At Mead and Hunt, people are at the heart of our values. We are empowered to take care of our employees, clients, and the communities where we live and work. Our values are synergistic with LEED v5’s emphasis on the well-being of people.
As we continue the LEED v5 blog series, I invite you to explore the “human side” of building design and understand the new Quality of Life impact area, which accounts for 25% of LEED v5 credits. While quality of life is a broad category, this blog will focus on mechanical engineering contributions to improve air quality and resiliency.
New Air Quality Language in Prerequisites and Credits
The credits that are new or contain substantial changes discussed in this article are:
- Updated Fundamental Air Quality prerequisite criteria
- Air Quality Testing and Monitoring
- Enhanced Air Quality
- Resilient Spaces
Each of these credits leverages the developing science since LEED v4 was published of air quality and design resiliency as a response to extreme events from climate change.
Air Quality: Why Should You Care?
We are bombarded by daily outdoor air troubles, including vehicle exhaust, regional pollution, odors from neighbors, and, with increasing frequency, wildfire smoke. However, pollution generated within buildings is a less-known concept. Pollution sources include people breathing, cooking, and cleaning products and printers. LEED v5 sets standards and recommendations to improve projects’ indoor and outdoor air quality.
A LEED v5-rated building will provide respite related to these modern issues by requiring an outdoor air quality investigation and minimum MERV 13 particle filtration on outdoor ventilation and recirculated building air. This filtration is widely available, cost-effective, and essentially eliminates Legionella, flu/sneeze particles, auto emissions, and dust from the air.
Air Quality Monitoring
LEED v5 points are available for air quality monitoring. These monitoring systems can be stand-alone or integrated into the buildings’ mechanical ventilation. Integrating air quality monitoring into a building’s mechanical ventilation control system ensures that mechanical ventilation can follow the “goldilocks” principle. Increasing ventilation when spaces are occupied to ensure good air quality but also decreasing ventilation during times of non-occupancy to reduce operational energy costs and building carbon footprint.
LEEDv5 and Resiliency
LEEDv5 requires a climate resilience assessment to ensure that the owner and design team are aware of observed and projected future natural hazards and awards points for the team to tailor design based on the resilience assessment results. LEEDv5 awards multiple mechanical design strategies tying into resiliency including HVAC management modes for poor outdoor air quality (wildfires), management modes for respiratory diseases, power outage (shelter in place) thermal safety and operable windows.
A Mechanical Design Example for the new LEEDv5 Resilient Spaces Credit
One simple way that our projects are already addressing the topic of resiliency and the changing climate is by using observed gradual temperature change when sizing heating, cooling, and ventilation systems. When desirable by an owner, mechanical engineers reference both traditional (historical), recently observed, and predicted outdoor temperatures to ensure buildings can maintain thermally comfortable setpoints into the future.
This graph shows the story of how summer outdoor air temperature is used to size mechanical cooling equipment for the Traverse City Airport mechanical systems replacement project. While the recent 97°F high observed temperature was only observed for a short time, lengthy time periods that are warmer than the traditional design temperature of 86°F have been observed annually in recent years. To allow the airport to remain comfortable for travelers and staff during the summer, a 93°F design temperature was selected.
More in the LEED v5 series:
This is Part III in our LEED v5 series. So far, Rebecca Aarons-Snydor has given an overview and laid out the LEED v5 timeline and Victoria Herrero dove into decarbonization in the new version. Stay tuned for our next blog where we dive into the topic of ecosystems.
