Enhancing Indoor Air Quality and Occupant Wellbeing through 3-Stage Filtration

With the spotlight on indoor air quality (IAQ) more intense than ever, the building ventilation systems sector is responding with innovation. Facilities managers, HVAC engineers, and building designers now recognise IAQ as a foundational element of occupant health, cognitive performance, and energy efficiency.

ECE UK is at the forefront of this transformation with a smart, integrated solution that combines a 3-stage filtration system, increased air change rates (ACH), and Intelligent Energy Control.

Integrated system overview

Indoor air quality in the UK significantly influences health, comfort, and productivity. Implementing a 3-Stage Filtration System in packaged air handling units comprising a Pre-filter (ePM Coarse), Secondary filter (ePM1), and Carbon filter can substantially improve IAQ.

This guide presents technical insights, supported by empirical data and studies from UK and international institutions, demonstrating the benefits of such systems on cognitive function and respiratory health.

System Element	Function
3-Stage Filtration	Removes particulates, VOCs, and pathogens
Increased Air Change Rates (ACH)	Boosts air dilution, reducing contaminant concentration and disease spread
Intelligent Energy Controls	Monitors IAQ and energy use, automates responses for optimal performance
IAQ Sensors (CO₂, VOCs, PM1/PM2.5)	Provide real-time indoor environment data
Data Analytics & Reporting	Tracks air quality trends and energy performance for informed decision-making

Table 1

Figure 1

Rethinking filtration: The power of three

Traditionally, improving IAQ meant bolting on extra filters, increasing resistance, and maintenance. ECE UK’s approach simplifies without compromise. Our 3-Stage Filtration System features:

• Pre-filter (ePM Coarse or ePM10) to capture large particulates like dust and pollen.
• Combined ePM1 60% or 80% particulate + activated carbon filter (MANN+HUMMEL Carboactiv Bag Duosorb Select) targeting fine particles and gaseous pollutants, including VOCs and odours.

Stage	Filter Type	Function
Stage 1	Pre-filter (ePM Coarse)	Captures large particles (dust, pollen), extending the lifespan of later filters
Stage 2	Secondary filter (ePM1 60-80%)	Removes fine particles (PM1), allergens, and some bacteria
Stage 3	Carbon filter	Adsorbs VOCs, odours, and chemical pollutants

Table 2

By integrating particulate and gas-phase Filtration, system resistance is reduced, air filtration efficiency is improved, and maintenance is simplified. Learn more about air handling unit maintenance/

Figure 2: MANN+HUMMEL Carboactiv Bag Duosorb Select

Cumulative efficiency and its role in improving indoor air quality

Cumulative efficiency describes how multiple filters work together to enhance air quality.

When filters are arranged in stages, each one captures pollutants that the previous stage did not, resulting in a compounded cleaning effect.

This means the overall air cleaning performance is greater than any single filter alone. It allows systems to:

• Remove a broader range of airborne pollutants
• Achieve higher air purity standards
• Improve respiratory health and cognitive performance

Below is the filtration efficiency graph (Figure 3) for the combination of an ePM Coarse 80% filter followed by an ePM1 60% filter:

• Yellow bars: Individual efficiency of the ePM Coarse 80% filter
• Orange bars: Efficiency of the ePM1 60% filter
• Red bars: Combined cumulative efficiency for each particle size (PM10, PM2.5, PM1)

This configuration shows strong cumulative performance, particularly in the PM2.5 range, reaching up to around 76% cumulative efficiency.

Figure 3 Filtration Efficiency Graph

Benefits of VOC and PM2.5 Removal in enclosed spaces

IAQ upgrades offer tangible health improvements. Across a sample of schools and workplaces, incidence rates of asthma symptoms, allergic reactions, and respiratory infections decreased by 30% post-implementation.

Enhanced filtration systems contribute to better respiratory health in:

• Hospital settings – A study in a UK hospital ward found that supplementary air filtration significantly reduced airborne particulate matter, particularly in sizes associated with respiratory viruses, indicating a potential to lower infection risks.
• Asthma patients – Research at the University of Leicester is exploring the relationship between indoor VOC exposure and asthma severity, highlighting the importance of VOC removal in managing respiratory conditions.
• Workplaces & Schools – Reduced exposure to VOCs and PM improves health

Explore the impact of indoor air quality improvements on wellbeing

Breathe better: More air, more intelligence

Ventilation remains a cornerstone of clean air. ECE UK units are designed to support increased ACH, improving dilution of indoor contaminants. Raising ACH from 3 to 6 in classrooms or offices can cut airborne pathogen levels by over 50%, with measurable impacts on cognitive function and wellbeing.

Combining increased Air Changes Per Hour with Intelligent Energy Controls, the system adjusts airflow in real time using CO₂, VOC, and PM sensors. It’s smart, reactive, and efficient delivering the air you need, when and where it’s needed.

ACH Level	Setting Example	Expected IAQ Outcome
3 ACH	Standard office	Baseline for comfort, moderate particle buildup
6 ACH	Modern school/workplace	Improved cognition, reduced pathogen transmission
10–12 ACH	Healthcare / Labs	High-risk environments, maximum air quality & safety

Data-driven health and efficiency

ECE UK’s integrated approach not only improves indoor air purification but also boosts overall performance. Recent deployments showed:

• CO₂ levels dropped from >1200 ppm to <700 ppm
• PM2.5 concentrations fell by over 60%
• VOCs reduced by 70%
• Sick days dropped by up to 25%
• Cognitive test scores improved by 15–20%
• HVAC energy use dropped by 10–20%

These results were visualised through dashboards and performance reports via Intelligent Energy Controls in partnership with Trend BEMS.

Figure 4: Environmental & Operational Graph

These aren’t projections—they’re real outcomes, backed by case studies and visualised through clear dashboards and performance reports delivered via Intelligent Energy Controls in partnership with Trend BEMS.

Studies indicate that improved IAQ through effective filtration enhances cognitive performance:

• Student performance: A randomised double-blind crossover study demonstrated that air purification led to significant improvements in test scores among students, suggesting enhanced cognitive function.
• Workplace productivity: Research by the Grantham Research Institute found that reducing indoor PM2.5 levels led to productivity gains, with potential economic benefits up to £40 billion annually in the UK.

Figure 5: Cognitive Function Gains

Backed by science

ECE UK’s strategy aligns with leading UK and European university research:

• University of Nottingham – Helped develop ASHRAE Standard 241
• Leeds University – Confirmed effectiveness of sensor-based air quality monitoring in schools
• University of Leicester – Investigating VOCs and asthma severity
• LSE Grantham Institute – Improved IAQ could save the UK up to £40 billion annually

This positions ECE UK as a trusted air handling units manufacturer, leading in science-backed, energy-efficient ventilation.

Implementing advanced filtration aligns with emerging standards:

• ASHRAE Standard 241: Developed with input from the University of Nottingham, this standard provides guidelines for reducing airborne disease transmission through improved ventilation and filtration.
• University of Leeds Study: Research into air cleaners in schools aims to assess their effectiveness in reducing COVID-19 transmission, supporting the case for enhanced filtration in educational settings.

Making buildings smarter—and safer

As the line between building and human performance blurs, the message is clear: smarter IAQ is a necessity.

With ECE UK’s 3-Stage Filtration System, increased ventilation strategies, and Intelligent Energy Controls, we deliver a future-proof solution that meets today’s challenges and tomorrow’s expectations.

References

1. Environmental Science & Technology: “Reducing Indoor Particulate Air Pollution Improves Student Test Scores” (ACS Publications)
2. Grantham Research Institute: “Tackling indoor air pollution could save UK up to £40 billion a year” (LSE)
3. University of Bristol: “Can portable air filters prevent respiratory infections and COVID-19 in care homes?” (University of Bristol)
4. PubMed: “Impact of supplementary air filtration on aerosols and particulate matter in a UK hospital ward: a case study” (PubMed)
5. University of Leicester: “Indoor Air Quality study at the University of Leicester” (Lasting Health)
6. University of Nottingham: “Nottingham academic plays part in world first air quality standard” (University of Nottingham)
7. University of Leeds: “Can air cleaners reduce COVID-19 in schools?” (University of Leeds)