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The Covid-19 pandemic has increased pressures for companies to ensure workspaces are better ventilated. However, eco-friendly design guidelines call for ensuring that energy heating or cooling such spaces is not wasted. In the second instalment of this two-part article series by ASHRAE we will look at how it is possible to answer both health and climate needs.
So how do we optimise to benefit both health and climate?
Give your buildings a tune-up: “Commissioning” is the process of making sure your building is performing the way it’s designed. I liken this to giving your car a tune-up. Everyone with a car knows that car performance slips over time. The same happens with buildings. We have design standards but not performance standards, and I guarantee your building is not performing the way it did on the day it opened, or even last year. The good news is that giving your building a tune-up improves indoor air quality and saves energy and money. The process involves simple things like system cleaning, performance checks, leak checks, evaluation of wear-and-tear as well as general maintenance. Lawrence Berkeley National Laboratory estimates the cost to do this at USD0.26 to USD0.82 per square foot, but, with energy savings of 5% to 14%, this has an ROI of less than two years!
Maximise outdoor air: Increased ventilation is one of the best strategies for reducing infectious disease transmission in buildings. It also comes with those cognitive function benefits and is associated with reduced worker absenteeism. Your employees will be less sick and perform better. It’s a no-brainer from a business decision-making standpoint. Adding heat-energy-recovery ventilation and heat-recovery ventilation – which recapture the energy and heat in air before it is exhausted from a building – should become commonplace.
Upgrade your filters: The filters in your building are most likely MERV-8 filters, which are designed to protect equipment and capture about 20% of airborne particles. MERV-13 filters are designed to protect people and should be the new minimum, as the U.S. government just mandated for all federal buildings, because they capture 80% to 90% of particles and are made with a low-pressure drop, meaning your HVAC fans won’t have to work too hard to push air through them and you won’t pay a significant energy penalty.
Deploy a real-time indoor air quality monitoring network: This is key because it is the path to understanding how to optimise both health and energy in a building. Currently we are flying blind when it comes to building performance. Is outdoor air pollution causing a problem? Are you hitting these new ventilation targets? Confident that the air quality in your building is “safe”? (Confident enough to share this data with employees?). Advances in new lower-cost, smart building sensor platforms are changing the game quickly, allowing us to verify the performance of indoor spaces and do things like demand-control ventilation, the process of adjusting airflow in a building based on occupancy using CO2. (Humans are the main source of CO2 indoors, so as we enter a room, the CO2 goes up. That means the ventilation rate should go up, too. But when we leave, we shouldn’t waste energy dumping loads of conditioned air into empty conference rooms.)
Work to electrify everything in your buildings: As the country phases out coal-fired power plants, it’s clearing the air and revealing that on-site fossil fuel combustion in buildings is an important source of air pollutant emissions, including greenhouse gases. Converting to things like air-source and ground-source heat pumps, which use electricity for heating and cooling instead of oil or gas, allow buildings to capitalise on all that renewable energy planned for our electrical grid.
Use energy-efficient systems in buildings: There’s a catch to the previous advice. Currently, electricity use is highest in summer due to air-conditioning. But our latest research showed that if all buildings convert to all-electric, we will shift to peak use in winter. (We call this ‘The Falcon Curve because the plot of monthly energy use looks like a falcon with its wings up.) To flatten the curve, we must reduce energy demand in buildings as we electrify them.
Beyond the strategies already mentioned, there are others like exploring energy storage for peak-shaving (The Bank of America Tower at 1 Bryant Park in New York City uses a giant ice cube in the basement as a thermal battery!), using phase-change materials, and doing the basics like adding solar panels. The big picture is that there are a lot of existing technologies on the market, ready to go. Just as it isn’t acceptable to have a green building where people get sick inside, it doesn’t make sense to have a building with good indoor air quality that nevertheless damages our health by contributing to outdoor air pollution. We can and must have both.
Can it actually be done? Look no further than JPMorgan Chase’s new headquarters in midtown Manhattan, designed by Norman Foster, with (full disclosure) my team advising on healthy buildings strategies. It’s an all-electric tower, sourced with renewable energy, with double the minimum ventilation rate, MERV-13 filters, and a real-time air quality monitoring system. If you’re a company or developer planning a new building and failing to consider such features or unwilling to retrofit your existing buildings, you might not be able to attract capital or talent if you don’t consider climate or attract tenants or talent if you don’t consider health. You might thus be sitting on a stranded asset in the not-too-distant future.
Expectations have changed. Corporate buildings — whether executive offices, call centres, factories, or retail and hospitality venues — must be both healthy and green, safe and smart.
