Rotary heat exchanger (ER)

The product selection program EXselectPRO permits the choice of different wave heights and widths on the rotor - i.e. variable temperature efficiency ratings.

Choose between four different rotor types:

  • Condensing rotor (standard)
  • Enthalpy rotor
  • Sorption rotor 
  • Coated condensing rotor for corrosive environments

Selection of a non-standard rotor will probably entail a longer delivery time.

Function and application

VEX4000 ER

The rotary heat exchanger permits reduced energy consumption by means of its high temperature efficiency of up to 90 %.

In addition, humidity from the extract air can be transferred to the supply air, thus ensuring optimum air quality in practically all application areas.

VEX4000 ER

Residential buildings

For residential buildings we prefer a crossflow or a counterflow heat exchanger over a rotary heat exchanger in order to avoid the risk of transmitting humidity and odours via the rotor.


All ER sections are supplied ready-fitted with a drive unit and rotation monitor and are integrated with EXcon control.

However, the rotor control system can also be used in conjunction with other control systems. 

The drive system consists of a belt moving round the periphery of the rotor, while the motor control system ensures variable rotor speed, depending of the heat recovery requirement. The system is controlled only by a 0-10V signal for regulating the motor speed - (for other automatic control, but incl. rotor control). This means that the drive system is not dependent on a particular control system.

The rotor is solidly seated in the frame construction, and minimal leakage is guaranteed by lip and brush seals.

EXcon uses ModBus for rotor control, which comprises:

  • Rotation monitoring with external rotation sensor
  • Alarm Relay
  • De-icing via diffference pressure measuring 
  • Cold recovery
ALC™, automatic leak control

ALC™, automatic Leakage control

EXHAUSTO’s patent 

Leakage in air handling units with rotary heat exchangers can lead to risk of contamination of the supply air – we have a solution

EXHAUSTO’s patented automatic leakage control (ALC™) continuously measures and controls the pressure difference between supply airflow and extract airflow to ensure that no contaminated air is recirculated to the clean air in the air handling unit.

ALC - printscreen fra animation

How ALC™ works:

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

Automatic leakage control reduces the transfer of exhaust air (EATR, the Exhaust Air Transfer Ratio) to 0%* and eliminates recirculation of airborne particles and gases, including virus particles.

* 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.


You can order your next VEX4000 with ALC™, and ALC™ can also be retrofitted to your existing operating VEX4000.

Learn more about ALC™ here.

Design options

VEX4000 ER, design options

Wave height:

Rotor types

Choose between four different types:

  • Condensing rotor - suitable for ventilation systems without humidification and cooling (Standard)
  • Enthalpy rotor - suitable for ventilation systems with humidification and without cooling. (Option)
  • Sorption rotor - suitable for ventilation systems with humidification and cooling (Option)
  • Coated condensing rotor - suitable for particularly corrosive environments (Option)

Selection of a non-standard rotor will probably entail a longer delivery time.
The rotors can be supplied with an air flushing section, to help minimise the transfer of contaminated air from extract air to supply air. If the flushing function is selected, it will be integrated.

For this it is essential that the static pressure on the supply air side is higher than on the exhaust side.

Dimensions, dimensions table for ER module

ER, heat exchanger section with rotary heat exchanger

Dimensions table

VEX4000 model Height  Length   Depth
VEX4010 [mm] 1309 720 1055
VEX4020 [mm]
1309 720 1275
VEX4030 [mm] 1499 610 1549
VEX4040 [mm]
1599 610 1630
VEX4050 [mm]
1744 610 1755
VEX4060 [mm]
2069 720 1930
VEX4070 [mm]
2069 720 2115
VEX4080 [mm]
2494 720 2325
VEX4090 [mm]
2744 720 2625
VEX4100 [mm]
3024 720 2895

The indicated dimensions are the dimensions for the section - EXselectPRO gives the correct dimensions for the whole air handling unit, including assembly fittings and seals.

Add all about the product series Rotary heat exchanger (ER)


Get free advice on ventilation products and system solutions

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Odensevej 76
DK 5550 Langeskov

Tel +45 6566 1236

Calculation programs

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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