Our customer in the medical device manufacturing industry required a new skid duct heater system with several application requirements that included:

• 4KW heater run at 240 volts – Duct Heater
• Air pressure switch for heater – Cleveland DFS-221-112
• Control panel – Custom Designed Tempco Control Panel
• Blower – McMaster-Carr number 1963K13
• Heater and blower differentiating voltages with a step down transformer
• Maximum footprint of entire system: 26” long x 22” wide x 48” tall

There were several challenges Tempco faced when engineering this system:

• Challenge: Design the duct heater and blower combination to fit the 26” x 22” floor footprint while making the duct heater field service replaceable and taking into account that a pressure switch was required at the end of the duct heater.
• Resolution: A flange heater “cartridge” was used inside a main duct housing assembly to address the serviceability issue. The main duct flange and the terminal housing were both extended to make room for both the “cartridge” and the pressure switch, so that any service issue could be addressed without interfering with the other. 

• Challenge: Design the control panel (approx. 24” x 24” x 10”) and transformer (approx. 10.5” x 9” x 17”, #100 weight) to fit together in the volume footprint outlined above while maintaining heater serviceability.
• Resolution: Due to the footprint constraints, particular attention was paid to each portion of the complete system in order to maintain serviceability of the heater “cartridge” assembly. The limiting issues were the rigidity (lack of “freeform” flexibility) of the wiring conduit and close proximity of the control box to the duct’s terminal housing. This arrangement led to significant wiring routing difficulties which were resolved with conduit ports placed specifically to allow the control panel and transformer to be ideally placed.

• Challenge: Due to the small size of the skid (26” x 22”) and the fact that the majority of the system was consumed by the heater and blower combination, we could not design it to be transported with a forklift the way we normally would.
• Resolution: Tempco reinforced the framework that held the control panel and transformer in place to use as a lifting point for the system.  Eyelets capable of holding the weight of the system were placed in the uprights of the framework in order to use a lift to transfer/locate the system.