Pawel Wargocki

Technical University of Denmark | DTU · Department of Civil Engineering

In this study, a respiratory infection-based outdoor air ventilation criterion was derived in the form of new ventilation equation that was applied to cases studies representing typical rooms in public buildings. The derived ventilation equation allows to calculate the required ventilation rate at a given probability of infection and quanta emissio...

Bedroom ventilation is crucial for providing good indoor air quality, which may contribute to achieving undisturbed sleep. This study presents a detailed characterization of bedroom carbon dioxide (CO2) profiles and ventilation during the heating season in Denmark. The measurements were made in a naturally ventilated (NV) semi-detached house, equip...

In the CleanSky 2 ComAir study, subject tests were conducted in the Fraunhofer Flight Test Facility cabin mock-up. This mock-up consists of the front section of a former in-service A310 hosting up to 80 passengers. In 12 sessions the outdoor/recirculation airflow ratio was altered from today’s typically applied fractions to up to 88% recirculation...

The Covid-19 pandemic has caused untold disruption and enhanced mortality rates around the world. Understanding the mechanisms for transmission of SARS-CoV-2 is key to preventing further spread but there is confusion over the meaning of “airborne” whenever transmission is discussed. Scientific ambivalence originates from evidence published many yea...

In the CleanSky 2 ComAir study, subject tests were conducted in the Fraunhofer Flight Test Facility cabin mock-up. This mock-up consists of the front section of a former in-service A310 hosting up to 80 passengers. In 12 sessions the outdoor/recirculation airflow ratio was altered from today’s typically applied fractions to up to 88% recirculation...

Human emissions of fluorescent aerosol particles (FAPs) can influence the biological burden of indoor air. Yet, quantification of FAP emissions from human beings remains limited, along with a poor understanding of the underlying emission mechanisms. To reduce the knowledge gap, we characterized human emissions of size-segregated FAPs (1-10 μm) and...

Humans are a potent, mobile source of various volatile organic compounds (VOCs) in indoor environments. Such direct anthropogenic emissions are gaining importance, as those from furnishings and building materials have become better regulated and energy efficient homes may reduce ventilation. While previous studies have characterized human emissions...

Many people spend most of their time in an indoor environment. A positive relationship exists between indoor environmental quality and the health, wellbeing, and productivity of occupants in buildings. The indoor environment is affected by pollutants, such as gases and particles. Pollutants can be removed from the indoor environment in various ways...

Sleep is essential for our health and well-being. Some research suggests that air quality influences sleep quality in bedrooms, but the evidence is limited. Research, until now, has focused on how indoor air quality affects health, comfort, and cognitive performance during waking hours. Less information is available on the levels of indoor air qual...

During the rapid rise in COVID-19 illnesses and deaths globally, and notwithstanding recommended precautions, questions are voiced about routes of transmission for this pandemic disease. Inhaling small airborne droplets is probable as a third route of infection, in addition to more widely recognized transmission via larger respiratory droplets and...

With the gradual reduction of emissions from building products, emissions from human occupants become more dominant indoors. The impact of human emissions on indoor air quality is inadequately understood. The aim of the Indoor Chemical Human Emissions and Reactivity (ICHEAR) project was to examine the impact on indoor air chemistry of whole‐body, e...

Building ventilation standards use indoor carbon dioxide (CO2) levels as a proxy for air quality, acknowledging that at typical indoor levels, CO2 itself is not a pollutant. By 2100, outdoor CO2 levels may reach 900 ppm. With current ventilation standards, that would nearly double the levels of chronic, indoor CO2 exposure, raising concerns for its...

Well-being in the built environment is a topic that features frequently in building standards and certification schemes, in scholarly articles and in the general press. However, despite this surge in attention, there are still many questions on how to effectively design, measure, and nurture well-being in the built environment. Bringing together ex...

Ammonia (NH3) is typically present at higher concentrations in indoor air (~ 10 - 70 ppb) than in outdoor air (~ 50 ppt - 5 ppb). It is the dominant neutralizer of acidic species in indoor environments, strongly influencing the partitioning of gaseous acidic and basic species to aerosols, surface films, and bulk water. We have measured NH3 emission...

This study investigated whether adjusting clothing to remain in neutral thermal comfort at moderately elevated temperature is capable of avoiding negative effects on perceived acute subclinical health symptoms, comfort and cognitive performance. Two temperatures were examined: 23°C and 27°C. Twelve subjects were able to remain thermally comfortable...

We present in this work some results from analysing the spread of Covid-19 in different countries and regions around the world and the potential relations with climate, geographical location, and GDP. While the situation remains dynamic, we believe this analysis has the potential to uncover certain underlying trends. We primarily intend the results...

In this study, we examined changes in EEG signals during the cognitive activity at different air temperatures and relative humidities (RH). Thirty-two healthy young people acclimatized to the subtropical climate of Changsha, China, were recruited as subjects. They experienced four air temperature levels (26, 30, 33, and 37 °C) and two relative humi...

A cross-sectional study was conducted in Singapore to investigate whether buildings refurbished to attain the Green Mark (GM) standards present measurable improvements to indoor environmental quality (IEQ) that are also manifested by the occupants with respect to their level of satisfaction and health symptoms. Comparative analyses were performed w...

The data from published studies were used to derive systematic relationships between learning outcomes and air quality in classrooms. Psychological tests measuring cognitive abilities and skills, school tasks including mathematical and language-based tasks, rating schemes, and tests used to assess progress in learning including end-of-year grades a...

Climate models imply that by 2100 atmospheric CO2 levels could exceed 900 ppm. At these levels, subscribing to current ventilation rates would lead to indoor CO2 levels ≥1,400 ppm, possibly impacting our physiology and other responses. We ran a randomized, within-subject study with 15 participants to examine the physiological effects of 2,5 hour ex...

Fourteen Green Building (GB) certification schemes were reviewed to examine the parameters they used to assess indoor environmental quality (IEQ). Ninety different parameters were identified. They were classified into four major IEQ components defining the thermal, acoustic and visual environments, and indoor air quality (IAQ). For the thermal envi...

Previous work examining the condensed-phase products of squalene particle ozonolysis found that an increase in water vapor concentration led to lower concentrations of secondary ozonides, increased concentrations of carbonyls, and smaller particle diameter, suggesting that water changes the fate of the Criegee intermediate. To determine if this vol...

Fisk summarizes the findings of 10 studies investigating whether increased carbon dioxide (CO2) concentrations, with other factors constant, influence perceived air quality, health, or work performance of people. Concentrations of CO2 in occupied buildings exceed outdoor concentrations because CO2 is a product of peoples' metabolism. Indoor CO2 con...

The present paper reports a meta-analysis of published evidence on the effects of temperature in school classrooms on children's performance in school. The data from 18 studies were used to construct a relationship between thermal conditions in classrooms and children's performance in school. Psychological tests measuring cognitive abilities and sk...

This research focused on investigating thermal comfort in naturally ventilated (NV) dormitory buildings in hot summer and cold winter (HSCW) climate zone in China. A field study was conducted during the summer of 2016 in Changsha, located in HSCW climate zone. The occupants reported subjective thermal perception using questionnaires and ambient env...

The overall objective of the International Energy Agency project, Energy in Buildings and Communities Annex68“IndoorAirQualityDesignandControlinLow-energyResidential Buildings,” ¹ is to provide a scientific basis for optimal and practically applicable design and control strategies for high IAQ in residential buildings. An obstacle for close integra...

Currently, there are studies which show the separate effect of the local discomfort parameters such as the draught and radiant thermal asymmetry. However, no studies have been conducted to find out the combined effect of the before mentioned two discomfort parameters on human performance. In order to fill this gap, a 17 months experiment was perfor...

This article is an accidental publication. It was accepted by the Guest Editors in charge of the peer-review process without the authors' final consent. The Guest Editors have given their approval for this decision.

Indoor environmental quality (IEQ) has become an important component of green building certification schemes. Whilst green buildings are expected to provide enhanced IEQ, higher occupant satisfaction, and less risks for occupant health when compared with non‐green buildings, literature suggests inconsistent evidence due to diverse research design,...

Indoor environments have a large impact on health and well-being, so it is important to understand what makes them healthy and sustainable. There is substantial knowledge on individual factors and their effects, though understanding how factors interact and what role occupants play in these interactions (both causative and receptive) is lacking. We...

A two‐week long intervention study was performed in two classrooms in an elementary school in Costa Rica. Split‐cooling air conditioning (AC) units were installed in both classrooms. During the first week, the air temperature was reduced in one classroom while in the other (placebo) classroom the fans were operated but no cooling was provided. Duri...

This paper summarizes the results of HealthVent project. It had an aim to develop health-based ventilation guidelines and through this process contribute to advance indoor air quality (IAQ) policies and guidelines. A framework that allows determining ventilation requirements in public and residential buildings based on the health requirements is pr...

This paper summarizes the results of HealthVent project. It had an aim to develop health-based ventilation guidelines and through this process contribute to advance indoor air quality (IAQ) policies and guidelines. A framework that allows determining ventilation requirements in public and residential buildings based on the health requirements is pr...

Is sleep becoming so much scarcer than ever before because people do not realize the importance of sleep for health and well-being? All over the world, digital communications now mean that contact with work continues after hours and during weekends and that “friends” are no longer just the people we meet regularly, but the many more we contact regu...

The effects of emissions from cement-based and cement-ash-based mortar slabs were studied. In the latter, 30% of the cement content had been replaced by sewage sludge ash. They were tested singly and together with either carpet or linoleum. The air exhausted from the chambers was assessed by means of odour intensity and chemical characterization of...

The aim of the present study was to extend the knowledge on the suitability and performance of different ventilation retrofit solutions for school buildings located in a temperate climate. A unique approach was used, where four similar and adjacent classrooms in the same school unit located north of Copenhagen, Denmark, were retrofitted either with...

The purpose of this study was to examine whether exposure to human bioeffluents, at the levels recommended by the current ventilation standards, would cause any effects on humans. Ten subjects were exposed in a low-emission stainless-steel climate chamber for 4.25 hours. The outdoor air supply rate was set to 33 or 4 l/s per person, creating two le...

Conditions in which exhaled and dermally-emitted bioeffluents could be sampled separately or together (whole-body emission) were created. Five lightly-dressed males exhaled the air through a mask to another, identical chamber or without a mask to the chamber in which they were sitting; the outdoor air supply rate was the same in both chambers. The...

A major obstacle for integrating energy and indoor air quality (IAQ) strategies in the design and optimization of buildings is the non-existence of an agreed measure, which can quantitatively describes the IAQ and will allow the assessment of measures to improve energy performance. A complication to develop such an IAQ index is that hundreds of che...

Human subjects were exposed for 3 h in a climate chamber to the air temperature of 35 °C that is an action level, at which the working time needs to be diminished in China. The purpose was to put this action level to test by measuring physiological responses, subjective ratings and cognitive performance, and compare them with responses at temperatu...

This paper investigates the concern that green buildings may promote energy efficiency and other aspects of sustainability, but not necessarily the health and well-being of occupants through better indoor air quality (IAQ). We ask ten questions to explore IAQ challenges for green buildings as well as opportunities to improve IAQ within green buildi...

The road from science to practice was never a highway downhill. That is the case of 'climatisation' or 'air-conditioning'. Practice required " rules of thumb " , " calculation tools " , etc. to make life more 'fluid' for practitioners. Yet, if proper solutions cannot be without scientific explanations, every science advance affects the current cult...

Background: The annual burden of disease caused indoor air pollution, including polluted outdoor air used to ventilate indoor spaces, is estimated to correspond to a loss of over 2 million healthy life years in the European Union (EU). Based on measurements of the European Environment Agency (EEA), approximately 90 % of EU citizens live in areas wh...

Twenty-five subjects were exposed to different levels of carbon dioxide (CO2 ) and bioeffluents. The ventilation rate was set high enough to create a reference condition of 500 ppm CO2 with subjects present; additional CO2 was then added to supply air to reach levels of 1,000 or 3,000 ppm, or the ventilation rate was reduced to allow metabolically-...

To extend the results of a previous study on the effects of carbon dioxide (CO2) and bioeffluents on humans, the new study reported in this paper was carried out. The purpose of this study was to examine, whether exposure to CO2 at 5,000 ppm would cause sensory discomfort, evoke acute health symptoms, reduce the performance of cognitive tasks, or r...

The purpose of this study was to examine the effects on humans of exposure to carbon dioxide (CO2) and bioeffluents. In three of the five exposures, the outdoor air supply rate was high enough to remove bioeffluents, resulting in a CO2 level of 500 ppm. Chemically pure CO2 was added to this reference condition to create exposure conditions with CO2...

The purpose of this study was to examine whether exposures to CO2 in the range of 500ppm to 3,000ppm with and without bioeffluents influence cognitive performance. Twenty-five subjects were exposed in the climate chamber for 255minutes. Cognitive performance was examined by multiple tasks including proof-reading, addition, subtraction, text typing,...

The "ASHRAE Position Document on Filtration and Air Cleaning" provides Society members and other stakeholders with information on these technologies and their application. This column answers a few questions about the main positions and statements formulated in the position document (http://tinyurl.com/ashraeiaq).

The "ASHRAE Position Document on Filtration and Air Cleaning" provides Society members and other stakeholders with information on these technologies and their application. This column answers a few questions about the main positions and statements formulated in the position document (http://tinyurl.com/ashraeiaq).

The effects of bedroom air quality on sleep and next-day performance were examined in two field intervention experiments in single-occupancy student dormitory rooms. The occupants, half of them women, could adjust an electric heater to maintain thermal comfort but they experienced two bedroom ventilation conditions, each maintained for one week, in...

Objective of this paper is to examine whether the available epidemiological evidence provides information on the link between outdoor air ventilation rates and health, and whether it can be used for regulatory purposes when setting ventilation requirements for non-industrial built environments. Effects on health were seen for a wide range of outdoo...

The Building and Construction Authority Green Mark Scheme in Singapore encourages better indoor environmental quality for healthier workplaces for occupants. However, studies have shown that green buildings do not necessary ensure better indoor environmental quality. This case study aimed to compare the prevalence of sick building syndrome symptoms...

Both sleep and good indoor air quality are generally considered to be important for human health and well-being. In the present study, sleep quality and next-day performance were measured in identical single-occupancy dormitory rooms located in a quiet area North of Copenhagen. The 16 international students participating as subjects, half of them w...

The present study investigated how different ventilation system types influence classroom temperature and air quality. Five classrooms were selected in the same school. They were ventilated by manually operable windows, manually operable windows with exhaust fan, automatically operable windows with and without exhaust fan and by mechanical ventilat...

The effect of air quality on sleep was examined for occupants of 14 identical single-occupancy dormitory rooms. The subjects, half women, were exposed to two conditions (open/closed window), each for one week, resulting in night-time average CO2 levels of 660 and 2585 ppm, and air temperatures of 24.7 and 23.9°C, respectively. Sleep was assessed fr...

Experiments were conducted in late summer and winter with 80 young and elderly Danish subjects exposed for 3.5 hours in a climate chamber to the temperature increasing from 24°C to 35.2°C at a rate of 3.7K/h. Psychological and physiological measurements were performed during exposure and subjects assessed comfort and acute health symptoms. Thermal...

This paper reports an attempt to estimate the socio-economic effects of upgrading the indoor air quality in Danish schools to the level of Swedish schools. The OECD “PISA” score is used to quantify the effects together with the Danish Rational Economic Agent Model (DREAM). The following effects are taken into consideration: a) increased PISA score...

Guidelines for health-based ventilation in Europe are proposed. They take the premise in control of exposures to air pollutants indoors having both indoor and outdoor origin. Exposures are controlled through a double sequential approach, in which source control is the primary strategy while ventilation is the secondary strategy only after all optio...

Carbon dioxide (CO2) sensors that provide a visual indication were installed in classrooms during normal school operation. During two-week periods, teachers and students were instructed to open the windows in response to the visual CO2 feedback in one week and open them, as they would normally do, without visual feedback, in the other week. In the...

Associations between learning, ventilation mode, and other classroom characteristics were investigated with data from a Danish test scheme and two widespread cross-sectional studies examining air quality in Danish schools. An academic achievement indicator as a measure of the learning outcome was calculated from the scores of a standardized Danish...

This paper reviews and discusses various sustainable materials utilizing waste products with the focus on their properties having an impact on the indoor environmental conditions and indoor air quality (IAQ). Materials included in the review are selected considering the following aspects: sustainability, cradle to cradle perspective, application, t...

People spend a significant part of their life indoors mainly in the built environment (in public and residential buildings). In developed parts of the world, the proportion of time spent indoors can be as high as 80% to 90%. Many non-industrial buildings do not provide adequate conditions as regards indoor environmental quality especially indoor ai...

Thank you for giving us an opportunity to reply to the letter from Leyten and Kurvers (2013) concerning our recent paper on the effects of thermal discomfort in an office (Lan et al. 2011). Our experiment does not show which of several possibly driving factors caused our subjects to perform simulated office work about 10% more slowly when they felt...