Double Rotary Heat Exchanger Setup

A double rotor heat exchanger setup is the most energy‑efficient solution for ventilation systems operating in hot and humid conditions. By combining an enthalpy (sorption) rotor with a sensible rotor, the system delivers optimal control of both humidity and temperature, while significantly reducing energy consumption.

In many ventilation systems, especially in humid climates, outdoor air must be:

• Cooled
• Dehumidified
• Reheated to supply conditions

Traditional systems achieve this through mechanical cooling followed by reheating—an energy‑intensive process.

A double rotor setup replaces this with a more efficient approach:

• The enthalpy rotor pre‑cools and removes moisture from incoming outdoor air
• The cooling coil brings the humidity down to the required level
• The sensible rotor reheats the air using recovered energy

This integrated process allows cooling, dehumidification, and reheating to occur in a single system—using significantly less energy.

Double-rotor configurations are primarily used in regions with high temperatures and humidity, where latent loads dominate.

In these environments, ventilation air must be dried before entering the building to maintain indoor comfort and prevent condensation issues.

1. The enthalpy/adsorption rotor dehumidifies and cools the hot and humid outside air.

2. The cooling coil dehumidifies the outside air until the requested humidity level is reached.

3. The sensible rotor reheats the outside air to the required supply air temperature.

4. At the same time, the exhaust air is cooled, which increases the efficiency of the enthalpy/adsorption rotor.

The double-rotor concept is an energy-efficient solution for cooling and dehumidifying outdoor air for comfort ventilation applications. It utilizes highly efficient rotating heat exchangers with up to 90% humidity efficiency, eliminating the need for less or no reheating.