Next-generation ventilation should explicitly aim to aggregate, compare, weight, and ultimately integrate ventilation’s numerous impacts, which include the dilution of multiple indoor pollutants, introduction of multiple outdoor pollutants, direct correlations to productivity and absenteeism, and strong influences on energy consumption, peak power demand, and their associated environmental impacts. We propose a multi-criteria decision-making framework based on (i) a comprehensive, scientific accounting of the costs and benefits of ventilation, and (ii) a utility maximization formulation to allow both expression of user preferences and adjustment for uncertainty. The utility function (UF) provides the core criterion and interface to enable more intelligent and holistic ventilation, allowing leveraging of new and future capabilities, including optimized and predictive methods that make use of models or learning, dynamic control that capitalizes on transient effects, and real-time information from new sensors or interconnected information networks and energy grids. We first formulate the UF to be as expansive as possible in scope of impacts, and then conduct a series of sensitivity analyses (SA) to help refine it and identify building parameters that impact it. For the SA data, we made use of an existing simulation-based analysis of eight off-the-shelf ventilation and related strategies that combined economizing, demand-controlled ventilation, and supply air temperature reset. Outcomes were reprocessed to a daily-average basis, and included: electricity consumption, natural gas consumption, median ventilation rates, relative symptom prevalence, relative work performance, and concentrations of carbon dioxide, total volatile organic compounds, and fine particulate matter and ozone of outdoor origin. We first ask, which outcomes are ultimately worth including in the UF? We employ: a principal component analysis of outcomes to check if any are redundant; SA of the impact of each individual outcome on total utility over a range of reasonable user preferences; and an analysis of which outcomes can themselves be meaningfully affected by ventilation. We next turn to an initial evaluation of which building parameters will need to be taken into account by a dynamic strategy that is attempting to maximize utility. We conduct a separate SA where the dependent variable is the daily average ventilation rate observed under each off-the-shelf dynamic strategy, and the independent variables are ~20 varied building parameters as well as 10 explanatory covariates. This task is a crucial first step in simplifying the challenge of generalizing optimal ventilation beyond the case-study level, in the face of tremendous variability among real building and setting characteristics.

Residential whole-house mechanical ventilation has become more important as the impetus has been made to construct homes with less air leakage. Requirements for homes to meet minimum air tightness requirements and to be equipped with mechanical ventilation have even been made mandatory under certain building programs and codes. Homes mechanically ventilated during warm and humid weather will have elevated indoor relative humidity (RH) during low cooling load periods. This requires supplemental dehumidification for at least some low load periods to maintain acceptable RH control. Herein lies a challenge to balance acceptable RH with minimal energy use. A research project was completed to evaluate three specific types of space cooling equipment test configurations in a controlled research lab home. The lab home was furnished and had three bedrooms and two bathrooms located in central Florida. It had automated internal sensible and latent loads, and was ventilated in accordance with ASHRAE 62.2-2013. The main goal of the project was to contribute to the limited body of research seeking to balance space conditioning energy efficiency with good RH control in continuously mechanically ventilated homes, particularly in the hot and humid climate zones of the United States. The focus of the testing was to evaluate space cooling and dehumidifier energy use as well as the resulting indoor RH throughout the home. The three primary test configurations covered in this paper involved: 1) a central ducted fixed-capacity SEER 13 rated system 2) a central ducted variable-capacity SEER 22 rated system, and 3) a SEER 21.5 ductless variable-capacity minisplit. The minisplit was operated as the primary cooling system with central system used for cooling backup during near peak cooling load periods. The project found that the SEER 22 central system configuration used 20% less energy than the SEER 13 central system, and the mini-split configuration used 25% less energy than the SEER 13 system under typical seasonal conditions. Limited supplemental dehumidification was needed to maintain indoor RH below 60% during some low cooling load periods. When needed, dehumidifier use was typically only 1-3 cycles per day (0.18 – 0.58 kWh/day). This paper shares greater details on the variability of indoor RH among the test configurations, factors that resulted in the very limited need for supplemental dehumidification, and recommendations to improve latent performance of variable capacity cooling systems.

Ultraviolet Germicidal Irradiation (UVGI) of cooling coils is done to control biofouling that can increase their flow resistance and decrease heat transfer coefficient. UVGI is also applied in air-handling units to improve indoor air quality (IAQ) by deactivating airborne microorganisms. A typical coil cleaning application delivers a smaller UV dose than an air treatment system, but should provide some collateral air treatment benefit. To date, this effect has not been studied. In this investigation, the benefit of air treatment provided by a cooling coil irradiation system is estimated via simulations employing a subset of the DOE Commercial Reference Buildings library. Benefits are quantified in terms of appropriate measures for each building type: reduced work-loss days (WLD) for office buildings, reduced disability adjusted life years (DALY) for schools, and reduced hospital acquired infections (HAI) for healthcare facilities. UVGI sized for coil cleaning results in a 2% to 12% average reduction in the measure of interest for each building. This reduction is negatively correlated with the average outdoor air fraction in each building type. Combining WLDs with US Gross National Income to monetize savings for Small, Medium, and Large Office Buildings yields between $2.10/m² and $6.61/m², $0.36/m² and $3.04/m², and $0.04/m² and $0.55/m² respectively. Combining DALYs with US Gross National Income to monetize savings for Primary and Secondary Schools results a wide range: $0.01/m² to $1.93/m² due to the large range of values one might reasonably assign to a DALY. In hospitals, Reduction in airborne HAIs resulted in estimated savings of $0.13/m² to $0.62/m².

In order to achieve nearly net zero energy use, both new and energy refurbished existing buildings will in the future need to be still more efficient and optimized. As such buildings can be expected to be already well insulated, airtight, and have heat recovery systems installed, one of the next focal points to limiting energy consumption for thermally conditioning the indoor environment will be to possibly reducing the ventilation rate, or making it in a new way demand controlled. However, this must be done such that it does not have adverse effects on indoor air quality (IAQ). Annex 68, Indoor Air Quality Design and Control in Low Energy Residential Buildings, is a project under IEA’s Energy Conservation in Buildings and Communities Program (EBC), which will endeavor to investigate how future residential buildings are able to have very high energy performance whilst providing comfortable and healthy indoor environments. New paradigms for demand control of ventilation will be investigated, which consider the pollution loads and occupancy in buildings. As well the thermal and moisture conditions of such advanced building shall be considered because of interactions between the hygrothermal parameters, the chemical conditions, ventilation and the wellbeing of occupants. The project is divided into the five subtasks: 1. Defining the metrics, 2. Pollutant loads in residential buildings, 3. Modelling - review, gap, analysis and categorization, 4. Strategies for design and control of buildings, 5. Field measurements and case studies. A flagship outcome of the project is anticipated to be a guidebook on design and operation of ventilation in residential buildings to achieve high IAQ with smallest possible energy consumption The paper illustrates the working program of each of these activities, and the presentation of the Annex project at the conference shall foster some interest and discussion about its work items.

The quality of the environment inside in buildings matters as much as the quality of the environment outdoors. Actually even more, as the health and comfort of the building occupants depend on it. Indoor air quality (IAQ) and thermal comfort conditions (ITQ) as well as hygrometric aspect are concerned to define indoor climate quality (ICQ) which is just part of Indoor Environmental Quality (IEQ). An enlarged concept of IEQ comprises four more quality aspects; sound (ISQ), lighting (ILQ), odor (IOQ), and vibration (IVQ). A high indoor environmental quality can increase health, wellbeing and productivity of building occupants, but also decrease costs for energy and building maintenance. This paper presents materials and methods used on indoor environmental research. In the studies of our research group measured parameters incorporate outdoor climate conditions, indoor thermal, hygrometric, and air quality aspects as well as energy consumption readings including electricity, district heating, and water. Data analysis were performed using computational, visualization and grouping artificial neural network methods. Furthermore, additional external study cases utilizing artificial neural networks (ANN), model-based control, and big data analysis are presented and compared. In this paper, in all 16 examples of intelligent data analysis and knowledge deployment are reviewed in the sense of the benefits of methods used.

High levels of carbon dioxide (CO₂) in classrooms can affect students’ ability to concentrate on academic tasks. CO₂ concentration in an indoor environment is commonly used as a metric for measuring air quality. Although this metric does not reflect all air containments, a high level of CO₂concentration can indicate towards insufficient ventilation of indoor space. In order to mitigate the impacts of climate change, governments in major economies have updated and/or developed building regulations to improve the thermal performance of building fabric, with a view to reduce heating and cooling energy consumption in buildings. With the sustained reduction in heating/cooling energy demand, the share of energy used for artificial lighting increases. For example, artificial lighting accounts for 25-40% of the total building energy consumption in the USA. In addition to the physical factors such as building form, orientation, glazing characteristics and location, energy use for artificial lighting depends on behavioural and psycho-physiological factors of occupants. Previous research suggests that sub-optimal operation of movable insulation such as blinds and curtains have an impact on artificial lighting use and occupant comfort (thermal and visual) with a resulting impact on energy use. This research is aimed at developing a method for optimising the operation of window opening to facilitate natural ventilation and window blinds to reduce energy consumption in a low energy educational building (rated BREEAM excellent ≈ LEED platinum). The research employs model-based optimization using daylight-coupled thermal model in EnergyPlus to model the interrelationships between blind positions; window opening; lighting and heating/cooling energy consumption; and thermal comfort.

In 2006, the voters from the state of California approved the Proposition 1D, which provided $100 million in an incentive grant. Knowing as High Performance Incentive (HPI), this supplemental grant is intended to promote the using of high performance attributes in new and modernization project for K-12 schools. This paper examines the differences on the average amount of change of student achievement results between before and after the completion of high performance attributes for selected funding grantee schools. From the grant description, high performance attributes are designing and using materials that improve indoor environmental quality (IEQ) of schools. Examples include promoting energy and water efficiency, maximizing the use of natural lighting, improving indoor air quality, utilizing materials that emit a minimal amount of toxic substances, and employing acoustics that are conducive to teaching and learning. Criteria from each aspect form the predictors, which used to compare the achievement results built based on the California Standardized Testing and Results Program (STAR) and schools’ Academic Performance Index (API). The general linear mixed linear model (GLMLM) is utilized to analyze the predictors and achievement results. Academic achievement results include several years of results before the project start and the year after the project completion. Average difference of the before and after achievement results is then evaluated based on varied levels of certain predictors.

Pressurization (Blower door) test is a well-established method, performed in order to quantify the total leakage in a building envelope. However, the Blower door results are not really adequate to use when air leakage through the building envelope during natural conditions (non-pressurized) is to be estimated. A common assumption made when estimating air leakage during natural conditions, is to assume that air leakage paths are evenly distributed in the areas of the building envelope. This assumption gives quite poor numerical model results since different leakage configurations are often situated unevenly in the envelope. In order to improve the correspondence between Blower door and air leakage model results, more information on the types and locations of the leakage paths are required as input to simulation models. This paper investigates if additional information from visual inspection and IR-thermography observations at site can increase the precision when estimating air change rates due to air leakage in natural conditions. A numerical model is developed in this study by allocating leakage in various parts of the building envelope. Leakage allocation is assessed by visual inspection and IR-thermography observations at site during the Blower door test. This procedure is tested in the case study of a large single zone church. Blower door and leakage allocation results are used in the numerical model. Model results are compared with tracer gas measurements.

As airtightness is recognized as an essential issue for low energy dwellings, it is nowadays generally included in EP (energy performance) calculations, often through single zone models with uniform air leakage. Because more consideration is often given to energy performance than to indoor air quality issues, air leakage through internal partitions is often disregarded. In order to confirm or infirm such simplification, additional studies are needed. Therefore in the present study air leakage through building envelope and through internal partitions is investigated. Firstly, the paper describes the experimental study, conducted in order to measure multizone air leakages, using the guarded zone pressurization technique. Air leakages of 695 external and internal walls were measured on 28 detached houses with different levels of envelope airtightness. Envelope airtightness varies between n₅₀=0.5 and 8.8 h^-1, with a majority of values under n₅₀= 2.1 h^-1. Secondly, the paper presents the database, which includes for each internal or external wall: building general information, special requirements, building main characteristics (main material, constructional type, ventilation system, insulation type, number of levels, envelope airtightness), measurement protocol, type of wall, measurement input data (altitude, wind velocity, temperatures, area, volume), measurement results (C_L, n, q₅₀, as well as uncertainties). The paper presents in a third part a first analysis of this new database, in order to find most important relationships. For instance, internal and external envelope airtightness levels are not connected: we can obtain high internal leakage with an airtight envelope and respectively, building construction techniques have more influence. As a perspective, the paper concludes with on-going developments concerning another numerical multizone study using these new data. Through these studies, we underline the impact on building airflows of a fine modelling of internal and external airleakages, with consequences on IAQ-bedrooms where people stay the most part of their time.

Since 2008, every measurement of building envelope airtightness performed in France in order to justify an airtightness value for EP-calculation has to be performed by a qualified operator. With the introduction of the French BBC-Effinergie label in 2007 which imposed a limit value for residential buildings airtightness, and then with the application of the current French EP-regulation (RT2012) which imposes those limits to all new residential buildings, the number of qualified operators has been increasing until almost 1,000 in 2015. Each year, those qualified operators fill a database which gathers now information about 90,000 airtightness measurements on residential and non-residential buildings. The Cerema is in charge of this database and performed each year some analyses of those data. It includes 39 fields about building general information (owner, location, use, year of the construction, year of the rehabilitation), special requirements (label, certification), building main characteristics (main material, constructional type, insulation, ventilation system, heating system), measurement protocol (operator, date of measurement, measurement device, time of measurement, method), measurement input data (envelope area, floor area, volume), measurement results (CL, n, qa4, n50, uncertainties) and classification of the leaks (46 categories). In a first part, this paper presents a study of the impact of the leaks distribution on the measurement result, depending on the main material of the buildings, the ventilation system and the insulation. In a second part, this papers proposes an evaluation of the impact of the season of measurement on the measured airtightness for several French regions with different climates, for wood constructions, concrete construction and brick construction. The last part of this paper presents a first analysis of the correlation between the n value and the uncertainties of the measurement result for single-family houses built according to the RT2012.

Infiltration is the ingress of ambient air under normal operating conditions through adventitious openings located in the façade of a building. The importance of reducing infiltration to save energy is highlighted by standards and building codes in many countries. The mean heating season, or other typical, infiltration rate is often inferred from a measurement of an air leakage rate at a pressure differential of 50 Pascals from a whole building pressurization test, often made using a blower door. A simple linear relationship between the air leakage rate and the infiltration rate (infiltration equals air leakage divided by 20) is sometimes assumed to exist and is known by many terms, such as the rule-of-20, leakage-infiltration ratio, Sherman’s ratio, or the Persily-Kronvall rule. The value of 20 is not always fixed, and can be adjusted according to a number of factors, such as building height, shielding, air leakage path size, and climate. The origins of this relationship have previously been unclear, which is problematic if a ratio is to be used with any confidence. This paper investigates the origins of leakage-infiltration ratios (LIRs) and shows that they emerged in the early 1980s from various studies (some unpublished) that measured airtightness and air change rates in a range of single-family dwellings and established empirical relationships between them. It is shown that there is no technical basis for LIRs, yet they are applied by building codes around the world and used to make policy decisions. There widespread use is likely a function of their simplicity, yet they have significant limitations. Accordingly, limitations their use are recommended and more complex alternative models are presented that can be used when more rigorous predictions of infiltration rates are required.

The health effects of outdoor exposure to particulate matter (PM) are well-established and are used to set health-based National Ambient Air Quality Standards (NAAQS). Although much less studied to date, indoor exposure to PM is gaining attention as a potential source of adverse health effects. PM found indoors can be particles of outdoor origin that migrate indoors, or from indoor sources. Indoor PM sources include combustion—cooking, appliances, and like—and occupant activities, notably secondhand smoke. Indoor PM levels have the potential to exceed outdoor levels and NAAQS. In response to a request from the US Environmental Protection Agency, the Institute of Medicine of the National Academies of Sciences, Engineering, and Medicine is conducting a workshop that will address the potential health risks of indoor exposure to particulate matter and the state of scientific understanding regarding them, focusing on PM2.5 and smaller exposures. The workshop will feature invited presentations and discussions regarding the health conditions that are most affected by PM, the attributes of the exposures that are of greatest concern, exposure modifiers, vulnerable populations, exposure assessment, risk management, and gaps in the science. It will take place in February 2016. An Academies report summarizing the workshop will be released in Summer 2016. This presentation summarizes the results of the workshop, reviewing the issues regarding indoor PM exposure and health, and discussing the major unknowns and research needs identified.

Organizations set minimum ventilation standards in order to maintain acceptable indoor air quality (IAQ) in indoor environments. For example, the American Society of Heating, Refrigeration, and Air Conditioning Engineering (ASHRAE) calls for a minimum ventilation rate (VR) of 8.5 l/s-occ at standard occupant density (5 occupants per 100m²) in offices. However, new studies have shown that higher VRs in offices can have positive effects on occupants’ wellbeing, including increased productivity and fewer incidences of absenteeism and sick building syndrome. These positive effects come at a cost associated with increased energy consumption due to additional outdoor air that needs to be conditioned, as well as greater introduction of outdoor-originating to the indoors, namely particulate matter (PM), which can degrade the health of the occupants. This study used a detailed outcome simulation of a typical office environment using EnergyPlus in conjunction with outdoor pollutant data collected by the U.S. Environmental Protection Agency (USEPA) to model the energy consumption and exposure to pollutants with outdoors sources (CO, O₃, NO₂, and PM_2.5) in the indoor environment under various constant VRs (0, 8,5, 17, and 25.5 l/s-occ). The simulation also considered seven filters of different minimum efficiency reporting values (MERVs) to assess their effects on occupant exposure to indoor PM concentrations. The intake-incidence-DALY (IND) method was used to estimate the disability-adjusted life years (DALYs) lost due to the occupants’ exposure to these outdoor originating pollutants. The energy consumption and DALYs lost due to exposure were monetized and their trends were assessed to create a unique empirical function that can predict the likely total cost associated with increased ventilation. This function can be used to estimate a building’s performance under any combination of constant ventilation and filtration within our studied range, so the cost associated with ventilating at high VRs may be easily compared with its many benefits on occupant wellbeing.

We describe and demonstrate a graphical approach that can be used to illustrate the performance of buildings with respect to indoor air quality (IAQ). In the absence of an adequate or agreed-upon IAQ metric(s), we describe a graphical approach to presenting IAQ performance. This approach displays measured or predicted levels of indoor pollutants relative to health-based guidelines or other appropriate reference values. The development of this graphical approach leads to several challenging questions regarding how to characterize building IAQ performance, including the determination of relevant contaminant concentration limits and the impacts of contaminant mixtures. This paper discusses those questions with the intent of promoting future dialog on how to characterize IAQ performance using this graphical or any other approach. Lastly, we briefly describe how the approach can be extended to illustrate the performance of buildings with respect to IAQ and other building parameters (e.g., energy and water consumption).

The prevalence and morbidity of allergic disease and asthma in the industrialized world has increased significantly in recent decades. Exposure to indoor allergens produced by dust mites, furry pets, rodents, cockroaches, foods and molds is a major driver of asthma morbidity and allergic sensitization. In recent years, multiple research studies have highlighted the role of exposures to allergens as well as other factors in determining health outcomes of allergic individuals, and indicate that the causal relationship between exposure and health effect may be far more complicated than previously assumed. This presentation provides a summary of relevant findings of the newest peer-reviewed studies of allergen and endotoxin exposures, health effects of allergen exposure itself, as well as co-exposures with environmental pollutants and endocrine disruptors. Topics addressed will include latest results of the CDC’s National Health and Nutrition Examination Survey (NHANES), and other epidemiologic surveys conducted in schools and homes, occupational exposures in laboratory animal facilities and other work environments. The second part of the presentation focuses on effective allergen avoidance and remediation measures, to provide better tools and knowledge to the IEQ practitioner.

Carbon monoxide is one of the contaminants in homes that engenders the most concern. Programs that evaluate homes spend substantial effort evaluating carbon monoxide. Furnaces, boilers, water heaters, and ovens/ranges are common sources of carbon monoxide in the indoor environment. This paper presents results of carbon monoxide measurements from two studies that looked at homes that underwent energy efficiency upgrades as part of the U.S. Department of Energy’s low-income Weatherization Assistance Program (WAP). In the first study, carbon monoxide was measured in the flues of furnaces, boilers, and water heaters, in the outlets of ovens/ranges, and in the indoor ambient air. Measurements in the appliance combustion gases was done once while at the site, and indoor air measurements were done using dataloggers recording for about one week. In the second study the focus was only on measured indoor ambient air, also with measurements using dataloggers for about a week. The paper also includes a comparison of carbon monoxide before and after retrofits.

Cooking has been identified as a major source of contaminants of concern for health in residential buildings. Cooking pollutants can be significantly reduced by using range hoods that exhaust to outside, and range hoods are required in Indoor Air Qaulity standards, such as ASHRAE 62.2. However, previous field and laboratory studies have shown that the capture efficiency of range hoods varies widely - even at the same air flow. Currently there is no way for standard developers, designers or installers to specify better capture efficiency. Over the past couple of years LBNL has been conducting laboratory experiments to develop a test method to determine capture efficiency for residential range hoods so that they can be tested and labeled. This test method development has been performed in collaboration with a wide range of constituents, including range hood manufacturers, via the development of an ASTM test method based on the LBNL research. This papr summarizes previous capture efficiency experiments and describes the tracer-gas based test method that has been developed. This includes the laboratory testing procedures and test results for several range hoods. In the development of the test method the laboratory experiments included investigations of spatial and temporal variability in tracer gas concentrations. These were used to develop uncertainty analyses for the proposed test method that will be also be presented.

Cooking emissions have long been seen as an odour problem. However recent studies showed that particle matter is the main health risk of indoor air (Logue, 2013) and cooking can be a major source. Research by MacNeill in 50 Canadian dwellings indicated that 16% of the fine dust originates from indoor sources in the summer, increasing to 41% in the winter. Studies on range hood flowrate and design optimisation showed that there could be a signification reduction of PM2,5 due to cooking. Research in Dutch offices has shown that filtration of ambient air can reduce the indoor PM2,5 concentration significantly. This explorative study aims to quantify the exposure to PM2,5 in 4 Dutch dwellings with two different ventilation systems and with or without mitigation actions. With optical particle counters PM2,5 concentrations were determined in the living room/kitchen and a bedroom of 4 dwellings during a week. Two dwellings were ventilated by a natural supply and mechanical exhaust, and the other two with balanced ventilation with heat recovery. One dwelling used a standard G3 filter and the other an M6. In the dwelling with the M6 filter the effect of an optimised range hood was measured. The results of the cases are described in the paper.

As residential building codes and above-code programs move toward tighter homes with whole-house mechanical ventilation the reliability and homeowner use of ventilation systems become extremely important. As an example of building code direction and concerns, implementation of the 2014 Florida Building Code requirements for whole-house mechanical ventilation and air tightness testing were delayed by the state legislature. The 2014 Florida Residential Code requires whole-house mechanical ventilation be provided for any home with tested air leakage, expressed in air changes per hour at 50 Pascals (ACH50), of < 5, which is also the air leakage upper limit. Similar requirements from the IBC are being implemented in other states (air tightness requirements are stricter in cooler climates). Thus in most states that have adopted the IBC, new homes will be required to have mechanical ventilation systems. What happens when a system fails? Do occupants repair it? Are failures a common enough problem that this is a concern? If failures are a problem, are there steps code bodies can take to minimize risk to health and safety? Toward answering the above questions the Florida Solar Energy Center (FSEC), a research institute of the University of Central Florida, conducted a 21-home field study investigating the failure rates of whole-house mechanical ventilation systems installed in Florida homes over the last 15 years (12 of the 21 systems were installed in the last 3 years). Researchers conducted a survey to assess homeowner ventilation system awareness and maintenance practices. They also inspected and tested the ventilation system to assess its operational status, level of ventilation provided and likely reason(s) for any issues discovered. Homeowners surveyed felt ventilation was important for health, but many were unaware of how their ventilation system operated. Testing found only three of the 21 study homes (14.3%) had ventilation air flow close to the design level with the type of system specified. In two of these homes, the ventilation systems were turned off by the homeowner, so only one of 21 homes (4.8%) was actually receiving the expected ventilation as found. Only 12 of the 21 homes (57.1%) were found to have ventilation systems capable of operating. Issues identified included failed controllers and dampers, partially disconnected or crushed ducts, dirty filters, and poor outdoor air intake locations. The paper provides a summary of the study findings along with a discussion of the results and recommendations for improving whole-house ventilation system performance and reliability.

Combustion safety testing standards for residential retrofit have recently changed.  Additionally, there has been substantial alignment between standards and guidelines from different organizations, including NFPA, BPI, and ACCA.  This has been the result of a significant effort to include all stakeholders in the development of the new procedures. The changes have simplified the process while retaining the evaluation of those issues that are most likely to present problems to homes. These changes will impact practices for residential retrofit programs going forward.  This paper describes the changes that have been made, provides the ratiobale for these changes, and details the alignment between organizations that has occurred.  In addition, results from a field study and survey of combustion safety failures in retrofit homes, which were conducted as a part of a Building America project, will be discussed.

Today the U.S. housing industry is at a critical juncture in its ability to deliver homes that safely and effectively meet increasingly demanding performance requirements of homeowners and modern building codes. But the housing industry must learn to better manage real and perceived risks that can impact occupant health and comfort and building durability. It is clear from decades of applied research through the U.S. Department of Energy's (DOE) Building America program that many building energy efficiency and performance improvements will not be adopted by the market or industry standards if they increase the likelihood of IAQ problems. Furthermore, good IAQ and healthy home features have been shown to be powerful drivers for energy efficiency and improved home performance. In 2015, Building America published a new integrated strategy to address these challenges and opportunities. The Building America Research-to-Market Plan, including three integrated Building America Technology-to-Market Roadmaps, will guide Building America’s RD&D activities over the coming years, to tightly focus program efforts on solving three critical challenges, and on improving the ability of the housing market infrastructure to adopt innovations that address them. The three Building America Roadmaps include: A) high-performance, moisture-managed envelope solutions; B) optimal comfort systems for low-load homes; and C) optimal ventilation and Indoor Air Quality (IAQ) solutions (the “IAQ Roadmap”). This paper describes the Building America IAQ Roadmap in more detail and highlight progress to date. This roadmap seeks to guide RD&D and market engagement to ensure that the development of best practices, specifications, and improved industry standards (e.g., future editions of ASHRAE 62.2) account for the effects that the building and its systems may have on the health of occupants and the durability of the building, while minimizing energy usage. The roadmap provides detailed strategic objectives that focus on improving technologies and industry standards in three areas: 1) Targeted pollutant solutions that better control known indoor contaminants of concern, near their emission source(s), to allow for improved IAQ without increasing dilution ventilation requirements; 2) Smart ventilation technology solutions that optimize the balance between IAQ and energy and account for other variables that affect IAQ, such as occupancy, exhaust fan (e.g., dryer and range hood) operation, indoor and outdoor temperature, RH, and outdoor pollutant levels (e.g., ozone and particles); and 3) IAQ valuation that facilitates standardized, quantified assessments of home IAQ to encourage more informed and objective design decisions regarding IAQ measures.

In France, various controls and measurements are performed in order to assess the performance of ventilation system, such as visual controls, airflow and pressure measurements at terminal devices and ductwork airleakage measurement. Those tests are performed according to several protocols, which might conduct to different results with different uncertainties. In this context, 8 French organisms participate to the PROMEVENT program, which is supported by the French Ministry for Construction and ADEME (French Agency for Energy). It aims to make the practices more uniform and to improve ventilation systems inspection protocols for both single-family houses and multi-family dwellings. In order to test the reliability of those protocols, various measurements have been performed on 2 multi-family dwellings with humidity demand controlled ventilation system and 10 single-family houses with balanced ventilation with heat recovery systems. For airflow and pressure measurements at terminal devices, tests have been performed by different operators, with different types of material, on different types of terminal devices, on repeatability conditions and with different applications of the protocol. The same method has been applied for ductwork airleakage measurements, with also different ductwork preparation and different parts of the ductwork tested. The analysis of these different measurements points out the weaknesses of the protocols and/or the minimum specifications the instruments should achieve to assure reliable results. In particular, for airflow measurement at terminal devices, the position of the material around the terminal could induce very important errors if the material is not centered or not airtight with the wall around the terminal. Moreover, the type of material used may induce uncertainties due to the technology (not all technologies might be used with all types of terminal) and due to the material it-self (important impact of the correction with calibration data). For ductwork airleakage measurements, important differences of the results have been noticed with different obstructions of the ductwork at terminal devices. Results could also be different between a measurement performed in one time (one section) or in two times (the same section divided in two sections). Therefore, all the tests performed during these campaigns confirm the need for a unique and more reliable protocol. Those results are consistent with the results of tests performed during the laboratory campaign of the program. A new protocol will be proposed and tested during the next phases of the PROMEVENT project, including uncertainties evaluation for each type of measurement.

The paper 'The Zero Pressure Paradox' (Bink et al, 2015), explains the theoretical limitations and some practical issues of the zero pressure compensation method as used by a powered flow hood. It was shown that the needed pressure compensation for supply and exhaust are fundamentally different. Furthermore, based on published results from others and on our own unpublished results, we claimed that the measuring accuracy depends on the type of air terminal device and how and where the pressure to be compensated is measured in the instrument. To minimize these effects we developed the 'extended' zero pressure method. To follow up on this and for further clarification, this paper presents the evaluation of a large number measurements with a powered flow hood. Both measurements of supply and exhaust at a large number of grids are presented together with an uncertainty analysis of measuring ventilation.

Chamber, Air duct, and test house experiments were carried out in order to characterize performance of a new “green” air tracing technology. Chamber experiments measured tracer broadcast control and safety. Sensor experiments tested multi instrument precision and tracer-sensor performance in ducts and ambient space. Building experiments included air change rate measurements using both the new tracer and sulfur hexafluoride (SF6) tracer. In-duct ventilation air supply ratio was measured in real time using sensors located before and after the mixed air supply. Three-hour and 18-hour room measurements showed greater decay of LIPA tracer versus SF6. PID measurements showed good agreement between multiple continuous reading sensors over these time periods. Good safety, broadcast control, real-time sensing, and multi-sensor precision were demonstrated. The strengths of this new method over previous tracer technologies demonstrated in these experiments include the ability to rapidly measure changes in labeled air levels in real-time, using relatively low cost sensing instruments. Examples of uses for real-time air tracing include commissioning, test and balance air distribution systems and ventilation effectiveness surveys, as well as verifying exhaust systems performance and air leakage testing.

Considerable focus on intelligent building control has expanded interest in incorporating more sensors into buildings, including ones for measuring indoor air quality. In commercial buildings with automation systems, adding more indoor air sensing in more locations could enable more effective ventilation control through dynamic and spatial fine-tuning, helping to save energy, improve air quality, or both. But how necessary and how useful is adding more than one air quality sensor per mechanical zone in typical commercial buildings with air-mixing mechanical systems, given the accuracy of available sensors? We assessed two approaches for locating from one up to 10 sensors for measuring carbon dioxide (CO₂) and the sum of volatile organic compounds (ΣVOC) in typical offices. One placement approach was intended to determine the best possible performance, using optimal clustering of locations by their concentration profiles; the second simply sited each additional sensor in the mechanical system’s return duct and averaged readings. Each approach was assessed at three levels of sensor accuracy in four different office cases that combined high or low air recirculation rates and open or private layouts. The analysis was conducted within a Monte Carlo framework in which dozens of other parameters—including spatially resolved emission rates, air mixing parameters, schedule profiles, and envelope and wind characteristics—were varied for each case. The results indicated that, in an office environment with at least some mechanical air recirculation, concentrations are reasonably homogeneous within a mechanical zone. The spatial coefficient of variation (the spatial standard deviation normalized by the mean concentration) was almost always less than 20%, even when spatial emissions variability was highly elevated. The spatial variation that did exist was generally overwhelmed by sensor error when typical building grade sensors were modeled. The implications are that: 1) for typical office spaces served by a common air-based system with at least a small amount of mechanical air recirculation, a well-mixed model is a reasonable representation of the bulk air concentration (though not necessarily personal exposure); 2) attempting to capture spatial distribution is less important than improving sensor accuracy, and without better accuracy can actually increase network inaccuracy; 3) if using and maintaining better sensors is not possible, placing more typical building grade sensors in the return duct to provide redundancy can help reduce overall error.

This paper discusses two particular points of the buildings airtightness measurement method (EN ISO 9972:2015) in relation with the calculation of the combined standard uncertainty; Zero-flow pressure difference and Line of organic correlation. The zero-flow pressure difference is measured before and after the test in order to calculate the change of pressure caused by the blower door. Actually the zero-flow pressure difference fluctuates during the test in function of the wind and the temperature difference between outside and inside of the tested building. One could therefore consider that all measured values have the same probability of occurrence during the test (rectangular probability distribution) and adapt in consequence the way of calculating the ‘mean’ zero-flow pressure difference. The paper shows how it could be done and taken into account in the calculation of the combined standard uncertainty. The air flow coefficient and air flow exponent are generally determined using an ordinary least-squares regression technique (OLS). This is however generally not the most appropriate technique because there are uncertainties in both the measured air flow rates and the pressure differences. The paper shows how the line of organic correlation (LOC) could be used in order to take these uncertainties into account.

With better insulation of buildings, indoor air pollution is becoming a growing concern for human well-being and human health. Today there is no easy way to determine in real-time indoor air quality because of two main reasons. First, there are thousands of pollutants in indoor air with diverse impacts on human comfort, health and safety. Second, the concentration of these pollutants are generally very low (few ppb). In order to monitor Indoor Air Quality, one can use relatively low cost sensors that give an estimation of the amount of pollution in situ and in real-time but without discriminating harmful pollutants from non-harmful pollutants. It is thus difficult to give accurate advice to reduce the level of indoor pollution. Another way is to sample air and analyze the samples in laboratories with very sensitive but also expensive devices. The last case presents some drawbacks; it takes time, both for sampling (1 hour up to 5 days) and for analyzing (~2 weeks) before knowing if there is any indoor air problem. Then, if there is one, more air samples have to be taken and analyzed in order to identify and locate the pollution emission source and begin to look for a solution to prevent pollution. It is costly. French government estimated indoor air diagnoses cost at around 3,000 euros per school building; It requires a specialist operator to identify the pollution origin. Here, we propose a new way to perform fast, low-cost indoor air quality diagnoses at high added value in buildings by using an innovative photo-acoustic analyzer. Thanks to its ability to measure: a) multiple individual chemical pollutants, b) in real-time c) and in-situ at ppb level. Indoor air diagnosis results can be obtained in few minutes only. In addition the emission sources of air pollution can be easily located. Thanks to the fact that this tool can be used by a non specialist and diagnosis results given in less than an hour, the diagnosis price can be divided by two compared to traditional indoor air diagnoses. The idea is also to save in a cloud contextual collected data during diagnoses (concentration of each monitored pollutant associated with the indoor environment) so that predictions (and some remediation solutions) of indoor air pollution can be made in similar environments.

Inhalation exposure to airborne particulate matter is closely linked to human health and comfort. National regulatory agencies utilize high-precision air quality instruments to monitor ambient air pollution; however, such instruments are often expensive and not practical for widespread building applications. Gathering indoor air data for building occupants can help address occupants' needs and improve public health. The main objective of this study is to validate the performance of a low-cost air quality sensor that monitors both particulate matter and total volatile organic compounds (TVOC). The present study involves experiments with three different environmental settings: 1) 240-L laboratory chamber, 2) one-person office, and 3) highly occupied cafeteria. A popular low-cost sensor, Samyoung’s Dust Sensor Module MDG 501S, was tested. The sensor had a small module with a particle counter and gas sensor inside. The low-cost sensor was validated with laboratory grade sensors: TSI AeroTrak Handheld Optical Particle Counter Model 9306 for particles and ppbRAE PGM-7240 gas sensor for TVOC. The laboratory chamber test results indicate that the low-cost sensor gives accurate readings for high particle concentrations (> 1000/m³) in the chamber. However, the accuracy and sensitivity decrease with lower concentrations that could be easily found in buildings. The sensor readings from the one-person office are highly correlated with occupancy, likely due to particle resuspension from flooring/clothing and skin shedding during occupancy. However, the sensor accuracy observed in a highly occupied cafeteria was the lowest and showed high variations in concentrations. In this environment, increased human activities seem to cause fluctuations in airflow and airborne particle concentrations, which could be difficult for the low-cost sensor to monitor. Nonetheless, the study results imply that the low-cost sensor system has potential applications in indoor air quality monitoring and pollutant control in occupied spaces.

The National Institute of Standards and Technology (NIST) constructed a Net-Zero Energy Residential Test Facility (NZERTF) to support the development and adoption of cost-effective NZE designs and technologies. Among the key objectives in designing the facility was the health and comfort of the occupants by providing adequate ventilation and reducing indoor contaminant sources. To improve source control, guidelines were implemented to utilize products with relatively low volatile organic compound (VOC) emissions. Indoor and outdoor concentrations of formaldehyde and 30 other VOCs were measured approximately monthly during two years of house operation. Measurements were taken under normal house operating conditions as well as with the ventilation system off and during elevated indoor temperatures. IAQ and energy measurements were used to validate the IAQ and energy results of a coupled CONTAM-EnergyPlus model. The validated model was then used to evaluate the IAQ and energy consequences of various source control and ventilation strategies. The results of this work demonstrate the need for appropriate product selection (source control) and mechanical ventilation in tight, NZE homes.

Radon is the second-highest leading cause of lung cancer, after smoking, in many countries, and associated with increased risk of leukemia and multiple myelomas have been documented. In an OECD survey of 30 countries, Ireland was found to have the eighth-highest average indoor radon concentration. In Ireland, radon results in over 56% of the population’s radiation exposure, accounting for up to 250 cases of lung cancer each year. There is no recognized threshold below which radon exposure presents no risk. Recent research shows that energy retrofitting of dwellings may lead to greater airtightness and increased indoor air pollutant concentrations, and there is a possibility that radon concentrations may also increase. A knowledge gap has been identified that the relationship, if any, between improved energy efficiency in buildings and indoor radon concentrations is not well understood. This study aims to fill this knowledge gap by collecting and analyzing existing literature-based data, and using this data as the basis for a complementary computational study of the implications for ventilation and for radon concentration of a number of energy efficient retrofit scenarios, relevant to the Irish building stock. A computational model will be validated against data from an experimental case study where radon measurements pre and post retrofit are being carried out. Once validated, simulations will contribute to the filling of a number of knowledge gaps identified, specifically (i) a lack of data on radon in buildings that have undergone an external insulation energy retrofit (ii) estimate radon concentrations in retrofitted buildings, incorporating a range of initial radon concentration scenarios and retrofit strategies (iii) provide recommendations for future policy surrounding the appropriate management of energy efficient retrofitting so that acceptable indoor air quality levels (to include radon) are maintained.

One in four Minnesota middle school students report that they have ridden in a car with someone who was smoking cigarettes in the preceding week (Minnesota Youth Tobacco and Asthma Survey, 2011), yet only eight US states have policies prohibiting smoking with youth in vehicles (www.no-smoke.org). This study expands on previous research by measuring ventilation rates and secondhand smoke particulate concentrations under a variety of conditions that affect passenger exposure. A total of 170 trials were conducted, including duplicate trials to determine reliability. The monitoring included continuous photometer measurements of fine particles (PM_2.5) before, during, and after a participant drove and smoked a cigarette. The instruments were installed in 3 to 5 locations inside the vehicle and 1 outside to measure and compensate for ambient air particulates. Carbon dioxide injection and decay were used to compute the ventilation rate and the PM_2.5decay rate was analyzed to determine the total removal rates that included ventilation and absorption. The monitoring was conducted for 3 vehicle types (sedan, mini-van, SUV), 2 driving speeds, 4 window positions, and multiple ventilation operating conditions over both summer and winter conditions. With windows closed and the vent fan on, the average PM_2.5 concentration during smoking ranged from 138 to 2,694 with an average of 1,020 ug/m³. After smoking stopped, it took from 4 to 25 minutes for the particulate level to decrease to the background level. When the activate smoking and post-smoking periods were combined, the passenger’s total PM_2.5 exposure averaged 165 ug/m³ * hr. The average exposure was 61% higher for city driving (30mph) than highway driving (60mph). The exposure in the rear seats compared to the front varied with window position. Overall, for about half of the trials, the SHS concentration was greater in the rear seats than in the front passenger seat. Opening windows greatly increased ventilation and reduced exposure levels. Opening windows just 2 inches reduced exposure by almost an order of magnitude and fully opening at least one window reduced exposure by a factor of 34.

The potential of natural ventilation to maintain acceptable air quality and thermal comfort in gymnasia was investigated via a case study and parametric modeling of a multisport facility at a university campus in the northeastern United States. Indoor temperatures at multiple locations were recorded for six days during August 2015 to verify the thermal accuracy of this model. Model and measurements differed on average by 0.5 degree C. A parametric modeling study considered the effect of a range of natural ventilation opening configurations, sizes. Simulations covered the summer months June, July, and August. Metrics for performance were hours during which at least the minimum ventilation flow rate required by ASHRAE Standard 62.1-2013 was maintained and hours during which temperature fell with an acceptable range as defined by the adaptive thermal comfort model in ASHRAE Standard 55-2013. Ventilation opening alternatives included increasing opening size or opening effective ventilation area of existing wall vents and adding rooftop vents.

With the focus on low energy and sustainable buildings today, building designers, engineers and researchers alike increasingly attempt to incorporate natural ventilation in innovative building practices. Despite the interests and collective effort, one key component of natural ventilation, the wind, has proven to be a difficult riddle to solve due to its unsteady nature. One difficulty with predicting wind-driven airflow is the determination of the amount of wind power available as a driving force for ventilation purposes. While it is common practice to assume the wind is steady and often hourly averages from TMY3 weather data are used for wind estimation, such assumption could be error prone due to variability of wind within the one-hour interval provided by the TMY3 data.To specifically investigate this issue, this study incorporates the much finer wind data from the National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) Automated Surface Observing System (ASOS), location-specific weather datasets with 1-minute resolution. Incorporation of such small time steps allows a probabilistic interpretation of how wind would have impact the nature ventilation design. Furthermore, computational fluid dynamics (CFD) was used to investigate the potential wind-driven ventilation flow rate based on this new statistics based wind data, and a comparison to the current state of the art estimation is provided.

In churches, intentional airing may be a measure to evacuate temporarily high levels of contaminants that are emitted during services and other occasions. Crucial contaminants include moisture and other emissions that may deteriorate and/or soil surfaces of paintings and other precious artefacts. Most churches do not have any mechanical ventilation system or any purpose provided openings for natural ventilation, but the ventilation is governed by air infiltration. Enhanced airing may be achieved by opening external windows or doors. Thus, models provided in energy simulation programs should predict this kind of air flows correctly, also in order to get a proper estimation of the total energy use. However there might be some limitations for airing in historical ancient buildings regarding moisture transfer, since at some conditions the outdoor air might be too humid. IDA-ICE is examined here and the models for humidity used in the program are investigated. In the present study, field measurements are performed for airing rate and moisture transfer in a historical church and the results are compared with modelled results from IDA-ICE energy simulation program.