Jorn Toftum

Jorn Toftum
Technical University of Denmark | DTU · International Centre for Indoor Environment and Energy

MSc, PhD

About

159
Publications
46,033
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
5,911
Citations
Additional affiliations
June 2018 - present
Technical University of Denmark
Position
  • Professor

Publications

Publications (159)
Article
ClimApp was developed to assist individuals in reducing the risk of exposure to thermal stress and to supply the user with individualized advice and recommendations. The tool integrates several human thermal models and heat indices with the local weather forecast and goes on to provide users with a prediction of their thermal stress based on their...
Article
Full-text available
This paper presents a critical review of studies addressing the effects of window views, daylighting, and lighting on occupant behavior, perception, performance, and well-being. A systematic search in the Scopus database was performed in November 2021 and yielded 515 hits. Seventy-six studies were selected according to the following criteria: i) pa...
Chapter
In this work, we investigated occupant’s thermal disposition in mixed-mode offices. Thermal disposition can be described as a person’s self-assessment of his/her own thermal sensitivity. Classic field studies on thermal comfort were conducted in mixed-mode offices located in Florianópolis (Brazil). Occupants manually controlled the mixed-mode strat...
Article
Thermal comfort is fundamental to indoor environmental design and operation as well as indoor thermal environment evaluation. This paper has reviewed the historic evolution of thermal comfort research during the last century using a systematic approach and a particular focus on adaptive thermal comfort studies. A large number of published articles...
Article
Visual comfort plays a central role in building occupants’ comfort, well-being and productivity. It is therefore fundamental to meet the occupants’ visual and lighting needs, carefully accounting for the room layout, usage and activities. In this framework, physiotherapy centres constitute a peculiar case since they are occupied by therapists and p...
Article
Full-text available
Thermal experience and thermal exposure are important aspects of thermal adaptation. However, the dynamic effects on thermal adaptation of thermal experiences and thermal history are not well understood. Migrants' long-term thermal adaptation process when transferring from Hot Summer and Cold Winter (HSCW), Hot Summer and Warm Winter (HSWW), and Se...
Article
Thermal models and indices integrated into a mobile application could provide relevant information regarding thermal stress and strain to the general public. The aim of the current paper is to validate such a mobile application, ClimApp, to the users need in the heat. ClimApp combines weather data with personal user data, thermal models and indices...
Article
Full-text available
By considering the importance of providing proper indoor environment conditions for occupants and also due to energy costs, one of the solutions for indoor local air-conditioning is Personalized Ventilation System (PVS). In this paper, the occupants’ thermal sensation was experimentally studied for body segments that are mostly affected by the PVS....
Article
Full-text available
Earlier studies have shown that low Correlated Color Temperature of lighting (CCT) may induce a warmer thermal sensation than high CCTs at the same ambient temperature. The current study investigated if the association between CCT and thermal sensation would persist when subjects worked on computers, were exposed for longer duration and when the st...
Article
Full-text available
One of the common local thermal discomforts that happen in an indoor environment is draught. Because of the importance of draught, many studies have been carried out to develop equations to calculate the draught rate. But because these equations are obtained from experimental tests in narrow experimental windows, their accuracy under wider environm...
Article
Full-text available
High-quality data on indoor climate and energy collected in buildings is required to deepen our understanding of building performance. The aim of this work was to investigate the relationship between the indoor and outdoor climate in Danish residential buildings. Field data was collected in 45 apartments from April 2019 to November 2020. Internet o...
Article
Full-text available
Migration between different climate regions may change people’s thermal experience and their thermal adaptation. However, few studies have explored the thermal adaptation process and the suitable indoor thermal environment of migrants. In this study, we conducted a long-term tracking comparative experiment on thermal adaptation of migrants moving f...
Article
Full-text available
This paper describes the functional development of the ClimApp tool (available for free on iOS and Android devices), which combines current and 24 h weather forecasting with individual information to offer personalised guidance related to thermal exposure. Heat and cold stress assessments are based on ISO standards and thermal models where environm...
Article
Full-text available
Occupants' thermal sensitivity influences comfort temperature, thermal comfort models, and building energy simulation. To date, a universal thermal sensitivity estimate (i.e. 0.5/°C), the so-called Griffiths Constant, has been widely used to estimate comfort temperatures. However, recent field evidence indicates that the constant is actually a vari...
Conference Paper
The aim of this work is to define profiles of the indoor climate in Danish multifamily residential buildings. Measurements of indoor temperature, relative humidity and CO2 concentration were conducted every five minutes for more than a year in 45 apartments using internet of things sensing devices. Cluster analysis was employed to derive the indoor...
Article
Clothing insulation is a key parameter to assess thermal comfort and is one of the most difficult parameters to estimate in field studies. The recent ASHRAE Global Thermal Comfort Database II contains a large sample of clothing insulation in addition to a wide range of other thermal and contextual parameters. However, the database does not provide...
Conference Paper
Full-text available
By considering the importance of providing proper indoor environment conditions for occupants and also due to energy costs, one of the solutions for indoor local air-conditioning is Personalized Ventilation System (PVS). In this paper, the occupants' thermal sensation was experimentally studied for body segments that are mostly affected by the PVS....
Article
Not many studies regarding comfort in physiotherapy centers are present in literature. These facilities host both therapists and patients, who can have different age and health status and perform different activities. For this reason, the assessment of indoor environment can be difficult, and models available in technical standards and in the liter...
Conference Paper
Full-text available
One of the common local thermal discomforts that happen in an indoor environment is draught. Because of the importance of draught, many studies have been carried out to develop equations to calculate the draught rate. But because these equations are obtained from experimental tests in narrow experimental windows, their accuracy under wider environm...
Conference Paper
High-quality data on indoor climate and energy collected in buildings is required to deepen our understanding of building performance. The aim of this work was to investigate the relationship between the indoor and outdoor climate in Danish residential buildings. Field data was collected in 45 apartments from April 2019 to November 2020. Internet o...
Article
A simplified modelling framework for the prediction of the indoor environment, energy use and socio-economic consequences of improving air quality and temperature in school buildings is suggested. The framework combines established models for infiltration and different modes of ventilation to estimate yearly distributions of the classroom temperatu...
Conference Paper
Full-text available
Air pollution can damage heritage collections. This study examines the air quality performance in one store with mechanical ventilation and in another with semi-passive climate control. Air pollution was measured with passive diffusion samplers during summer and winter. The atmospheric corrosivity was determined gravimetrically using copper, zinc a...
Conference Paper
Occupants’ behaviour is one of the most important factors to impact on indoor building environments and energy use[1]. Studies have shown that there is a gap between predicted and actual energy use due to poor consideration of the occupants’ behaviour[2,4]. The objective of this study is to improve understanding of occupants’ behavior and describe...
Article
This paper presents an experimental study that evaluated the effects of three different non-uniform types of clothing ensembles (Type A: short-sleeve shirt, T-shirt underwear, men’s briefs, straight trousers, socks, shoes; Type B: long-sleeve shirt, T-shirt underwear, men’s briefs, straight trousers; and Type C: long-sleeve shirt, men’s briefs, str...
Article
Recent years have seen considerable interest amongst building professionals and researchers in describing occupant behaviour. This has led to the development of models of adaptive behaviour to improve the accuracy and realism of building energy and indoor environment simulations. The objective of this study was to go beyond the typical behaviour mo...
Conference Paper
Full-text available
The effect of indoor environment parameters specified in national and international standards on simulated energy use of an educational spaces were assessed. Standards considered included those of EN, ISO, ASHRAE and ISHRAE. Eight different climatic locations were considered. Energy use to maintain IEQ parameters according to the highest category,...
Conference Paper
Full-text available
In this work, we aim to investigate occupant’s thermal disposition in mixed-mode offices. Thermal disposition can be described as a person’s self-assessment of his/her own thermal sensitivity. Classic field studies on thermal comfort were conducted in mixed-mode offices located in the city of Florianópolis (Brazil). Occupants manually controlled th...
Article
Adsorbent materials can be used for the removal of organic acids from air in storage rooms with heritage collections. The organic acid removal efficiency of two commercially available activated carbon air-filters were tested in situ in two unoccupied stores with densely packed collections. One filter was designed for outdoor type pollutants (Filter...
Article
Quality of the indoor environment has become an important parameter to account for in new and existing buildings due to the increasing number of people spending most of their time indoors. Generally, the design and evaluation of indoor environments in buildings rely on appropriate guidelines and recommendations. National and international IEQ stand...
Article
Physiotherapy centers represent a special environment since different activities are performed by the occupants, i.e., therapists and patients, who might have very different ages, metabolic rates, health status and clothing, as well as perform various types of treatment. In this framework, this study aims to provide an original contribution to the...
Article
The preservation of heritage collections in storage largely depends on the air quality conditions. Uncontrolled airflow transports unconditioned air into the building. Lowering the air exchange rate in unoccupied storage facilities is therefore essential to ensure acceptable climate conditions for the preservation of collections, while at the same...
Article
Full-text available
Non-optimal air temperatures can have serious consequences for human health and productivity. As the climate changes, heatwaves and cold streaks have become more frequent and intense. The ClimApp project aims to develop a smartphone App that provides individualised advice to cope with thermal stress outdoors and indoors. This paper presents a metho...
Article
Existing general explicit mass transfer models for volatile organic compound emissions have been validated against experimental results from small test chambers. This study compared emission rates predicted by such models to observations from homes, large test chambers and full scale experiments. The comparison revealed that the examined explicit e...
Article
Building performance simulation (BPS) tools need valid emission models to quantify the effects building generated pollution has on indoor air quality (IAQ) and energy demand. Predictions from existing emission models for volatile organic compounds have been shown not to correspond well with real world observations. This study aimed to approximate t...
Article
Personal Comfort Models (PCM) build on state-of-the-art methods to predict individuals’ thermal comfort responses based on occupant input and indoor environment measurements. Such models use machine learning and internet of things (IoT) to learn personal comfort requirements and integrate them into control systems for indoor environments. However,...
Conference Paper
Full-text available
One of the prevalent models to account for thermal comfort in HVAC design is the Predicted Mean Vote (PMV). However, the model is based on parameters difficult to estimate in real applications and it focuses on mean votes of large groups of people. Personal Comfort Models (PCM) is a data-driven approach to model thermal comfort at an individual lev...
Article
Full-text available
One of the prevalent models to account for thermal comfort in HVAC design is the Predicted Mean Vote (PMV). However, the model is based on parameters difficult to estimate in real applications and it focuses on mean votes of large groups of people. Personal Comfort Models (PCM) is a data-driven approach to model thermal comfort at an individual lev...
Article
Correlated Colour Temperature (CCT) of lighting may affect not only occupant visual perception, but also other indoor environment perceptions, such as perceptions of the thermal environment or the air quality. This study aimed at quantifying the association between CCT of white LED lighting and subjective perceptions and performance at operative te...
Article
Full-text available
Recognizing the value of open-source research databases in advancing the art and science of HVAC, in 2014 the ASHRAE Global Thermal Comfort Database II project was launched under the leadership of University of California at Berkeley's Center for the Built Environment and The University of Sydney's Indoor Environmental Quality (IEQ) Laboratory. The...
Article
Full-text available
Models are increasingly used to estimate and pre-emptively calculate the occupational exposure of airborne released particulate matter. Typical two-box models assume instant and fully mixed air volumes, which can potentially cause issues in cases with fast processes, slow air mixing, and/or large volumes. In this study, we present an aerosol disper...
Article
This short communication to the Editor is completely devoted to a recent paper published by Broday et al. (2017) in which a comparative analysis of methods for determining the clothing surface temperature is reported. Contrarily to what our colleagues have found, we will demonstrate that the algorithms reported in ISO 7730 and ASHRAE 55 Standards f...
Article
The current study aims to elucidate in greater detail the dermal uptake of nicotine from air or from nicotine-exposed clothes, which was demonstrated recently in a preliminary study. Six non-smoking participants were exposed to gaseous nicotine (between 236 and 304 μg/m3) over 5 h while breathing clean air through a hood. Four of the participants w...
Article
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...
Article
Full-text available
Six males clad only in shorts were exposed to high levels of airborne di(n-butyl) phthalate (DnBP) and diethyl phthalate (DEP) in chamber experiments conducted in 2014. In two 6 h sessions, the subjects were exposed only dermally while breathing clean air from a hood, and both dermally and via inhalation when exposed without a hood. Full urine samp...
Article
Benzophenone-3 (aka BP-3, oxybenzone) is added to sunscreens, plastics and some coatings to filter UV radiation. The suspected endocrine disruptor BP-3 has been detected in the air and settled dust of homes and is expected to redistribute from its original sources to other indoor compartments, including clothing. Given its physical-chemical propert...
Conference Paper
Full-text available
Today, face-to-face meetings are frequently replaced by video conferences in order to reduce costs and carbon footprint related to travels and to increase the company efficiency. Yet, complaints about the difficulty of understanding the speech of the participants in both rooms of the video conference occur. The aim of this study is to find out the...
Article
In this preliminary study we have investigated if dermal uptake of nicotine directly from air or indirectly from clothing can be a meaningful exposure pathway. Two participants wearing only shorts and a third participant wearing clean cotton clothes were exposed to environmental tobacco smoke (ETS), generated by mechanically “smoking” cigarettes, f...
Article
Organophosphates are used in a wide range of materials and consumer products and are ubiquitous in indoor environments. Certain organophosphates have been associated with various adverse health effects. The present paper reports mass fractions of organophosphates in dust samples collected from 500 bedrooms and 151 daycare centers of children living...
Article
Outdoor air delivery to buildings is an important parameter in the assessment of pollutant exposure indoors. Detailed and well controlled measurements of air exchange rates (AER) and interzonal airflows in residential environment are scarce. We measured the outdoor AERs in up to six rooms in five dwellings across four seasons using active tracer ga...
Conference Paper
Full-text available
When designing buildings and space conditioning systems, the occupant thermal comfort, health, and productivity are the main criteria to satisfy. However, this should be achieved with the most energy-efficient space conditioning systems (heating, cooling, and ventilation). Control strategy, set-points, and control dead-bands have a direct effect on...
Article
To assess the influence of clothing on dermal uptake of semi-volatile organic compounds (SVOCs), we measured uptake of selected airborne phthalates for an individual wearing clean clothes or air-exposed clothes and compared these results with dermal uptake for bare-skinned individuals under otherwise identical experimental conditions. Using a breat...
Conference Paper
Full-text available
Six volunteers spent 6 hours in an exposure chamber on 2 separate occasions during which the air contained elevated levels of DnBP. For both sessions, volunteers were only clad in shorts, facilitating the air-to skin transfer of DnBP. In one of the sessions, the volunteers breathed clean air from an airtight helmet, restricting exposure to the derm...
Article
Full-text available
Fundamental considerations indicate that, for certain phthalate esters, dermal absorption from air is an uptake pathway that is comparable to or larger than inhalation. Yet this pathway has not been experimentally evaluated and has been largely overlooked when assessing uptake of phthalate esters. This study investigated transdermal uptake, directl...
Article
To investigate whether acoustical refurbishment of classrooms for elementary and lower secondary grade pupils affected teachers' perceived noise exposure during teaching and noise-related health symptoms. Two schools (A and B) with a total of 102 teachers were subjected to an acoustical intervention. Accordingly, 36 classrooms (20 and 16 in school...
Article
Full-text available
There is great energy-saving potential in reducing variable air volume box minimum airflow set-points to about 10% of maximum. Typical savings are on the order of 10%–30% of total HVAC energy, remarkable for an inexpensive controls set-point change that properly maintains outside air ventilation. However, there has long been concern whether comfort...
Article
Exposure to ultrafine particles (UFP) may have adverse health effects. Central monitoring stations do not represent the personal exposure to UFP accurately. Few studies have previously focused on personal exposure to UFP. Sixty non-smoking residents living in Copenhagen, Denmark were asked to carry a backpack equipped with a portable monitor, conti...
Article
The indoor environment in a Danish prison was evaluated based on measurements made during the summer season of temperature, relative humidity and carbon dioxide, as well as through carefully conducted surveys among the inmates. The temperatures in the cells were high and well beyond common levels in Danish buildings. The mean CO2 concentrations wer...
Article
Field studies suggest that the availability of adjustable thermostats, operable windows and other controls has a positive impact on comfort, the incidence of building related symptoms and productivity. This laboratory study was designed to further investigate how having or not having control over the thermal environment affects human responses to t...
Conference Paper
Full-text available
The objective of this study was to analyse operative temperature drifts and occupant satisfaction with thermal environment in office buildings utilizing embedded radiant heating/cooling systems. Three office buildings were investigated: Town Hall in Viborg, Denmark (floor area 19400 m 2), IDOM, Madrid, Spain (16000 m 2), TiFS, Padua, Italy (2200 m...
Conference Paper
Full-text available
This talk will present results from chamber experiments, currently in progress, in which lightly clothed (only shorts) human subjects are exposed for six hours to elevated air concentrations of DEP (~ 150 ug/m3) and DnBP (~ 50 ug/m3). In preliminary experiments, subjects followed a restricted diet and avoided the use of personal care products over...