HVAC: Balancing ventilation and energy use

There are many factors to consider when choosing and designing HVAC systems for buildings. Those decisions ultimately influence how energy-efficient the building is. The major factors to optimize for energy efficiency are ventilation, zone control, heat recovery and operations.

HVAC equipment exists to fulfill two goals: ventilation and comfort conditioning. To accomplish those two goals, a certain amount of energy has to be expended, but the goal of an efficient HVAC system is to minimize the energy input to do it. Ventilation in hot, humid and cold climates is one of the largest loads on HVAC systems.

The integration of high-performance HVAC design strategies can do as much to make systems energy-efficient as specifying high energy efficiency ratings.

Well-designed heating, cooling and ventilation energy-recovery systems are able to maintain a building’s proper temperature and air quality while minimizing energy loss. The type of system to use varies depending on the application, but the most common is ventilation energy recovery.

Learning Objectives

• Review the codes and standards, such as ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings, in the design of energy-efficient HVAC systems.
• Understand HVAC design strategies, and learn about options like precision cooling to address challenging environments.
• Learn how heat recovery can reduce HVAC loads and energy.
• Review examples and options for balancing ventilation and energy use.