Supermarket HVAC Design – Rooftop Package Units (ASHRAE-Based) Supermarkets may look like open spaces, but from an HVAC standpoint, they are among the most airflow-sensitive commercial environments. In a recent project, I handled the full air distribution design for a supermarket served by rooftop package units, fully aligned with ASHRAE 62.1, ASHRAE 55, ASHRAE HVAC Applications, IMC, and SMACNA. 🔹 Supply Air • Air supplied along aisles, not toward shelves or open refrigerated displays • Linear/slot diffusers mounted on main ducts • Controlled velocity, throw, and NC to avoid drafts and stratification 🔹 Return Air • High-level returns, strategically located • Separated from supply to prevent short-circuiting • Promotes smooth airflow across the sales floor and removes heat from lighting and occupants ❄️ Open Refrigerated Displays • No direct supply or nearby returns • Prevents cold air curtain disruption, excess refrigeration load, condensation, and energy loss • HVAC ...
Types of Chiller Evaporators and How They Work In the HVAC and refrigeration field, evaporators play a vital role in producing cold air or chilled water. Common types of evaporators: ▪️Shell-and-Tube Evaporator - Primary function: Refrigerant flows through the inner tubes while the secondary fluid (water or brine) flows in the shell, transferring heat from the secondary fluid to the refrigerant. - Advantages: High cooling capacity, good performance at high pressures, suited for large-capacity applications. - Disadvantages: Relatively large size, higher construction and maintenance costs, high volumetric mass. - Applications: Large-capacity chillers and industries with broad cooling demands. ▪️Plate Evaporator - Primary function: Cold refrigerant exchanges heat with the secondary fluid by flowing across a series of plates with extensive contact surfaces. - Advantages: Very high heat transfer per contact area, relatively small and light, reduced weight and footprint. - Disadvantage...