ASHRAE Epidemic Task Force releases updated Building Readiness Guide
ATLANTA, Georgia, 02 February 2021: With the performance of many HVAC systems in buildings still being evaluated, the ASHRAE Epidemic Task Force has updated its reopening guidance for HVAC systems to help mitigate the transmission of SARS-CoV-2, ASHRAE said through a Press release.
“The Building Readiness Guide includes additional information and clarifications to assist designers and commissioning providers in performing pre- or post-occupancy flush calculations to reduce the time and energy to clear spaces of contaminants between occupancy periods,” said Wade Conlan, Lead, ASHRAE Epidemic Task Force Building Readiness team. “New information includes the theory behind the use of equivalent outdoor air supply, method for calculating the performance of filters and air cleaners in series, and filter droplet nuclei efficiency that help evaluate the systems’ ability to flush the building.”
According to ASHRAE, major updates to the building readiness guidance include the following:
- Pre- or post-flushing strategy methodology: The strategy has been updated to include the use of filter droplet nuclei efficiency, which is the overall efficiency of filter, based on viable virus particle sizes in the air, to assist in determining the impact of the filter on the recirculated air on the equivalent outdoor air. This allows the filter efficiency as a function of particle size, using ASHRAE Standard 52.2 test results, to be estimated based on the expected size distribution of virus-containing particles in the air. This calculation is currently based on Influenza A data and will be updated as peer-reviewed research becomes available for the distribution of particle sizes that contain a viable SARS-CoV-2 virus. Additionally, a chart has been added to help determine the time to achieve 90%, 95% or 99% contaminant reduction, if the equivalent outdoor air changes per hour is known.
- Flushing time calculator: There is now a link to a view-only Google Sheet that can be downloaded for use, to help determine the available equivalent outdoor air changes and time to perform the flush. This sheet is based on a typical mixed AHU with filters, cooling coil, with potential for in-AHU air cleaner (UVC is noted in the example), and in-room air cleaning devices. Provided efficiencies of MERV-rated filters are based on the performance of over 200 actual filters from MERV 4 through 16, but the tool also allows users to enter custom characteristics for specific filters.
- The sheet also calculates the filter droplet nuclei efficiency, based on the cited research but allows a user to adjust the anticipated distribution of virus, as desired. It also allows specification of the zone (room) air distribution effectiveness from ASHRAE Standard 62.1 to account for the impact of the HVAC system air delivery method on the degree of mixing. Default calculations assume perfect mixing. Finally, the tool allows for the target air changes to be adjusted if an owner wants to achieve a different per cent removal in lieu of the recommended 95%.
- Heating season guidance: The guide now includes data to consider for heating of outdoor air and the potential impact on pre-heat coils in systems.
- Adjustments to align with Core Recommendations: The Core Recommendations were released in January 2021, and this guidance document needed to be updated to ensure that the information provided aligned with the intent of those recommendations. This included minimum outdoor air supply and filter efficiency requirements and their role in an equivalent outdoor air supply-based risk mitigation strategy.
According to ASHRAE, the guidance still addresses the tactical commissioning and systems analysis needed to develop a Building Readiness Plan, increased filtration, air cleaning strategies, domestic and plumbing water systems, and overall improvements to a system’s ability to mitigate virus transmission.
Building for the “new normal”
As the world continues to grapple with an ever-shifting economic landscape, owing to the COVID-19 pandemic, stakeholders in the building sector across the GCC region have observed how the pandemic has triggered an evaluation and reassessment of priorities. Ashok Jha, Head FM and Retrofit Projects, Universal Voltas, points out that the unprecedented disruption caused by COVID-19 has prompted many organisations to take actions they have been putting off for some time, including launching new digital services and evolving their business models, enabling greater flexibility in their working and implementing cost optimisation measures.
However, Jha says, perhaps the most notable trend would be the move towards a greater number of retrofit projects in the region. “Because of the COVID-19 pandemic, the oil prices plummeted to one of the lowest levels and government revenues went down in the GCC region,” he says. “This has led to reduced spending across all sectors, including new construction, with the current market seeing greater push towards shallow retrofitting, deep retrofitting, energy conservation and reducing the building carbon footprint in the existing buildings to make them more sustainable.” Jha says that since the number of existing buildings in Oman, Kuwait and the UAE is very high compared to new buildings, there was also a need to address the physical deterioration of the buildings, due to functional and economic obsolescence, and to make them more sustainable. “Because of this, there is a surge in demand for the retrofitting of the existing buildings across the GCC region,” he says (see sidebar).
Andrea Di Gregorio, Executive Director, Reem, Ras Al Khaimah Municipality, also believes the region is poised to see a strong pipeline of retrofit projects. “More focus is being put in refurbishing existing buildings, to bring them up-to-speed with the latest best practices in sustainability,” he says. “We see an increase in interest from building owners in retrofit activities, and we expect this interest to further increase throughout 2021 and in the coming years.”
Energy efficiency and sustainability
Another major driver for retrofits is the move towards energy efficient and sustainable practices, which has long been heralded by experts in the sector. Jha points out that because of the detrimental impact of buildings on the environment, with occupied buildings and the construction sector accounting for 36% of the global energy consumption and nearly 40% of total direct and indirect CO2 emissions according to International Energy Agency (IEA), the UAE has begun to actively transition into smart and sustainable cities, which has turned the focus on the energy efficiency of the buildings, specifically existing ones.
In addition to its impact on overall sustainability efforts, much of the move can be attributed to growing awareness on return of investment in terms of reduced operational cost. As Jha points out, retrofitting primarily refers to the measures being taken to replace legacy energy and utility systems with new and energy-efficient technologies. “These technologies not only reduce energy consumption and decrease carbon emissions but also lower maintenance costs, improve safety, enhance productivity, boost property valuations and also prolong the useful life of the assets and the building as a whole,” he says. “In a nutshell, we can say that OPEX of the building reduces and the asset value increases. Hence, it is becoming important day by day to retrofit buildings to not only make them more sustainable for the future but also to derive economical value by reducing the operational cost and, in turn, optimise the rentals and make them more lucrative for the tenants.”
Weighing in, Di Gregorio says that sustainable buildings often result in lower life cycle cost of the building itself. “If sustainability features are carefully selected, operational savings – in terms of energy and water usage and equipment maintenance – typically exceed any incremental investments that those features require,” he says. “For this reason, in a perfect market, where developers are able to fairly monetise their investments in higher quality buildings, we would expect for tenants any rent premiums for more sustainable buildings to be exceeded by the value of operational savings.”
Jha adds that as energy prices continue to rise, the relative benefits of energy efficiency will become increasingly important, and this is leading to a huge surge in demand for equipment, such as Smart LED lights and motion sensors, air curtains and FAHUs, energy-efficient AHUs, FCUs or split units and VAV systems. This has also led to greater demand for water usage reduction through the use of low-flow fixtures, sensors, waterless urinals and low-flush WCs, and also for photovoltaic panels on rooftops to generate electricity from the solar power, among other solutions.
A renewed focus on IAQ
While the return on investment (ROI) from retrofitting for energy efficiency is becoming clear, stakeholders are hopeful that the new wave of retrofits would also accommodate enhancements of indoor air quality (IAQ), which has been typically overlooked over the past years. Di Gregorio says that he believes this would be the case. “There is increasing interest in IAQ, partly driven by COVID-19 concerns,” he says. “Some awareness and technical barriers are there; nonetheless we foresee development in this area in the future.”
Jha shares a similar opinion. He says: “Fear of pandemic is looming large in the minds of the people, and therefore, while carrying out the retrofitting of their buildings, owners are ensuring that retrofit projects also take into consideration IAQ of the buildings, where people are currently spending more than 90% of their time and also to reduce the chances of contamination through virus, bacteria, moulds and fungi.”
Di Gregorio says there is a lot of focus on safety and security from building owners, particularly in what concerns disinfection of common areas. “This sometimes adds to other measures, like filtration, turning into improved air quality,” he says. Jha adds that some of the measures that building owners are taking include Demand Control Ventilation through C02 sensors, fitting volume control dampers, ultraviolet lamps in AHUs, ultraviolet germicide irradiation and MERV 13/14 filters. He further adds that there has been an increase in the use of humidifiers and dehumidifiers to maintain humidity in the range of 40-60%, where the microbial and fungal growth is minimal.
Jha also says that the majority of the offices are allowing their staff to work from home and that people are spending more than 90% of their time indoors. “This further necessitates that apt measures are taken by the occupants to ensure proper lux levels, ergonomics and IAQ, as these will have a profound impact on their health and wellbeing and, in turn, impact their productivity,” he says. “Hence, there cannot be a better time than now to address the Indoor Environment Quality (IEQ) issues, if any.” Jha says these are the factors driving a lot of investment being done by the property owners in the built-environment to retrofit their buildings to ensure proper IAQ against the traditional retrofit, where emphasis was mainly towards energy efficiency.
Making a case for retrofits
Keeping in mind the tangible and intangible benefits of retrofitting, Di Gregorio believes there is more than enough evidence to drive building owners to invest in such initiatives. “If building owners are not thinking about retrofits, they definitely should!” he says. “Retrofit projects tend to have very favourable returns. We are observing that for comprehensive retrofits of commercial buildings in Ras Al Khaimah, the payback time is 3-5 years. And the contracting standards that are being adopted often provide forms of guarantees for the investor on those returns.”
Jha, agreeing, says that in spite of the change in the occupancy profile of buildings, property owners must continue to retrofit within the built-environment. “Retrofitting of existing buildings offers tremendous opportunities for improving asset performance in terms of utilities,” he says. “Retrofitting also offers a potential upside in the overall performance of the building through improved energy efficiency, increased staff productivity, reduced maintenance costs, and better thermal comfort.” Jha believes that such key drivers should serve as a motivation and incentive for building owners, who are on the fence about investing in retrofit projects.
Retrofitting in Kuwait, Oman and the UAE
COVID-19 has had a significant adverse impact on organisations, people’s health, their livelihoods and the economy at large in the GCC region countries, says Ashok Jha, Head, FM & Retrofit Projects, Universal Voltas LLC. However, Jha is quick to point out that while the duration and severity of COVID-19’s impact on economies and sectors will undoubtedly vary, companies and governments in the GCC region have done well to set in motion a “look ahead, anticipate, innovate and adjust” roadmap, which has led the construction sector to focus on energy optimisation and retrofitting in existing buildings, which is a key to sustainable construction.
Citing figures from Global Data, a leading data and analytics company, Jha says that Oman’s construction industry contracted sharply in 2020, plummeting by nearly around -10.3%. “The industry is struggling with challenges presented by the COVID-19 outbreak, low oil prices, and the impact of sovereign credit rating downgrades,” he says. Further compounding the downside risks to the outlook for the industry, the Omani Government has had to rationalise spending.”
Jha adds that given the limited prospects for the government to boost investment in infrastructure and other investment projects, a recovery in the construction sector is expected to be very slow. “Global Data currently expects the construction industry to fall further in 2021, with output contracting by -5.8%,” he says. “The fiscal plan by the Oman Government is intended to reduce public debt, increase the state’s reserves, and diversify revenue away from the oil sector.”
Owing to these factors, Jha believes that new construction spend will be very minimal, and more impetus will be on the retrofitting, deep retrofitting, fit-outs and energy performance optimisation in the built-environment in Oman.
Kuwait has faced similar challenges, Jha says, adding that the construction market shrunk in the year 2020 at about -9.5% approximately, as per Global Data. “The construction industry is struggling with the challenges presented by the outbreak of COVID-19, low oil prices and the impact of sovereign credit rating downgrades,” he says. “Because of this, focus is more towards existing buildings in Kuwait.”
Jha adds that within the built-environment in Kuwait, residential buildings constitute around 81%, commercial buildings are 11%, whereas government buildings constitute four per cent; the remaining four per cent includes commercial, industrial, agricultural and services. “Also, Kuwait has one of the highest per capita electricity consumption and carbon footprint globally, which further necessitates the retrofitting of the buildings to make them more sustainable,” he says. “All the above factors, along with the economic strain, is forcing Kuwait to focus on energy conservation, deep retrofitting, retrofitting and fit-outs in the built-environment with a very minimal spending on new construction.”
Sharing observations on the UAE market, in particular, Jha says that the COVID-19 outbreak, coupled with low oil prices, has led the construction output in the UAE to contract by nearly 4.8% in 2020, but that a rebound is expected in 2021, as per Global Data. “New project opportunities are expected to be minimal in the coming quarters, as the government is consolidating its widening fiscal debt and COVID-19-related force majeure,” he said. “Over the medium- to longer-term, government investment will remain focused on upgrading physical infrastructure and reforming the financing and regulatory environment.”
Jha adds that the UAE has set high targets for building retrofit, which are reflected in the UAE Energy Strategy 2050 and the Dubai Integrated Energy Strategy. “The latter targets an overall 30% reduction in energy and water use by 2030,” he says. “To support this, Etihad ESCO aims to retrofit 30,000 buildings in the next 10 years and generate 1.68TWh energy savings and around 5.64 BIG of water savings by year 2030.”
ASHRAE releases core recommendations for reducing airborne infectious aerosol exposure
ATLANTA, Georgia, 14 January 2021: The ASHRAE Epidemic Task Force has released new guidance to address control of airborne infectious aerosol exposure and recommendations for communities of faith buildings, ASHRAE said through a Press release.
An infectious aerosol is a suspension in air of fine particles or droplets containing pathogens, such as the SARS-CoV-2 virus, which can cause infections when inhaled, ASHRAE said. They can be produced by breathing, talking, sneezing and other as well as by flushing toilets and by certain medical and dental procedures, it added.
ASHRAE’s Core Recommendations for Reducing Airborne Infectious Aerosol Exposure concisely summarize the main points found in the detailed guidance documents produced by the ASHRAE Epidemic Task Force, it said. They are based on the concept that ventilation, filtration and air cleaners can be combined flexibly to achieve exposure reduction goals, subject to constraints that may include comfort, energy use and costs, it added.
“This guidance outlines a clear approach for lessening the risk of infectious aerosol exposure for building occupants that can be applied in a wide range of applications, from homes to offices, to mobile environments, such as vehicles and ships,” said William Bahnfleth, Chair, ASHRAE Epidemic Task Force. “ASHRAE’s Core Recommendations are based on an equivalent clean air supply approach that allows the effects of filters, air cleaners, and other removal mechanisms to be added together to achieve an exposure reduction target.”
According to ASHRAE, specific recommendations include the following:
- Public health guidance
- Follow all regulatory and statutory requirements and recommendations.
- Ventilation, filtration, air cleaning
- Outdoor airflow rates guidance for ventilation, as specified by applicable codes and standards.
- Recommendations on filters and air cleaners that achieve MERV 13 or better levels of performance.
- The use of air cleaners.
- Control options that provide desired exposure reduction while minimizing associated energy penalties.
- Air distribution.
- Promote the mixing of space air.
- HVAC system operation
- Maintain temperature and humidity design set points.
- Maintain equivalent clean air supply required for design occupancy.
- Operate systems for a time required to achieve three air changes of equivalent clean air supply.
- Limit re-entry of contaminated air.
- System commissioning
- Verify that HVAC systems are functioning as designed.
According to ASHRAE, the task force’s Communities of Faith Buildings guidance offers recommendations on conducting worship services under epidemic conditions.
Rick Karg, ASHRAE Epidemic Task Force member, said: “The intent of the Communities of Faith guidance is to offer those who operate and care for buildings used for worship a plan for implementing short- and long-term HVAC strategies to reduce the possibilities of transmission of the SARS-CoV2-2 virus. The document also helps communities move toward a new ‘normal’ operation after this public health emergency nears an end.”
According to ASHRAE, recommendations for Communities of Faith include the following:
- Identify HVAC system characteristics. Compile and review operation and maintenance manuals and schedules.
- Verify HVAC systems are well maintained and operating as intended. For maintenance, follow the requirements of ASHRAE Standard 180 – 2018, Standard Practice for the Inspection and Maintenance of Commercial HVAC Systems.
- Consider PPE when maintaining HVAC systems, including filters, coils and drain pans.
- Operate HVAC systems, if present, with system fan set to run continuously when building is occupied for services or cleaning.
- Operate the system for a time required to achieve three equivalent air changes of outdoor air (effect of outdoor air, filtration and air cleaners) before the first daily occupancy and between occupied periods, if appropriate. Three equivalent air changes can be calculated using ASHRAE’s Building Readiness Guide.
To view the complete ASHRAE Core Recommendations For Reducing Airborne Infectious Aerosol Exposure and Communities of Faith Building guidance, ASHRAE suggested visiting ashrae.org/COVID-19.