Adaptive demand-controlled ventilation

Demand control using patented adaptive pressure regulation (aDCV)


Allows constant pressure-regulated ventilation to be optimised even further

The patented adaptive pressure regulation has been developed by Aldes. It allows optimised operation of constant pressure-regulated ventilation systems with variable airflows. Currently, ventilation in VEX4000 units can be controlled via aDCV. 

Up to 43% savings

Thanks to the patented adaptive pressure regulation system, up to 43% savings on energy costs are possible compared with a constant pressure regulated system (VAV), and up to 19% compared with a demand-controlled unit with constant pressure regulation (DCV).

Further benefits of patented adaptive pressure regulation

Use aDCV and achieve energy savings with lower pressure drops and lower sound levels

With constant pressure regulation (VAV), a constant pressure through the ventilation unit is available at all airflow levels (Fig. 1 - blue line). 

In variable volume flow systems (VAV) – e.g. zone regulation via CO2 or humidity – the ventilation unit needs lower pressure drops in the system in cases where the airflow is lower (Fig. 1 - red line) - and this is precisely what aDCV delivers.

Pressure loss aDCV 

SFP value

aDCV - the patented adaptive pressure regulation lowers the pressure in the ventilation unit when airflow falls, providing only the necessary airflow.

In this way, the ventilation unit uses significantly less energy compared to constant pressure regulation, especially in partial load zones (Fig. 2 - red line) 

SFP value aDCV 

Example, school/office

Here is a typical example of the ventilation requirement. At night, the ventilation system goes into night mode, and a traditional DCV system will reduce the pressure to maybe 50 Pa. During this period the energy consumption for DCV and aDCV will be the same. During the day, when the ventilation requirement will typically vary according to the activity in the different rooms, operation with aDCV will reduce pressure and thus the pressure drop, and in that way save energy compared to DCV.

Example aDCV

The following is a comparison of operation in DCV and aDCV, and shows a saving of some 16% on an annual basis. Our calculations have shown that the savings from controlling ventilation with aDCV rather than DCV will typically amount to 15-20%. 


If we compare aDCV with CAV and VAV, the savings will be even greater.



Get free advice on ventilation products and system solutions

Export Requests:
Odensevej 76
DK 5550 Langeskov

Tel +45 6566 1236

Calculation programs

Use EXHAUSTO's free calculation programs for calculating ventilation plant and system solutions

Go to Calculation Programs
Vex overview

VEX Summary

Get a quick overview of our entire range of compact VEX air handling units with heat recovery.

View the VEX summary here