ALC™ - Automatic Leakage
Control for VEX200 and VEX4000

Patented solution prevents the spread of viruses via the air handling unit


The struggle to maintain a good indoor climate

A ventilation system is already a good weapon in the fight towards maintaining a good, virus-free indoor climate. With a correct and sufficient air exchange, the system helps to ensure that the air is replaced so that viruses, particles and gases are reduced. In all systems with rotary heat exchangers there is a risk that a small amount contaminated air will be mixed up with the clean air when the rotor channels rotate from the polluted airflow to the clean airflow. The leakage problem worsens if there is excess pressure in the contaminated air line.

Vorschaubild_Corona_Lueftungsanlagen_REHVA_Covid19_GuidanceUntil now a purge zone has been installed on the rotor and a trim damper on the extract air inlet to minimise the transfer. Unfortunately this solution is not sufficiently effective – certainly not in a pandemic situation.

In the guide from the Federation of European Ventilation & Air Conditioning Associations (Rehva), you can read the organisation’s recommendations for operating a ventilation system during a pandemic. 


The transfer of contaminated air must be prevented completely 

This transfer of the contaminated air can be prevented using EXHAUSTO’s patented solution, Automatic Leak Control (ALC)™ for VEX200 and VEX4000.

ALC™ is a simple plug & play solution that is available for VEX200 and VEX4000 with rotary heat exchangers. The solution prevents leakage and thereby prevents the spread of viruses, particles and gases via the ventilation system. Activating ALC™ prevents leakage using the VEX control system, regardless of the actual operating situation.

See how the ALC™ functions in on an operating VEX unit

How ALC™ works:

  • A sensor measures the pressure difference between the extract air and supply air chambers in the VEX air handling unit. 
  • The control system in the air handling unit regulates an extract air damper based on the pressure difference.
  • This ensures that the pressure in the extract air chamber is always lower than the pressure in the supply air chamber. 

Automatic leakage control reduces the transfer of exhaust air (EATR, the Exhaust Air Transfer Ratio) to 0%** and prevents recirculation of airborne particles and gases, including virus particles. At the same time this is an energy-efficient solution, since the demand-controlled operation can take place without leakage problems.

Benefits of ALC™ 


EXHAUSTO ALC™*, the patented solution to prevent the spread of disease through rotary AHU 
*Automatic Leakage Control

  • Simple Plug & Play solution, also available as retro-fit
  • Exhaust Air Transfer Rate EATR = 0%** 
  • Perfect solution for hotels, educational buildings, offices, healthcare, shopping centers etc. 
** Tested and validated at Danish Technical University. EATR = 0% based on Eurovent "Air Leakages in Air Handling Units:  Guidelines for Improving Indoor Air Quality and Correcting Performance", 2021, EN308 and EN16798-3.

Learn more under VEX200 AccessoriesVEX4000 rotor section or contact us for further information.


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