Energy Exchange Rotary energy recovery wheels operate by exchanging energy from two opposing airstreams. Known as a heat wheel, it is a simple mechanical device that if designed and constructed properly can afford a high degree of energy recovery -- up to 90 percent. The building's exhaust air preconditions supply air. Heat recovery wheels are extremely efficient because they transfer total energy -- heat and moisture -- between two airstreams.

In summer the outside air is hot and wet.  The inside air is cool and dry.  The wheel rotates through the two airstreams and transfers the energy contained in the return air from the building to the supply air, which becomes cooler and dryer.  This cooler and dryer air is the supply air, which enters the cooling coils and lowers the need for cooling capacity.

In winter the opposite state occurs.  The outside air is cold and dry.  The inside air is warm and wet.  The wheel transfers the energy contained in the return air from the building to the supply air, which becomes warmer and wetter and lowers the need for heating capacity.  The desiccant coating on the wheel is the primary driving force of this transfer. 

 In winter the opposite state occurs. The Outside air is cold and dry the Inside air is warm and wet. The wheel again transfers the energy contained in the return air from the building to the supply air which becomes warmer and wetter lowering the need for heating in the building. In both cases the desiccant coating on the wheel is the primary driving force of this transfer.

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There are two reasons for wheel failures:

Mechanical: The wheel is not turning.

Thermodynamic: The media is not transferring energy.

With proper design, both types of failures can be eliminated. By engineering the rotor for a twenty-five-year minimum life, mechanical failures are reduced to near zero and maintenance is reduced to a simple biannual greasing of the bearings. Depending on the environment, proper filtering of the airstreams can extend media life to twenty years or more. Performance is dictated by the media substrate, flute size, wheel size, and rotational speed.

There are many combinations of these factors, each with advantages and disadvantages. For most applications, aluminum media with a width of 200 mm and a flute size of 12 flutes per inch provides excellent performance with a minimum of pressure drop. A desiccant coating based on a 4 Å or 3Å molecular sieve can provide equal sensible and latent recovery with a minimum of contaminant carryover. Total effectiveness of up to ninety percent is possible.

This wheel has loose media caused by a basic design fault.

The media is not securely held in place by the spokes and tension of the rim. As the wheel rotates the force of rotation causes the media to begin to wear on the spokes.

Our rim and spokes have slots and grooves which correspond to matching slots and grooves machined into the media.

This coupled with our unique rim tensioning system provides a wheel that is extremely strong. Note: here you can also see the "I" beam design of the spokes and the massive frame which keeps our rotor assembly from shifting.

This wheel was severely damaged when the seal was pulled into the media face by the rotational force of the wheel.

The seal can then do considerable damage to the
media face.

Our seals are held securely in place with machine screws. We don't use clips or rivets which can easily fail and allow the seal to damage the media face. Note how close we can position the seal to the media.

This is because our wheels can be made extremely flat and there is almost no deflection of the wheel caused by the airflow.

This wheel has had a rim break at the rim joint. This caused a catastrophic wheel failure.

Weak welds and formed steel components will not provide for the strength needed for a wheel operating continuously.

Our rims are designed as an box structure made of 2 pieces of extruded aluminum.

This design provides for both a lightweight and extremely strong rim. The rim connector seen here from the bottom, holds each rim firmly to the spokes.

This is a Regenerative Heat Corp. wheel. The media was manufactured from steel fibers similar to steel wool and coated with a desiccant. Through years of use the media has become clogged with dust and dirt and is no longer capable of transferring the proper amount of latent energy between the air streams.

This condition will diminish free airflow through the wheel. It may look like it's working but it's costing thousands in lost energy recovery.

A typical retrofit with a THERMOWHEELTM system will pay for itself in energy savings within 12 to 18 months. Start with a wheel designed by engineers who have repaired every type of wheel failure.

Retrofit your heat wheel with a THERMOWHEELTM.