Retrofit Overview Instructions
At Thermotech we have an extensive database of all manufacturer's products. All the components required are shipped direct to replace your existing wheel with a THERMOWHEELTM. The old wheel is removed and any structural changes required to support the new installation are performed.
Then the rotor and supporting hub and bearing assembly are installed.
Next the new media is loaded and each piece is tensioned with the unique rim tensioning system. After the new wheel is in place. The seals are set and the motor, control panel and sensors are installed as required.
Below is a step by step guide through the process.
PHASE: REMOVAL, FRAME INSTALLATION, BEARING INSTALL, SPOKE INSTALLATION, ROTOR ASSEMBLY, SEAL INSTALLATION, MEDIA INSTALLATION
MEDIA: MEDIA SECTIONS, COMPLETION OF MEDIA INSTALLATION, RIM TENSIONING,
ROTORS: COMPLETING THE ROTOR, DRIVE INSTALLATION, CONTROL INSTALLATION
First remove the existing rotor, media, hub, spokes and rim.
Prepare the old components for removal from the site.
In many retrofits creating a sound structure to support the wheel is the key to a successful job.
Install new supports as needed to keep the bearing and rotor assembly held firmly in place.
The structural supports and frame are installed to minimize wheel deflection and the safing ring is installed to prepare for seal installation.
Here you can see the hub and bearing assembly positioned in the frame.
You can also see the prepared surfaces that the seal assembly will attach to.
The hub and bearing assembly differ depending on the type on unit being replaced.
As you can see easy access is provided to lube fittings on the bearings. Once the structure is complete and the hub is in place the spokes can be installed.
Each spoke must be precisely positioned on the hub. The THERMOWHEEL hub has keys which align each spoke in place.
Once the spoke is in place it is measured for proper position and torqued securely to the hub. Note the groves in the spokes. Each groove will correspond to grooves machined in the media. The media will be positioned by these grooves to provide an extremely flat and strong wheel assembly.
The rotor assembly is now completed and ready to receive the media.
Note the seals have been installed and act as guides as the media is positioned in the rotor. Typically each section of media is shaped like a piece of pie and are positioned in place one at a time.
The seals are bolted securely to a solid steel safing ring.
The seals are of a labyrinth design comprised of an extruded aluminum mounting plate and an extruded rubber seal.
Note: The slot in the aluminum mounting plate provides for accurate adjustment of the seal after installation.
Each pie section is carefully positioned in the rotor.
Once the sections are in place the rim is mounted to hold the media with minimal tension. After all the media sections are in place, the rims will be gradually tensioned individually to provide a very flat and round wheel surface.
As the media is loaded you will note that each section of the media is installed so that the rotor stays balanced.
Because of the unique rim tensioning system the rims can be tensioned separately.
Here you can see 2 sections loaded.
Note that they are opposing each other. This keeps the rotor balanced during media installation. By doing this stress is eliminated on the spokes providing for a flatter stronger wheel.
As each section of media is installed secondary spokes are positioned in place to limit any shifting of the media.
 
The media is then positioned so that it is within + or - 1/32"of overall flatness. Each rim is given enough tension so that the media can be moved into position for the desired flatness.
Rim tensioning and getting a flat wheel are interrelated.
With the exclusive, THERMOWHEELTM.* tensioning system, tension can gradually be applied to each section of the media independently. Here you can see how the rim tension bolts act to pull the rims together so that there is proper tension on each section.
Here the completed rotor is seen as the rim tensioning is in progress.
The media is positioned so that it is within + or - 1/32" of overall flatness. Each rim is tourqued in place and the secondary spokes are permanently installed. Now that the rotor is complete, move on to the motor drive and belts.
The motor drive is mounted on a hinged plate which allows the motor to move vertically.
It is the weight of the motor that tensions the twin "V" belts. This configuration is foolproof.
There is no need for springs or adjustments. Let gravity do the work. Note how the motor is very accessible. A sealed compartment is provided for the drive. The drive is a variable frequency design that provides the full range of rpm needed.
The controls are usually mounted on the outside of the air-handler.
Depending on the type of unit, Thermotech can provide sensors in all 4 air-streams and interface to any existing control system. Thermotech can provide the right control for any facility. After the controls are installed the unit is operated at all specified speed settings and the controls are set so that the proper supply air temperature is met. That does it, the installation is complete.
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