Personalized Environment

Duration 7/2015 - 6/2016
Responsible Prof. Dr.-Ing. Sabine Hoffmann
Team Sabine Hoffmann, Katharina Boudier, Mathias Kimmling
Project type Drittmittelprojekt (Industrie) / Feldstudie

Over the past years thermal comfort research proved that having control over your ambient environment highly contributes to the satisfaction of building occupants. In open space offices it is almost imposible to give such individual control to people. The concept of Personalized Environment uses local devices which people can control according to their personal preferences.

The following systems of Personalized Environment are used in the Living Lab smart office space as well as in field studies:

1. A heated and cooled office chair

When turning on the heating function, the contact temperatures of the chair’s seat and back increase slightly and heat losses of people’s back and pelvis are reduced. Back and pelvis belong to those body parts that highly influence thermal sensation and comfort under cold conditions. Generally speaking the heating function is perceived as very comfortable on cold days.

The cooling function uses the increased circulation of air around the skin to increase convective heat transfer. In addition, latent heat transfer happens when the humidity of the skin evaporates due to the air movement.

2. Footwarmer

Although the use of a heated office chair allows to reduce the room temperature during the heating period, a cooling down of extremities, especially of feet, is noticeable if air temperature drops below 21 °C. Hence a footwarmer complements the heated chair in winter and allows for lower room temperatures while maintaining comfort.

3. Table top fan

Under hot conditions the head reacts strongly to heat. Air movement around the face increases heat tranfer to the environment and enhances thermal comfort.


The above mentioned devices need only little energy for operation. Their effect is based on providing or dissipating heat exactly where the body’s sensitivity is highest. The approach of a Personalized Environment not only increases thermal comfort but makes energy savings in buildings possible as the local devices reduce the necessary power of the HVAC systems.


Hoffmann, Sabine and Katharina Boudier. 2016. "A new approach to provide thermal comfort in office buildings: A field study with heated and cooled chairs." In Proceedings of Indoor Air Quality Ventilation & Energy Conservation in Buildings (IAQVEC), Incheon Songdo, Republic of Korea, October 2016. Best Paper Award.

Boudier, Katharina and Sabine Hoffmann. 2016. "Heated and cooled chairs for office use." In Proceedings of The Fifth International Conference on Human–Environment System (ICHES), Nagoya, Japan, October/November 2016.

Boudier, Katharina and Sabine Hoffmann. 2015. "Komforterhöhung und Energieeinsparung im Büroumfeld durch Klimastühle." In Tagungsband Bauphysiktage: Bauphysik in Forschung und Praxis, Kaiserslautern, Germany, Oktober 2015.

Boudier, Katharina, Massimo Fiorentini, Sabine Hoffmann, Raghuram Kalyanam, and Gergios Kokogiannakis. 2016. "Coupling a thermal comfort model with building simulation for user comfort and energy efficiency." In Proceedings of the Central European Symposium on Building Physics (CESBP) and BauSIM, Dresden, Germany, September 2016, 481–487.