Air Quality Control (AQC)

Ensures correct pressure balance even when the external pressures are changing, preventing the transfer of exhaust air to the supply air.

The challenge

Rotary heat exchangers are highly efficient, but they could come with a challenge: if pressure conditions in the duct system fluctuate for example in a DCV system, there’s a risk that extract air leaks into the supply air. This can transfer odors or contaminants back into the building – something no facility manager wants. 

Air Quality Control (AQC) in GOLD air handling units is designed to ensure optimal indoor air quality by preventing the transfer of exhaust air to the supply air. 

Learn more about how internal leakage is minimised in GOLD units in our technical guide

Why should you activate it?

In demand controlled ventilation (DCV) systems, fan speeds and airflow often change. This can cause pressure differences, making it possible for contaminated extract air to leak into the supply air. In these cases, the standard adjustment plates provided in the GOLD unit may not always prevent contamination or odor transfer between areas. This could lead to complaints about hygiene and air quality from the tenants.

Air Quality Control (AQC) solves this problem. When AQC is activated, the system automatically adjusts for pressure differences across the heat exchanger. This keeps the airflow direction correct and ensures that only fresh, clean air is supplied throughout the building. As a result, indoor air quality is protected and occupant comfort is maintained.

Main benefits

AQC gives you peace of mind that your ventilation system delivers what it promises: clean, healthy air.

Key benefits include:

  • Contamination prevention: AQC continuously manages pressure balance across the rotary heat exchanger, ensuring that extract air cannot leak into the supply air stream and that tenants always receive fresh, uncontaminated air.
  • Health and safety: Reduces the risk of spreading odors or pollutantss from exhaust air back into occupied spaces.
  • Compliance and reputation: Helps maintain compliance with air quality regulations and protects the reputation of your property by preventing complaints related to indoor air quality.

Air Quality Control is especially useful in buildings where hygiene and comfort are critical, such as multi-family homes, elderly homes, hotels and offices with variable airflow systems.

How does it work?

The AQC function uses a dedicated pressure sensor to measure the pressure difference across the rotary heat exchanger.

Here’s how it works:

  • During commissioning, a pre-adjustment is made using standard commissioning plates and a modulating damper actuator is installed in the extract air duct.
  • The system continuously controls the extract air damper to maintain the correct pressure balance, ensuring that negative pressure in the extract air section never exceeds that in the supply air section.
  • All settings, monitoring, and adjustments can be managed via the GOLD unit’s handheld terminal or web interface.
  • Internal leakage values (OACF/EATR) can be read and reported for compliance and quality assurance.

What can you save?

Air Quality Control is not about energy savings – it’s about air quality and compliance. By preventing contamination, you avoid costly complaints, potential health risks and the need for corrective actions. For sensitive environments, this function is invaluable.

Bottom line: Air Quality Control is a simple safeguard that ensures your ventilation system delivers what it promises: clean, healthy air.