Interplay of ventilation and filtration: Differential analysis of cost function combining energy use and indoor exposure to PM2.5 and ozone

Abstract This study investigated the effects of ventilation and filtration on building energy consumption and exposure to PM2.5 and ozone in U.S. offices. Energy use and indoor PM2.5 and ozone concentrations were predicted in 15 locations for a typical office with either a constant air volume (CAV) or variable air volume (VAV) mechanical system. For each office and location, annual simulations were performed with combinations of fixed ventilation ranging 20–100 CFM/occ (9.4–47 L/s/occ) and filters ranging in efficiency corresponding to MERV 8–16 and HEPA. Energy use was monetized using historic costs, and PM2.5 and ozone exposures were monetized using incidence valuations and concentration-response functions. These outcomes were combined into a singular cost function, which was characterized empirically as a function of ventilation and filtration. Various partial derivatives of the cost function were calculated to observe trends and interdependencies. Exposure cost was 5.5 times higher than energy cost for cases with common filters (MERV 8–11). Even with high filter efficiency, exposure cost was greater than energy cost on average. Filtration had a much stronger effect than ventilation on indoor contaminant levels and the total cost function. The differential analysis revealed that ventilation and filtration complement each other: Implementing a high efficiency filter can mitigate negative effects of ventilation, and higher ventilation rates can increase the efficacy of filtration (e.g. increasing ventilation from 20 to 60 CFM/occ increased filtration efficacy by 1.2–1.5 for VAV offices).

[1]  R. Burnett,et al.  Effects of particulate and gaseous air pollution on cardiorespiratory hospitalizations. , 1999, Archives of environmental health.

[2]  Wenjuan Wei,et al.  Indoor air quality requirements in green building certifications , 2015 .

[3]  Adams Rackes,et al.  Modeling impacts of dynamic ventilation strategies on indoor air quality of offices in six US cities , 2013 .

[4]  Tom Ben-David,et al.  Alternative ventilation strategies in U.S. offices: Saving energy while enhancing work performance, reducing absenteeism, and considering outdoor pollutant exposure tradeoffs , 2017 .

[5]  Andrew K. Persily,et al.  Analysis of Ventilation Data from the U.S. Environmental Protection Agency Building Assessment Survey and Evaluation (BASE) Study , 2004 .

[6]  U. Haverinen-Shaughnessy,et al.  Association between substandard classroom ventilation rates and students' academic achievement. , 2011, Indoor air.

[7]  Adams Rackes,et al.  Alternative ventilation strategies in U.S. offices: Comprehensive assessment and sensitivity analysis of energy saving potential , 2017 .

[8]  Christine A Erdmann,et al.  Mucous membrane and lower respiratory building related symptoms in relation to indoor carbon dioxide concentrations in the 100-building BASE dataset. , 2004, Indoor air.

[9]  Pawel Wargocki,et al.  The performance and subjective responses of call-center operators with new and used supply air filters at two outdoor air supply rates. , 2004, Indoor air.

[10]  Derek Clements-Croome,et al.  Ventilation rates in schools , 2008 .

[11]  Atila Novoselac,et al.  The relationship between filter pressure drop, indoor air quality, and energy consumption in rooftop HVAC units , 2014 .

[12]  S. Palkonen,et al.  What does the scientific literature tell us about the ventilation–health relationship in public and residential buildings? , 2015 .

[13]  M S Waring,et al.  Real‐time transformation of outdoor aerosol components upon transport indoors measured with aerosol mass spectrometry , 2017, Indoor air.

[14]  Chikao Kanaoka,et al.  Pressure drop of air filter with dust load , 1990 .

[15]  Jeffrey A. Siegel,et al.  Ultrafine particle removal and generation by portable air cleaners , 2008 .

[16]  C J Weschler,et al.  Ozone in indoor environments: concentration and chemistry. , 2000, Indoor air.

[17]  M S Waring,et al.  Particle loading rates for HVAC filters, heat exchangers, and ducts. , 2008, Indoor air.

[18]  Daniel Krewski,et al.  Cardiovascular Mortality and Exposure to Airborne Fine Particulate Matter and Cigarette Smoke: Shape of the Exposure-Response Relationship , 2009, Circulation.

[19]  E. R. Jayaratne,et al.  Indoor aerosols: from personal exposure to risk assessment. , 2013, Indoor air.

[20]  H. K. Fai,et al.  Characterization of VOCs, ozone, and PM10 emissions from office equipment in an environmental chamber , 2001 .

[21]  M. Orme.  Estimates of the energy impact of ventilation and associated financial expenditures , 2001 .

[22]  Bing Liu,et al.  U.S. Department of Energy Commercial Reference Building Models of the National Building Stock , 2011 .

[23]  John Staudenmayer,et al.  A study of indoor carbon dioxide levels and sick leave among office workers , 2002, Environmental health : a global access science source.

[24]  B. Stephens,et al.  Using portable particle sizing instrumentation to rapidly measure the penetration of fine and ultrafine particles in unoccupied residences , 2017, Indoor air.

[25]  Yixing Chen,et al.  EnergyPlus and CHAMPS-Multizone co-simulation for energy and indoor air quality analysis , 2015 .

[26]  M. Waring,et al.  Volatile organic compound conversion by ozone, hydroxyl radicals, and nitrate radicals in residential indoor air: Magnitudes and impacts of oxidant sources. , 2015, Atmospheric environment.

[27]  Tom Ben-David,et al.  Impact of natural versus mechanical ventilation on simulated indoor air quality and energy consumption in offices in fourteen U.S. cities , 2016 .

[28]  O Seppänen,et al.  Reduction potential of urban PM2.5 mortality risk using modern ventilation systems in buildings. , 2005, Indoor air.

[29]  W. H. Engelmann,et al.  The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants , 2001, Journal of Exposure Analysis and Environmental Epidemiology.

[30]  Steven N. Rogak,et al.  Financial implications of modifications to building filtration systems , 2015 .

[31]  Marjorie Musy,et al.  Application of sensitivity analysis in building energy simulations: combining first and second order elementary effects Methods , 2012, ArXiv.

[32]  J. Schwartz,et al.  Reduction in fine particulate air pollution and mortality: Extended follow-up of the Harvard Six Cities study. , 2006, American journal of respiratory and critical care medicine.

[33]  R. Burnett,et al.  Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. , 2002, JAMA.

[34]  Lidia Morawska,et al.  Influence of ventilation and filtration on indoor particle concentrations in urban office buildings , 2013 .

[35]  Arthur M Winer,et al.  Relationships of Indoor, Outdoor, and Personal Air (RIOPA). Part I. Collection methods and descriptive analyses. , 2005, Research report.

[36]  Parham Azimi,et al.  HVAC filtration for controlling infectious airborne disease transmission in indoor environments: Predicting risk reductions and operational costs , 2013, Building and Environment.

[37]  Gabriel Bekö,et al.  Is the use of particle air filtration justified? Costs and benefits of filtration with regard to health effects, building cleaning and occupant productivity , 2008 .

[38]  Parham Azimi,et al.  Estimates of HVAC filtration efficiency for fine and ultrafine particles of outdoor origin , 2014 .

[39]  S. Dutton,et al.  Health and economic implications of natural ventilation in California offices , 2013 .

[40]  João Dias Carrilho,et al.  Towards sustainable, energy-efficient and healthy ventilation strategies in buildings: A review , 2016 .

[41]  José Manuel Cejudo López,et al.  Uncertainties and sensitivity analysis in building energy simulation using macroparameters , 2013 .

[42]  Brent Stephens,et al.  Modeling the energy and cost impacts of excess static pressure in central forced-air heating and air-conditioning systems in single-family residences in the U.S. , 2015 .

[43]  S. Johnston,et al.  Detection of airborne rhinovirus and its relation to outdoor air supply in office environments. , 2004, American journal of respiratory and critical care medicine.

[44]  Standard Ashrae.  Thermal Environmental Conditions for Human Occupancy , 1992 .

[45]  C J Weschler,et al.  The influence of ventilation on reactions among indoor pollutants: modeling and experimental observations. , 2000, Indoor air.

[46]  J. Samet,et al.  Ventilation rates and health: multidisciplinary review of the scientific literature. , 2011, Indoor air.

[47]  Jennifer M. Logue,et al.  A Method to Estimate the Chronic Health Impact of Air Pollutants in U.S. Residences , 2011, Environmental health perspectives.

[48]  C J Weschler,et al.  Indoor ozone exposures. , 1989, JAPCA.

[49]  P. L. Jenkins,et al.  Activity patterns of Californians: Use of and proximity to indoor pollutant sources , 1992 .

[50]  Wei Jiang,et al.  Analysis of Building Envelope Construction in 2003 CBECS , 2007 .

[51]  M. Hlatky,et al.  Cost-Effectiveness of Coronary Artery Bypass Grafts Versus Percutaneous Coronary Intervention for Revascularization of High-Risk Patients , 2006, Circulation.

[52]  Nabil Nassif,et al.  The impact of air filter pressure drop on the performance of typical air-conditioning systems , 2012 .

[53]  M Hamilton,et al.  Perceptions in the U.S. building industry of the benefits and costs of improving indoor air quality. , 2016, Indoor air.

[54]  M. J. Hutzler,et al.  Emissions of greenhouse gases in the United States , 1995 .

[55]  J. E. Janssen,et al.  Ventilation for acceptable indoor air quality , 1989 .

[56]  Mary G. George,et al.  Costs of hospitalization for stroke patients aged 18-64 years in the United States. , 2014, Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association.

[57]  Thomas E McKone,et al.  Indoor particulate matter of outdoor origin: importance of size-dependent removal mechanisms. , 2002, Environmental science & technology.

[58]  Charles J. Weschler,et al.  Ozone’s Impact on Public Health: Contributions from Indoor Exposures to Ozone and Products of Ozone-Initiated Chemistry , 2006, Environmental health perspectives.

[59]  W J Fisk,et al.  Associations between indoor CO2 concentrations and sick building syndrome symptoms in U.S. office buildings: an analysis of the 1994-1996 BASE study data. , 2000, Indoor air.

[60]  William J. Fisk,et al.  Quantification of the association of ventilation rates with sick building syndrome symptoms , 2009 .

[61]  Nuno M. Mateus,et al.  Validation of EnergyPlus thermal simulation of a double skin naturally and mechanically ventilated test cell , 2014 .

[62]  Zheng O'Neill,et al.  Uncertainty and sensitivity decomposition of building energy models , 2012 .

[63]  N. Kochhar,et al.  Ventilation Rates in Schools and Learning Performance , 2007 .

[64]  D K Milton,et al.  Risk of sick leave associated with outdoor air supply rate, humidification, and occupant complaints. , 2000, Indoor air.

[65]  Mark A. Halverson,et al.  Review of Pre- and Post-1980 Buildings in CBECS - HVAC Equipment , 2006 .

[66]  Jooyong Kim,et al.  Prediction of air filter efficiency and pressure drop in air filtration media using a stochastic simulation , 2008 .

[67]  Andrew K. Persily,et al.  Indoor air quality analyses of commercial reference buildings , 2012 .

[68]  Gabriel Bekö,et al.  Further studies of oxidation processes on filter surfaces: Evidence for oxidation products and the influence of time in service , 2007 .

[69]  W. Nazaroff.  Indoor particle dynamics. , 2004, Indoor air.

[70]  L. Ricciardi,et al.  Air flows and pressure drop modelling for different pleated industrial filters , 2002 .

[71]  Alex K. Jones,et al.  Indoor environmental quality in a dynamic life cycle assessment framework for whole buildings: Focus on human health chemical impacts , 2013 .

[72]  W. Fisk,et al.  Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance , 2012, Environmental health perspectives.

[73]  Jian Zhang,et al.  Enhancements to ASHRAE Standard 90.1 Prototype Building Models , 2014 .

[74]  A Rackes,et al.  Do time-averaged, whole-building, effective volatile organic compound (VOC) emissions depend on the air exchange rate? A statistical analysis of trends for 46 VOCs in U.S. offices. , 2016, Indoor air.

[75]  O Seppänen,et al.  Ventilation and performance in office work. , 2006, Indoor air.

[76]  Brent Stephens,et al.  Measuring the penetration of ambient ozone into residential buildings. , 2012, Environmental science & technology.