Signicast Texas | Dry Tunnel AHU Addition
Dynamic provided the HVAC design for a small, but critical final dry tunnel in the manufacturing process for Signicast Corporation. As part of the manufacturing process, Signicast creates wax molds that are formed and dipped into a slurry mix mulitple times which creates a shell of a product that is set to be cast from metal. Throughout the process, tight temperature and humidity requirements are required as the molds are created, dipped, and dried in a multi-step process. As part of the last process prior to creating the mold, the product enters the final dry tunnel where it is cured prior to the production of metal parts and pieces for production.
The final dry tunnel was designed with a 9,000 CFM air handling unit to maintain a constant 75°F at 20% relative humidity. The final dry tunnel was an existing tunnel, which previously used multiple rooftop units to attempt to maintain the tunnel conditions, which proved to be unacceptable causing the molds to take longer to dry or crack.
Since space within the existing manufacturing facility was difficult to come by, a new mezzanine was created to house the new air handling unit with a cargo care unit. The cargo care unit is provided with a desiccant wheel and bypass to dehumidify the process air requiring gas heat to activate the air. Additionally, an air cooled chiller designed in a variable primary flow to supply chilled water downstream of the desiccant wheel to supply air at the appropriate temperature. Since temperature control is extremely critical, the cooling coil was provided with a pumped coil for precise discharge air temperature control.