampers
Heat Recovery:
- Rotary Wheel (On / Off or Modulating)
- Heat Exchanger (On / Off or Modulating)