Rotary Heat Exchangers

In a rotary heat exchanger, the heat from the exhaust air is picked up by the aluminum matrix and transferred to the supply air as the wheel turns.

Rotary Heat Exchangers

Exchanger Models

Heatex rotary heat exchangers provide very high sensible and latent efficiencies. Models with casing are fitted with seals for excellent airtightness and can be equipped with purge sectors to minimize the cross-contamination of exhaust air into the supply air. By adding coatings to the wheel, humidity transfer or increased corrosion protection is enhanced. We offer an extensive range of options regarding sizes, material, and drives to suit various applications and performance requirements. Select a model below for detailed information, suitable options and accessories.

Compare Models

Every Model has a clear advantage depending on its application. All of our rotary heat exchangers share the same high-efficiency matrix.
Model E offers one of the most compact casings on the market whereas Model EQ features a segmented wheel for easy onsite installation or replacement in narrow spaces. Both wheels are also available without casing. Model EN is primarily designed for residential applications.
To determine which Model suits your application project, please use our comparison table below.

Model E/O EQ/EV EN
Airflow capacity 200 – 90 000 Nm3/h (125 – 56 000 CFM) 2 000 – 190 000 Nm3/h (1 170 – 110 000 CFM) 50 – 2000 Nm3/h
(30 – 1 177 CFM)
Rotor design One piece Segmented One piece
Configuration Model E: With casing
Model O: Without casing
Model EQ: With casing
Model EV: Without casing
Without casing
Exchanger orientation Vertical or horizontal Vertical only Vertical or horizontal
Rotor diameter 500 – 2575 mm
(19.69″- 101.38″)
+50 mm (1.97″) with Casing
1600 – 3800 mm
(47.24″ – 149.61″)
200 – 500 mm
(7.87″ -19.7 “)

IAQ optimization

Rotary heat exchangers that are properly constructed, installed, and maintained, have almost zero transfer of particle-bound pollutants. To ensure the best performance and cleanest air possible, it’s essential to understand the basics and best practices.

Guide - Improving Indoor Air Quality
pollutant concentration graph
Balance Pressure Difference

The most important step to prevent exhaust air from mixing in with the supply airflow and reentering the building is the correct distribution of pressure between the separate airflows. Air pressure should always be higher on the supply side compared to the exhaust side. This minimizes any leakage from the exhaust air into the fresh supply air. This applies not only to the heat recovery unit itself but to the building as a whole and most of the parts constituting the ventilation system (e.g., ducting and recirculation dampers).

The combination of higher pressure in the exhaust airflow versus the supply airflow affects the rotary heat exchanger by disabling the purge sector, which leads to a carryover effect through the matrix. Turning off the rotor will only stop the carryover, but leakage through the sealings might still appear.

Different fan positioning has different advantages. To minimize EATR (Exhaust Air Transfer Ratio) and OACF (Outdoor correction factor) values, combining two pulling fans for both the supply and the exhaust airflows has proven to be a favorable solution. However, it leads to negative pressure on both sides. Yet to compensate, slightly increase pressure on the supply side.

fan positioning

Add a Purge Sector & Sealing

The purge sector is optimized to reduce carryover or EATR. It will stop the inlet of exhaust air in the small area right before the airflows switch, thus preventing exhaust air from getting trapped into the matrix. A small amount of the supply air is used to blow out the minor amount of exhaust air that might have been trapped to ensure a fresh and clean supply of air.

Heatex does not support lowering the flow rate to reduce the leakage rate because the flow rate induces a pressure drop required by the purge sector to function. We recommend therefore running the rotor at a nominal (or, if possible) higher flow rate.

Note, Heatex also provides modular purge sectors to be assembled at a later stage.

Also, adding an optional Heatex “Special Seal” made of polymer on the middle beam and across the purge sector reduces leakage through OACF by 50% compared to the standard seal.

purge sector and sealing

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