Course Description

Let us begin with a fundamental premise. Active HVAC systems-chillers, boilers, VAV boxes, and fan coil units-consume between 40 and 50 percent of a commercial building's total energy. In many office buildings, that fraction is even higher. This makes HVAC the single largest target for energy reduction. The global push for net-zero operational carbon, reinforced by legislation like the EU Energy Performance of Buildings Directive and the US Inflation Reduction Act, requires designers to first minimize thermal loads via passive means before adding any active mechanical equipment. Many of the alternatives we will discuss are not new. They are revivals of pre-industrial building physics-windcatchers, thermal mass, earth cooling-but now adapted with modern materials, sensors, and controls.

What you'll learn in this course?

• Learners will evaluate the thermal performance of building envelopes, including insulation strategies, thermal bridging mitigation, and airtightness, as the first alternative to mechanical conditioning.

• Learners will design and size passive solar heating systems using glazing orientation, thermal mass, and shading strategies for different climate zones.

• Learners will apply natural ventilation principles, including stack effect, cross-ventilation, and wind-driven strategies, to reduce or eliminate mechanical cooling.

• Learners will select appropriate radiant cooling and heating systems, including slab cooling, chilled beams, and radiant panels, as low-exergy alternatives to forced air systems.

• Learners will implement earth coupling techniques such as earth-air heat exchangers and basement-assisted conditioning for pre-treatment of ventilation air.

• Learners will specify evaporative cooling technologies, including direct, indirect, and two-stage systems, for arid and semi-arid climates.

• Learners will integrate dedicated outdoor air systems with heat recovery ventilators or energy recovery ventilators as the minimal-active backup to passive strategies.

• Learners will analyze whole-building trade-offs between passive and active systems using energy modeling and life-cycle cost analysis.

• Learners will understand the hierarchy of HVAC design: reduce load with envelope, then apply passive conditioning, then low-energy active systems, and finally conventional active only for peak extremes.

• Active HVAC systems, including chillers, boilers, VAV boxes, and fan coil units, consume approximately 40-50% of a commercial building’s total energy, making them the single largest target for energy reduction. Wiscademy | Alternatives to Active HVAC Systems 2

Prerequisites

• Basic engineering knowledge and familiarity with HVAC or industrial utility systems