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Rotary heat exchangers

85%

Efficiency

Rotary heat exchangers (thermal/rotary wheels) recover energy between exhaust and supply air streams to lower HVAC power use and stabilize indoor comfort. Depending on the wheel type, they either only transfer sensible heat or both heat and moisture. Compact design, less need for maintenance, and long service life make them a reliable choice for commercial, residential, and industrial ventilation.

Key operating parameters

Performance characteristics

Airflow volume

Designed to handle air volumes from 100 m³/h to 50,000+ m³/h, making them suitable for any system, from compact residential to large industrial and commercial installations.

Operating temperature

−25 °C to +50 °C.

Relative humidity range

Rotary heat exchangers are designed for reliable operation at a relative humidity of 10–95%.

Pressure difference

Typical systems operate at 300–500 Pa between flows, recommended up to 1000 Pa.

Frost resistance

Thanks to continuous movement and internal energy transfer, rotary heat exchangers are frost-resistant. This ensures stable operation even at low outside temperatures without the need for electric or bypass defrosting.

Installation orientation

ZERN ENGINEERING rotary heat exchangers are mainly installed in a vertical orientation, but horizontal installation is also available if required.

Technical features

Design and structure

Principle of operations

A rotary heat exchanger consists of a rotating wheel made up of numerous small air ducts or channels, typically constructed from aluminum. This wheel rotates between two separate air streams: the warm exhaust air and the cooler incoming fresh air. As the wheel turns, it absorbs heat from the outgoing air and transfers it to the incoming air, effectively recovering energy that would otherwise be lost. In units equipped with hygroscopic coatings, moisture can also be transferred, facilitating humidity control. 

Rotor matrix
  • Foil thickness: 0.055 or 0.07 mm
  • Wave height (corrugation): 1.4 / 1.6 / 1.8 / 2.1 mm (trade-off between pressure drop and efficiency).
  • Rotor width (depth): 100 or 200 mm for compact or high-capacity systems.
  • Surface treatments (R-E-EX / R-N-EX): hygroscopic or sorptive coatings (e.g., silica gel / molecular sieve) enable latent-heat and moisture transfer.



Casing materials
  • Galvanized steel — cost-effective, durable for standard applications.
  • Aluminum — lightweight, corrosion-resistant where weight matters.
  • Stainless steel (AISI 304/316) — for harsh, coastal, or chemically aggressive environments.

Modifications

Main components

Rotor (matrix)


Cylindrical stack of flat and corrugated aluminum foil providing large surface area for transfer.

Casing


The main load-bearing metal structure in which all elements of the unit are housed

Drive


An electric motor and controller (optional), coupled with a belt drive system, rotates the rotor at a controlled, steady speed, typically between 10 to 20 RPM, adjustable to balance efficiency and control.



Sealing system


High-quality seals minimize leakage and cross-contamination.





Modifications

Applications


  • Residential buildings — apartments, multi-family housing, private homes.
  • Commercial facilities — offices, shopping centers, schools, cultural institutions.
  • Industrial systems — production halls, warehouses, logistics complexes.
  • Hotel and wellness sector — hotels, fitness centers, swimming pools.
  • Public spaces — airports, stadiums, exhibition halls, transport hubs.

Product catalog

More information

Discover ZERN ENGINEERING’s full range of heat exchangers. Our product catalog provides detailed specifications, material options, and performance data to help you select the optimal solution for any application

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