Growing focus on IAQ challenges for specifiers and HVAC manufacturers

1 Introduction
2 IAQ: approaches and solutions
3 Regulation and geographies
4 Industry impact and future scenarios
5 Conclusions
6 Related articles on Designing Buildings

[edit] Introduction

The concept of indoor air quality (IAQ) has gained the increased attention of HVAC specifiers in the commercial space. Designers, especially in Europe and the US, have striven to specify fully featured ventilation solutions to keep pace with the evolution of regulatory compliance and the increasing sophistication of end user requirements.

To enhance the comfort and health and safety of built environment occupants, ventilation systems have become elaborate and progressively more customised. In fact, there is no one-size-fits-all solution for IAQ, which remains a vague concept until it is applied to the relevant building site and vertical market.

The health crisis triggered in 2020 by the COVID-19 pandemic has brought the debate on IAQ from closed HVAC industry circles to the broader attention of the mainstream media. The claim that an ill-designed ventilation system in a public space could facilitate the viral contagion among occupants has caused anxiety for the general public and sparked a renewed interest in IAQ facility upgrades within the industry, which has engaged the same building owners. The urgency of enhancing IAQ solutions prompted by the health risk associated with the spread of COVID-19 represents a challenge for regulators and specifiers, a cost for building owners and an opportunity of product development for HVAC manufacturers.

This article analyses developments in the debate on IAQ and formulates some hypotheses on the evolution of the HVAC industry in consideration of this re-centred attention on indoor environmental comfort and safety.

[edit] IAQ: approaches and solutions

[edit] A definition of IAQ

Buildings can host a large quantity of air contaminants, including volatile organic compounds (VOC), particles, toxic substances (such as asbestos and formaldehyde) and microbes such as bacteria and viruses. Prolonged exposure to these contaminants can present both a short-term and long-term health hazard for the occupants who spend a large amount of their time indoors.

One of the key measures adopted to minimise hazards and maximise indoor comfort is to control the emissions of potentially toxic particles at the source by using sustainable furnishing materials, low VOC fittings and natural cleaning products. However, some contaminants (such as atmospheric pollutants and air toxins) are impossible to control at the source and must be managed with the support of mechanical ventilation. In wellness best practice, a holistic approach to IAQ, which combines the use of sustainable materials in construction with effective ventilation systems, is required in building specification.

Table 1. Main pollutants, effect on human health and measures to control

[edit] Ventilation and IAQ

Some of the measures available to minimise the hazard of pollutants in indoor spaces are related to the use of adequate ventilation solutions. There is no off-the-shelf IAQ product available on the market that can meet all the requirements. Rather, depending on site configuration and its operational needs, ad-hoc solutions can be specified, combining HVAC products with dedicated ventilation features. This flexible approach allows specifiers to ensure that regulatory compliance is met not only in relation to IAQ but also with efficiency. The main solutions are reported in the table below.

Table 2. Typical ventilation related IAQ measures for residential and commercial buildings

IAQ ventilation solutions are specified according to applicable building codes and the operational needs of the HVAC system destination of use. The strictest requirements, enforced by regulation, are in place in healthcare facilities in most countries of the world.

Government buildings, education premises and commercial offices also follow more rigorous parameters than other applications regarding IAQ because of their occupancy levels. Decision makers for other verticals, such as hospitality, retail and leisure have typically been more lenient and, with the exception of flagship projects, developers have rarely raised the threshold of their IAQ requirements above bare regulatory compliance.

The reluctance of some developers and financial investors in commercial real estates to invest in IAQ improvement has economic reasons. IAQ enhancement comes with a higher price tag than conventional specification in terms of cost of equipment, installation and maintenance.

Operation-related expenses can also be higher. IAQ is energy intensive. For example, 100% dedicated outdoor air systems (DOAS) are an extra budget burden for the building owner, and they are expensive to run; efficient filters require higher air pressure and therefore more powerful fans; UV purification adds consumption to the electricity load.

The trade-off between IAQ and efficiency is also a conundrum for designers and specifiers. Compliance with efficiency regulation may require compromises on IAQ and vice versa.

[edit] COVID-19: a game changer?

Between February and March 2020, during the outbreak of the COVID-19 epidemic in Guangzhou, China, a cluster of restaurant customers were contaminated by an infected individual who was dining while sitting some distance from them. A study on the case, published by the journal Emerging Infectious Diseases (EID), suggested that the air-conditioned (AC) ventilation system in the restaurant as well as table distancing may have been responsible for carrying the infectious droplets or aerosol particles and eventually causing the contagion. The results of this study were reported, sometimes out of context, in the mainstream media which inferred without full evidence a causality between poorly treated AC system air and COVID-19 transmission.

Understanding the interaction between AC and viral contagion goes beyond the scope of this paper. Scientific studies are being undertaken and conclusive results are yet to be uncovered.

Yet, the EID paper opened a wide debate on the IAQ measures to prevent viral and bacterial infections in indoor spaces. The debate has engaged regulators, specifiers, business owners, the general public and HVAC manufacturers. The latter are striving to develop new solutions to meet the emerging need for more health and safety targeted approaches to IAQ.

Among the solutions proposed to minimise risk of viral contagion are the increase of outdoor air ventilation, higher efficiency filtration and purification. While outdoor air ventilation, and to a lesser extent purification, may require significant and costly alterations to the HVAC system in place, filtration can be improved relatively easily with self-contained units, although additional electricity consumption will be required.

There are signs that regulation is supporting health and safety minded changes to the existing building practices. The federal air quality committee in the US recommended that commercial premises upgrade their HVAC filters to MERV-13 or higher. However, this is not always feasible and/or effective. Thicker filters require more powerful fans with higher energy consumption and in some cases the need for alterations of the HVAC system.

Table 3. Filtration and COVID-19

[edit] Regulation and geographies

The public debate on IAQ is likely to translate into regulatory pressure to enhance the current parameters for air quality in HVAC specification. Before the recommendations of regulators can convert into actionable and enforceable building codes there will be a time lag. Meanwhile, the market demand from building owners and investors, primarily in some key verticals, is likely to steer specification towards best practice schemes - especially in new construction.

BREEAM (Building Research Establishment Environmental Assessment Method) and LEED (Leadership in Energy and Environmental Design) have long been the most adopted schemes for the certification of buildings globally. Both predominantly look at the environmental sustainability of buildings. In contrast, the WELL Building Standard, a relatively new certification scheme (launched in 2015), mainly considers building occupants' health and wellbeing.

LEED includes prescriptions in relation to IAQ in its latest version 4.1 issued in 2018. However, in 2020, the Green Building Council started to release pilot credits to promote precautionary best practice to manage air quality during the COVID-19 pandemic (Safety first).

Regulations, building codes and best practice schemes can impact where there are the resources, building practices and enforcement capabilities. Developed countries have a governance structure, expertise, financial capability and public awareness that can sustain the implementation effort of improvements in construction. In emerging or low-income countries, governments have short-term economic development targets as a political priority, and both the public and private sectors have limited resources for adopting expensive schemes, albeit beneficial in the long term. Paradoxically, in poorer countries the current pandemic, emptying the already depleted public coffers and depressing demand for construction, has worsened the possibility of a progress towards wellness and sustainability.

Figure 1. Pre-COVID-19 regulation in the world’s most important economic blocks. (Please note that both in the EU and US a review of the current standards are under consideration.)

[edit] Industry impact and future scenarios

Despite persisting uncertainty of the duration of the COVID-19 related health crisis, debate within the HVAC industry on the improvements in IAQ levels is not likely to be discarded when the pandemic subsides. Awareness of the health consequences of pollutant exposure, either organic or chemical, has increased and will have an impact on demand for commercial space. IAQ will not only be a tool to manage health emergencies but also an economic factor to consider in designing, planning and specifying commercial HVAC. BSRIA has made some hypotheses on future scenarios for IAQ.

Figure 2. Impact of IAQ on the built environment

Table 4. Hypotheses on evolution of IAQ specification

[edit] Conclusions

The 2020 global COVID-19 pandemic has catalysed attention and built awareness of the importance of hazard-free indoor air in commercial space. Soon, regulatory requirements and building end-user requests will make IAQ an essential aspect of specification. Developers may consider nurturing an interest in enhancing their buildings' environmental wellness as this would help to increase the value of their assets.

The consequences of this transformation on the HVAC industry are as yet hazy. Ventilation and air conditioning companies are developing new solutions and working in partnership with control suppliers, specifiers and regulators specially to resolve the apparent incongruity between efficiency and IAQ.

The process is in its infancy and is confined to the geographical context of the developed countries. Nevertheless, it is clear the trend will continue even when the COVID-19 emergency is finally tamed. This trend will refocus the attention of specifiers of commercial buildings, widening their concept of sustainability in construction from a restricted reference to efficiency confined to cost and carbon emission containment, to a wider target which includes health, wellness and workers' productivity.