2020-07-08

What is Automatic Pressure Balancing, and how does it eliminate contamination?

Automatic Pressure Balancing ensures any air leakage inside an AHU, when a Rotary Heat Exchanger is used for energy recovery, is always in the direction of clean supply air to dirty extract air.

image

This feature, which FläktGroup has had for over 5 years, fulfils the requirements for pressure balancing recently stated by REHVA.

 

  • Secure correct pressure balance between extract and supply air over the rotor
  • Ensures an Exhaust Air Transfer Ratio (EATR) of 0% in accordance of EN 16798-3:2018
  • Prevents contaminated extract air being re-circulated into the supply airstream

 

The leakage at the rotor from extract to supply air is minimized, by measuring and controlling the differential pressure from the extract to the supply air to a low but negative set point.

 

As default the set point is -10 Pa.

 

To achieve this, the extract air damper is equipped with a modulating actuator (0-10VDC), which is controlled to close to reduce the pressure and controlled to open to increase the pressure.

 

Note: the software function in the Climatix controller can also control a modulating damper in the outdoor air. This part of the function is used for Active mixing to create the mixing flow.

 

 

This feature is especially important for healthcare applications, such as ventilation in hospitals, where a mix of vulnrable and healthy people will spend extended periods of time in the same indoor space. But it can also help to protect people in offices, shops and schools among other indoor areas that require HVAC systems to maintain air comfort and safety.

 

Diagram of Automatic Pressure Balancing in AHU

On Friday 3rd July REHVA published updates to their guidance documents referring to Automatic Pressure Balancing to control air leakage inside an AHU when a Rotary Heat Exchanger is used for energy recovery. This update comes as studies by health experts continue in order to understand how viruses can be transmitted through particles suspended in the air.

 

Link to REHVA publication:

https://www.rehva.eu/fileadmin/user_upload/REHVA_COVID-19_specific_guidance_document_-_Limiting_internal_air_leakages_across_the_rotary_heat_exchanger_.pdf

 

FläktGroup have successfully sold products with a solution to the problem for a number of years as part of our eQ product offering and soon this function will be available with our CAIRplus ISYteq controls.

 

For more information about this we invite you to get in touch with our experts:

 

eQ Master:

https://www.flaktgroup.com/en/products/air-treatment/modular-air-handling-units/eq-master-air-handling-unit/

ISYteq Controls:

https://www.flaktgroup.com/en/products/air-treatment/compact-air-handling-units/isyteq-controls-for-air-handling-units/

Recently viewed products

  • AC LINEA AIR CURTAIN

    AC LINEA AIR CURTAIN

    Commercial Air Curtains

    Designed for horizontal mounting above openings, the AC Linea air curtain offers easy installation and carefree maintenance. Available for heights up to 5.5 meters, and suitable for all commercial applications. Choose between electric, hot water or ambient heating and make full use of this flexible and stable solution – regardless of present requirements.

    • Maintenance free
    • High performance
    • Low noise
  • eQ MASTER® AIR HANDLING UNIT

    eQ MASTER® AIR HANDLING UNIT

    Modular Air Handling Units

    Modular air handling unit with an remarkable energy recovery of up to 86% and available in 21 different sizes - when present requirements demand flexibility and adaptability.

    • Tailor made for customer needs
    • Energy Efficient and optimized with integrated control
    • Large variety of high efficiency components
  • CGx Ceiling Air Outlet HEPA FILTER DIFFUSORS

    CGx Ceiling Air Outlet HEPA FILTER DIFFUSORS

    Clean Room Filtration Units

    As the last filter level, the ceiling air diffusers CGF/CGG with integrated HEPA filter fulfills the function of the highly effective separation of particle shaped contaminants of all types including microorganisms. CGO without HEPA filter is designed for extraction or exhaust of polluted air from a clean room. 

    • Used in pharmaceutical industry, laboratories, hospitals, microbiology, electronic industry, and food industry
    • Easy integration in all types of FläktGroup suspended ceilings 
    • Filter classes H13 to U15 in an aluminum frame, with dry or fluid seal
    • For turbulent displacement flow
    • Integrated pressure-gauge connection for monitoring pressure drop
    • Tube for applying test aerosol (measuring of concentration)