Rotor media:
The rotor media must be provided in segments. Each media segment must be machined to fit in between a primary and secondary spoke and a guiding flange of the outside rim. Each segment of media must be compressed independently of all other segments during the assembly process without causing any angular deformation and resulting misfits between the spokes and media parts, and to provide a wheel with a flatness of +/ - 1/32".
No adhesives or silicone shall be necessary to secure the media in place in order to allow for future replacement in the event of damage to a section.The heat transfer media shall be the industry standard of 200mm in width. Non-standard widths shall be unacceptable.
The rotor system must be able to accommodate the following acceptable media types for applications requiring equal sensible and latent energy recovery.
- Molecular Sieve coated aluminum foil.
- Inorganic fiber for corrosive environment.

For applications requiring sensible energy recovery only the rotor system must be able to accommodate the following acceptable media types.
- Epoxy coated aluminum foil for sensible low temperature heat transfer only.
- Stainless steel foil for corrosive and/or high temperature applications.
- Inorganic fiber for corrosive and/or high temperature applications.

The heat transfer media shall be corrugated with a high surface area per volume and laminar flow to allow dry particles up to 900 microns to pass freely through the media to assure that no fouling occurs on the internal heat transfer surface.

The media shall be cleanable with a brush, a vacuum or compressed air without damaging the media or the latent energy recovery. In severe exhaust applications, the media shall be cleanable with 2300 psi water pressure without causing damage to the media or latent energy recovery. Aluminum media shall have an anti corrosion epoxy edge coating.

Seals:
The seals shall be of a maintenance free "non-contact" type to eliminate wear, excessive drag and resulting added horse power required for the motor drive system, while still being capable of resisting high pressure differences. The seals shall be made in 2 sections. An extruded rubber seal of a 4-pass labyrinth "turbine" type design minimum ¾" thick and an extruded aluminum strip with adjustment slots for fastening bolts to the casing frame. The seal system must be able to withstand a pressure difference up to 12 in.wc. without deflecting causing excessive air leakage. The seals shall be adjustable and set to within 1/32" of the rotor surface.

Drive System:
The drive must be gravity tensioned and shall use 2 standard "B" section V- belts to drive the rotor. The speed reducer must be grease lubricated, maintenance free with a flexible Love-Joy input coupling for easy motor separation and for absorption of any shock or vibration. The drive system shall be easily accessible and visible for inspection and maintenance and have a minimum life expectancy of 50,000 hours.

Speed Control:
The speed control system shall be a variable frequency inverter operating a standard inverter rated AC motor, capable of operating the rotor from 1/4 rpm to 20 rpm or to whatever is required for the type of media used. It shall integrate with the temperature control system to provide the required supply air temperature.

Temperature controller:
The temperature controller shall monitor entering and leaving temperatures for the exhaust and supply air. Adjustable set points shall be for the heating mode discharge temperature, summer/winter change over and for wheel frost control.
For multiple rotors in a common air stream each rotor shall provide temperature outputs to the controller in order to get an accurate average discharge temperature.

Owner demonstration:
The proper operation of the controls, drive system, rotor deflection, seal adjustments, purge adjustments and required maintenance procedure shall be demonstrated to the owner upon start up.

Maintenance:
The entire rotor and wheel assembly shall require only limited maintenance of biannual greasing of the main bearings and inspection of the drive system.

Warranty:
A standard 3 year material and labor warranty covering all materials supplied and installed.
Optional 7 year extended warranty shall be available with an annual service contract.

Casing Frame Structure:
The structural frame or casing can be designed and manufactured in one, two or more sections to provide a rigid structure, when completely field assembled, capable of supporting the rotor. It shall be capable of being supported at each end only with no additional support under the center when installed for horizontal airflow applications. For vertical airflow applications one additional bottom center support shall be required.
When completely assembled and installed the casing shall allow for a maximum acceptable rotor deflection of 1/32", as measured at the outer radius, during maximum rated airflow condition, and thereby eliminating excessive air seal bypass and/or additional seal drag. All sections shall be clearly marked for easy field installation. All structural steel shall be painted with red oxide primer.

Sheet metal and air seal mounting surfaces:
All sheet metal shall be reinforced as required to provide a solid mounting surface of the peripheral and radial seals in order to maintain a minimum of 3/4" fixed distance between the rotor surface and any sheet metal or steel parts. All four halves, air entry and exit areas, of the rotor surface shall be sealed off to force the air through the heat transfer media minimizing cross leakage and by-pass. One half may be substituted with a side seal that blocks the air leakage at the outer end between the rim and the stationary casing wall in order to provide full access to one half of the wheel. This type of seal shall only be acceptable when the outer rim forms a smooth and flat surface.
There shall be no special requirement to provide any casing side access for future rotor removal and/or service. All such service work shall be possible to perform from inside the duct at the face of the rotor casing.

Purge Section:
A purge section shall be provided to eliminate transfer of exhaust air into the supply air, and shall be field adjustable to provide the desired purge air volume.

Hub and Bearings:
External bearings shall be used and sized to provide a minimum L-10 life of 219,000 hours of operation and shall be changeable without a complete disassembly of the rotor.
Provisions shall be made for grease fittings that are easily accessible.
Shaft journals shall be machined to proper tolerance as specified by the bearing manufacturer to avoid any problems with bearing setscrews loosening and premature shaft wear. Shaft shall be machined as to provide a shoulder against the bearings for a positive locked position to eliminate any lateral movement of the rotor due to set screw failure or shaft wear.

Spokes:
The spokes shall be made of extruded aluminum with an "I" beam shape to limit deflection of the rotor to 1/32" for the maximum rated airflow. Spokes shall consist of a primary and a secondary spoke to allow for easy field assembly. Surfaces to be serrated for increased friction and air turbulence across the seals.

Rims:
Rims shall be made of 2 extruded aluminum sections. 1 outer rim with grooves for the twin "V' belts, and one inner rim with guide flanges for securing the media. The 2 sections shall be welded together to form a tubular structure for improved strength in order to maintain an accurate radius and rotor roundness during the installation process.

Rim Joint:
The rim joint shall connect the spoke ends and the rim ends together in such a way that the heat transfer media can be installed under field conditions without any media deformation or misfits causing future problems. The rim joints shall provide a gradual compression of each section by independently applying increased tension of the rim bolts without the use of any special tools or devices.