Significance of 'Energy Recovery Wheel' in HVAC !

Energy Recovery Wheels (HRWs)

The Energy Recovery Wheel, which recovers total energy (sensible as well as latent), assists in meeting all the requirements of Indoor Air Quality (IAQ), humidity control and energy saving.

DRI offers the Highest Recovery Enthalpy Wheels in the world (Aluminum substrate coated with a choice of desiccants).

Incorporation of Heat Wheels into the air-conditioning system means more outdoor air at lower energy cost (reduced chiller load).

Energy Recovery Wheels also known in the industry as Energy Conservation Wheels, Energy Recovery Wheels, Enthalpy Wheels, Sensible Wheels, Hygroscopic Wheels, Condensation Wheels or Sorption Wheels. These air-to-air Heat Exchangers can recover both sensible (Heat) and latent (Moisture) energy but may use different technologies and offer different efficiencies.

How Does the Wheel Work?

In a typical installation, the wheel is positioned in an Air Handling Unit so that it is divided into two half moon sections.

Stale exhaust air is drawn through one half and outdoor air through the other in a counter flow pattern. At the same time, the wheel is rotated. Sensible heat is transferred as the metallic substrate picks up and stores heat from the warmer air stream and gives it up to the cooler one.

Latent heat is transferred as the desiccant coating on the metallic substrate adsorbs moisture from the air stream that has the higher humidity ratio and releases the moisture into the air stream that has the lower humidity ratio.

Operating Principle

Latent heat is transferred as the synthesized metallic substrate condenses moisture from the air stream that has the higher humidity ratio through adsorption (with a simultaneous release of heat) and releases the moisture through evaporation (and heat pick-up) into the air stream that has the lower humidity ratio.

Benefits of Energy Recovery Wheels

1. Pre-conditions incoming fresh air.
2. Easily integrated/retrofitted into new/existing ventilation systems.
3. Delivers fresh air throughout the year at conditions very near inside conditions.
4. Helps to meet ventilation standard without raising energy cost.
5. Maintains humidity conditions at no additional cost.
6. Allows reduction in system capacity by 30 to 65%.