Engineers’ daily challenges include calculations for outside air, supply air, and return or exhaust air flows — all while balancing mandated code requirements with owners’ expectations for performance, equipment first-cost, and future energy costs. This often involves difficult trade-offs that require critical comparison and careful analysis. These are not simple arithmetic formulas. Clearly, increasing OA airflow — highly valued for comfort and safety — could result in disastrous energy impacts. So, what is the “right” amount of outside air? How do we meet ventilation codes and standards with an HVAC system that is genuinely cost-effective and energy-efficient?
The SGJJR design team addressed these questions for an 80,000-sq-ft medical office building located in Hattiesburg, MS. Given the limited budget, the HVAC system was not complex or flashy, and the design team was challenged to find innovative ways to design a cost-effective system with a low operation cost.