I need a detailed duct and airflow design for a tempering unit, specifically aimed at achieving optimal airflow. The deliverables should include: - 2D CAD drawings and 3D models - Exact dimensions and measurements - Placement of components Please ensure the design prioritizes accuracy and is suited for preparing official drawings. Let me know if additional information is required! Project Overview R.E.M. Services is developing a tempering unit to defrost 8.6 tonnes of frozen chicken from –18 °C to ≤ 5 °C surface temperature within 24 hours. The client wants on supply air grill across the 5800mm of the roof and one return air grill across the bottom of the cool room to ensure correct airflow is achieved. The system uses electric heater banks (40 kW total) to provide the required thermal energy, while a refrigeration system maintains controlled temperature and humidity throughout the defrost process. We have already selected the refrigeration unit, and the design must integrate with the existing evaporator coil. Existing Equipment Evaporator Coil Dimensions: 3315 mm (W) × 539 mm (D) × 1015 mm (H) Refrigeration Unit: Pre-selected condensing set compatible with the above coil details attached. Heater Bank: 40 kW, 415 V 3-phase, to be located in the supply section upstream of the evaporator Total Airflow: 3.0 m³/s (≈ 3 000 L/s) Design Objective Design the supply and return plenums and overall airflow arrangement around the fixed evaporator footprint, ensuring: Even air distribution over the evaporator and across the product zone Smooth airflow path from supply → product → return Accommodation of booster fans for both supply and return air to maintain consistent circulation and overcome system pressure losses Clean, serviceable geometry that suits food-grade environments Scope of Work for the Freelancer Supply Plenum Design Design a supply air plenum that evenly distributes heated air through the 3.315 m-wide, 1.015 m-high evaporator face. Incorporate a 40 kW heater bank upstream of the coil. Allow for the integration of a supply booster fan (centrifugal or inline type) to achieve approximately 3.0 m³/s system airflow. Please calculate if this will be enough. The supply air should discharge uniformly across the evaporator into the room, avoiding direct hot spots or short-circuiting. Include smooth internal transitions, access panels, and any internal baffles or perforated plates needed for flow equalisation. Return Plenum Design Design a return air plenum to capture air evenly from the room (preferably at low level) and return it to the AHU or evaporator intake side. Integrate a return air booster fan to assist circulation and balance the static pressure across the evaporator. The plenum should maintain uniform velocity and be sized to minimise turbulence and noise. General Requirements Layout must suit a room footprint of 4.5 m (W) × 5.8 m (L) × 2.3 m (H) with a roof height of 6 m for the AHU assembly. All plenums and transitions to have clean internal surfaces (hygienic food-grade design). Include sufficient service access for coil cleaning, heater maintenance, and fan isolation. Provide drain provisions and consider insulation thickness in final dimensions. Deliverables 2D Plan and Elevation Drawings (A4 or A3) showing the evaporator, heater bank, supply and return plenums, and booster fans. Airflow arrows and component callouts clearly indicated. Include major dimensions, transition shapes, and approximate clearances. Drawings should be fabrication-ready and suitable for coordination with the mechanical and structural layout. Notes The freelancer should propose duct and plenum geometry that achieves the design intent. The focus is on airflow uniformity, easy access, and hygienic construction. R.E.M. Services will confirm materials, insulation type, and exact fan models once drawings are approved.