The need to address sustainability in the built environment is being accelerated by external concerns. Some of these are environmental and resource issues, rising energy prices, climate change, indoor environmental quality, international pressure, energy security, and natural disasters that seem to be happening more frequently than ever before. Sustainability focuses on the distant future. Resiliency focuses more on the present, e.g. How do we keep our buildings functioning during floods, long power outages, or protect building occupants from smoke and odors during wildfires?
There is a new chapter on Climate Change in ASHRAE’s 2021 Handbook of Fundamentals. I was pleased to be a member of the International Task Force that developed that chapter. Historically, designers and planners assumed a stable climate, and heating and cooling designs were based on statistics calculated from past weather data, typically for a recent 30 year period. We are now experiencing major global changes in climate at rates 10 times greater than seen since the end of the last ice age 20,000 years ago – over decades instead of centuries or millennia.
Relative to indoor air quality (IAQ), a recent survey conducted by Honeywell Building Technologies between March and May 2021 revealed the challenges, concerns and priorities of facility managers. Globally, six in 10 respondents, for example, are now more likely to invest in technologies that optimize IAQ and other aspects of occupant health and safety, while 63% are more willing than pre-COVID-19 to implement smart building solutions that help drive efficiency or support sustainability.
Climate and Weather
Chronic changes in climate increase the stress or demand on buildings and systems. Acute events, e.g., heat waves/domes, sustained high night-time temperature and humidity, extreme rainfall, drought, wildfires, etc. affect near-term operational performance, occupant comfort and health, long-term energy efficiency, and productivity.
Mitigation reduces the impact of buildings and systems on the environment. It is relatively specific. Adaptation is the process of adjustment to actual or expected climate that seeks to moderate or avoid harm, and exploit beneficial opportunities. Adaptation has an interconnected relationship with mitigation and resilience.
Mitigating Climate Change
- Periodic building audits and retro-commissioning need to be done frequently.
- Proper commissioning of retro-fitted systems in existing buildings, and all systems in new buildings must be done. It has been found that commissioning in new buildings often pays for itself within 2 years.
- Most buildings will lose up to 30% of their efficiency in the first 3 years of operation.
Existing building retrofits need to increase in frequency and achieve greater energy savings.
- Deep energy retrofits, i.e., those that provide at least 40% energy savings and require a whole building approach such as chiller or boiler replacements are required to achieve global climate change mitigation goals.
Adapting to Climate Change (and Pandemics)
Depending on the usage of a building and the criticality of each system, building components and systems are designed to function under some predefined extreme environmental or usage conditions. During these events, systems must maintain operational performance. System redundancy or modularization that can handle extremes must be considered in both new design and retro-fits, especially for critical facilities.
What do we do (or not do)?
- The planning framework for the future ASHRAE Guideline 44P, Protecting Building Occupants from Smoke during Wildfire and Prescribed Burn Events, expected to be out for review later this year, is an important work-in-process. It includes building operation and maintenance (O&M) procedures that should be done on a regular basis. Readers will be familiar with most of these procedures; the question is are they being done?
These include many items that should be looked at in an energy audit, e.g., proper filters that are changed on a regular basis and properly installed, proper operation and maintenance, proper system airflows, proper operation of economizers and economizer control, air cleaners either in the HVAC systems and/or portable to mention only a few items that need to be done on a continual basis. Oh yes, did I mention the word “proper”? The preliminary document can be seen at https://tinyurl.com/yxyuqh72.
- Do not place major mechanical and electrical rooms in basement or sub-basement areas as is so often done, especially in commercial buildings so valuable rental space is not lost.
- Do not place all major mechanical and electrical equipment on the same floor, or in the same area.
- If standby generator systems are being used, be aware of how much fuel might be required if a power outage lasts for more than 2-3 days. Also be aware of how that fuel will get there if the roads are impassable due to flooding or other events.
- To reduce the amount of outside air that might be required in some of these acute conditions, look at air cleaning technologies that can be used to do that. Also be aware of air cleaning technologies that can inactivate viruses. See blog of 08/27/20, “IAQ & COVID – Moving from What Now to What’s Next”.
- Be aware that pre-cooling a building in the evening hours will not be available when summer night-time temperatures and humidities are almost as high as the daytime temperatures. If that temperature does not go below 70F (21C) and the humidity is high, which is happening more often even in more northern climates like MI where I live, pre-cooling to minimize the stress on the cooling systems will not be an option.
For additional information read the article in the September 2021 issue of Building Operating Management entitled Sustainable and Resilient: The Future of Buildings.