Master’s degree in civil engineering, 1972. Ph.D., Laboratory of heating and Air Conditioning, Technical University of Denmark, 1975. In the period 1972-1990 Research scientist at the Laboratory of Heating and Air Conditioning. Part time affiliated as product manager at Brüel & Kjaer 1978-1992. Senior Research Scientist, College of Architecture, Virginia Tech. in the period 1992-1993. Since 1993 until January 2004 Head of Research & Development at UPONOR-VELTA GmbH KG & Co., Norderstedt, Germany. Since January 2004 full professor in Indoor Environment & Energy at the Technical University of Denmark and director of the International Centre for Indoor Environment and Energy, Technical University of Denmark. Awarded the Ralph Nevins Award (1982), Distinguish Service Award (1997), Fellow Award (2001) and Exceptional Service Award (2006) from ASHRAE. Awarded the Medal of Honour from the German Engineering Society (VDI-TGA, 2005) and International Honorary Member of SHASE. The Society of Heating, Air-Conditioning and Sanitary Engineers of Japan. Vice president of ASHRAE and Honorary member of AICARR (Italian Society for HVAC).
Is active in several ASHRAE-CEN-ISO-DIN standard committees regarding indoor environment and energy performance of buildings and HVAC systems. Has published more than 350 papers including more than 60 in peer reviewed journals.
International Standards for the Indoor Environment- Where are We and Do they Apply Worldwide?
On the international level ISO (International Organization for Standardization, ISO EN 7730), CEN (European Committee for Standardization, EN15251, EN13779) and ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers, Standard 55, 62.1 and 62.2) are writing standards related to the indoor environment. This presentation will focus on the development of standards for the indoor thermal environment and indoor air quality. In the future, recommendations for acceptable indoor environments will be specified as classes. This allows for national differences in the requirements and also for designing buildings for different quality levels. This will require a better dialogue between the client (builder, owner) and the designer. It is also being discussed how people can adapt to accept higher indoor temperatures during summer in naturally ventilated (free running) buildings. Several of these standards have been developed mainly by experts from Europe, North America and Japan, thus guaranteeing a worldwide basis. Are there, however, special considerations related to other parts of the world (lifestyle, outdoor climate, and economy), which are not dealt with in these standards and which will require revision? Critical issues such as adaptation, effect of increased air velocity, humidity, type of indoor pollutant sources etc. are still being discussed, but in general these standards can be used worldwide.
Indoor Environment – Health Comfort and Productivity
People spend in industrialized countries more than 90 % of their lives in an artificial indoor environment (home, transportation, work). This makes the indoor environment much more important for people health and comfort than the outdoor environment. In typical office buildings the cost of people is a factor 100 higher than energy costs, which make the performance of people at their work significantly more important than energy costs. The task is to optimize indoor environmental conditions for health, comfort and performance while conserving energy, since more than one third of current global energy consumption is used to maintain indoor environments. Detailed field investigations of the indoor environment in hundreds of large office buildings in many parts of the world have documented that the indoor environmental quality is typically rather mediocre, with many people dissatisfied and many suffering from sick-building syndrome symptoms. Recent studies under laboratory conditions and in the field have shown a significant influence of the indoor environment on people’s productivity. Also studies on people sick leaves show a very high loss of work time and performance, which have significant economic consequences for companies.
The paper presents an update on today’s requirement for a healthy and comfortable environment. The paper will mainly be dealing with the indoor thermal environment and air quality. Several standards and guidelines are specifying requirements related to comfort and to health; but the productivity of people is not taken into account. Recent studies showing that comfortable room temperatures, increased ventilation above normal recommendation, reduction of indoor pollution sources and more effective ventilation increases the performance of people. The results indicate increase of productivity of 5-10 %. Also based on the laboratory studies a 10 % increase in dissatisfaction decreases the productivity with around 1%.
Applications of Embedded Radiant Heating and Cooling in Buildings
Alternatively to full air-conditioning heating and cooling may be done by water-based radiant heating and cooling systems, where pipes are embedded in the building structure (floors, ceilings, walls) or in the center of the concrete slabs in multi-story buildings. The present talk will discuss the possibilities and limitations of radiant surface heating and cooling systems. Differences in performance and application of surface systems compared to embedded systems are presented. Results from both dynamic computer simulations and field measurements are presented.
The paper shows that for well-designed buildings these types of system are capable of providing a comfortable indoor climate both in summer and in winter in different climatic zones. Various control concepts and corresponding energy performance are presented. To remove latent heat, these systems may be combined with an air system. This air system can, however, be scaled down with the benefit of improved comfort (noise, draught) compared to full air-conditioning. An added benefit can be reduced building height due to the elimination of suspended ceilings. Finally, surface heating and cooling systems use water at a temperature close to room temperature. This increases the possibility of using renewable energy sources and increasing the efficiency of boilers, heat pumps and refrigeration machines.
Are women feeling colder than men in air-conditioning buildings
Recently the international media like in USA, Canada, UK, Denmark, Germany etc. has been discussing the issue of differences between men and women regarding thermal comfort and the preferred room temperature.
Fanger (1982), Fanger and Langkilde (1975), and Nevins et al. (1966) used equal numbers of male and female subjects, so comfort conditions for the two sexes can be compared. The experiments show that men and women prefer almost the same thermal environments. Women’s skin temperature and evaporative loss are slightly lower than those for men, and this balances the somewhat lower metabolism of women. The reason that women often prefer higher ambient temperatures than men may be partly explained by the lighter clothing normally worn by women.
First, the primary reason is that we are overcooling buildings in summer, using enormous amounts of energy, and creating uncomfortably cold conditions for everyone. A study at Lawrence Berkeley National Laboratory found that average temperatures in office buildings in the U.S. are colder in the summer than in the winter (exactly the opposite of what they should be), and are actually lower than the minimums recommended by the standards. Existing international standards like ISO EN7730, EN15251 and ASHRAE 55 are based on the same basic studies described above. These standards do not specify different room temperatures for women and men when doing the same work and dressed in similar clothing. Contrary to what has been suggested, these standards are not devised exclusively for men. They are based on extensive laboratory studies of both men and women wearing the same clothing, engaged in the same activity, and exposed to a wide variety of thermal conditions (air temperature, surface temperature, humidity and air movement). Metabolic heat production was simply a proxy for the kind of activity. And while it is one of many variables used in an empirical formula, it is not an input to a heat balance equation, as one might find in a thermo-physiological model (which exists, but was not the basis for the standards). The primary reason is that we are overcooling buildings in summer, using enormous amounts of energy, and creating uncomfortably cold conditions for everyone.
How to meet the ventilation required in international standard in an energy efficient way
The present talk provides an overview and discusses the criteria used for specifying required ventilation rates in international standards like ASHRAE 62.1, ASHRAE 62.2, EN15251 and ISO 17772. The concept for estimating the required ventilation rate to obtain an acceptable indoor air quality is somewhat similar in the standards; but do result in quite different levels of ventilation. Increased ventilation rates will result in increased energy use. To reduce the ventilation rate the most effective way is to reduce the sources (low emitting materials, filtration of outside air). The talk will also present and discuss other ways to reduce energy use for ventilation by means of natural ventilation, improved ventilation effectiveness, demand controlled ventilation, use of air cleaning, personalized ventilation and heat recovery.
The influence of occupant behaviour on indoor environment and energy use in buildings
Technologies alone do not necessarily guarantee low energy buildings. Occupant behavior plays an essential role in the design and operation of buildings, but it is quite often oversimplified. Occupant behavior refers to an occupant’s movement and responses to discomfort, when his/her comfort needs are not met. Occupant behavior varies with time, space, individual, and is influenced by social context. It is stochastic, complex, and multidisciplinary. Having a better understanding and modeling of occupant behavior in buildings can improve the accuracy of building simulations and guide the design and operation of buildings. This talk highlights related behavior research at various institutes.
Can we take into account diversity when specifying requirements for the indoor environment?
Many studies show large individual difference regarding the preferred indoor climate (temperature, air velocity, ventilation). There are many other diversity factors like sex, race, age, culture, etc. that can have a significant influence on the preferred and/or accepted conditions for the indoor environment. Can we take such influence into account when designing buildings and building service systems? Recently the international media like in USA, Canada, UK, Denmark, Germany etc. has been discussing the issue of differences between men and women regarding thermal comfort and the preferred room temperature. Experiments show that men and women prefer almost the same thermal environments. Women’s skin temperature and evaporative loss are slightly lower than those for men, and this balances the somewhat lower metabolism of women. The reason that women often prefer higher ambient temperatures than men may be partly explained by the lighter clothing normally worn by women. This presentation will provide an overview of existing knowledge and discuss related issues.
Indoor Air Quality Association 1120 Rt 73, Suite 200 Mt Laurel, NJ 08054