Discussion seven: Clotilde and Jan


Clotilde Pierson, a PhD student at Université Catholique de Louvain, interviewed Jan Wienold by Skype on 24th April 2019. 

Clotilde (CP): So, first question, Jan: briefly, what is your research about? Even though I know J 

Jan (JW): My research is mainly about visual comfort in buildings and the perception of environments which are mainly lit by daylight. 

CP: OK. I would like to know how you got to the situation in which you are today and what you did before becoming a scientist at the LIPID lab (EPFL). So, we can start for instance with your studies: what did you study? 

JW: I was studying mechanical engineering. And from the first time, I was very intrigued by renewable energies. I always wanted to work on something which improves the sustainability of either the built environment or the energy supply 

CP: So what did you do after you study to put that into actions? 

JW: First of all, at the end of my university time, I focused on renewable energies. My diploma thesis was about solar desalination and power generation. Then I started working in an engineering office which actually implemented solar concepts into buildings. There, I was working on a European research project on solar heating and cooling, so I continued that topic. 

CP: How long did you work in that company? 

JW: Around two years. And then, I changed to the Fraunhofer-Institute for Solar Energy Systems, continuing working on these topics in the group "Solar Building". I worked from the beginning on optimizing buildings and their façade for reducing the energy demand and providing a high comfort at the same time.

And then, at one point, I took over a European research project from my former boss, who left the institute, about the impact of different shading devices on daylight performance including the visual comfort aspect and glare. This was the first time I was exposed to that field. 

CP: So, this was the first time you worked on glare! And how did you happen to do this PhD on discomfort glare? 

JW: I think if you want to recap how I came into that, there is another step. Because this project was just touching a bit the glare but it was mainly about daylight.

But there was a key situation at Lux Europa, I think it was in 1997. I was discussing with Martine Velds at that time (now Knoop) about her studies on glare and she was so enthusiastic about her studies! I had done some experiments just with shading devices, but not really with subjects so much. This discussion with her gave me the impulse to do studies on glare. 

CP: So you were going to the conference to talk about your project on daylight? 

JW: Actually I cannot remember to be honest - this was in 1997! 

CP: Martine then gave you the will, if I can say it like this, to look into glare a bit more? 

JW: She gave me the impulse. We were discussing a lot during the conference and she was very enthusiastic. She explained to me that there were so many open points, so many things were not clear in that field that I was intrigued to go more into that. It was really this one situation causing me to think “Maybe it is a good idea to do something in the field of glare!”

Then I tried several times to apply for a European project on improving the glare evaluation. The third trial was successful when we included it in a project where the main goal was to develop a new controller for shading devices considering the human perception on glare. And since there were no reliable glare metrics available, the development of a metric which can be used as a control variable for the controller was one task of this European project. This project was called Ecco-Build. 

CP: So you did it at Fraunhofer? 

JW: Yes, I did it at Fraunhofer. 

CP: And who was your supervisor? 

JW: My main supervisor was Andreas Wagner from the University of Karlsruhe, and my co-supervisor was Jens Christoffersen. But, since the PhD-work was embedded in the European project, I received feedback from many experts, for example Marc Fontoynont from ENTPE and Nicolas Morel from EPFL. 

CP: Did you design the project? Or you just used it to do your PhD? 

JW: I created that project, and the decision of making a PhD out of the results was born within that project. My main goal was to improve the glare metrics. To make a PhD out of this topic, that was a later decision. It was not the other way around, since I did not have a PhD position at Fraunhofer ISE. For me, it was like “I want to work on this topic”, and then, at one point, I was saying “OK, this is so much stuff, I make a PhD out of that”.

I had not a typical PhD position like at a university, I had a normal researcher position. So, I did this research within my normal working time working for the project, and this was the scientific core of the thesis. Writing the thesis, this I did after work in my "free" time. And I had also a sabbatical of three months when I could concentrate to write the thesis. 

CP: How long did the project last? 

JW: The project started officially, I think, in 2002 until 2006. It was a four years European project. Afterwards, it took me a while to write the things together in a thesis J 

CP: The next question is: After the PhD project, did you do any other projects at Fraunhofer? 

JW: In general, for my work, I had always projects in parallel. It was never just working on one topic: I had many projects. And these projects were not only in the field of lighting!

I also worked on the energy optimisation of buildings, and I had several projects, for example on zero energy buildings. To mention two of my largest projects:

  • the first one was the building of the headquarters of the Fraunhofer in Munich where I optimised the double skin façade of a natural ventilated high-rise building. The daylighting part was a small one compared to the thermal comfort optimisation
  • the other big project I had was a Zero Energy Building in Seoul where I was the project leader for the whole energy concept. The main goal was to reach zero energy in that specific climate of Seoul, where you have a very cold winter and an extreme humid and warm summer during which dehumidification is a huge issue. Daylighting was also part of the concept, but played a minor role in the whole project.


CP: OK! So when and why did you decide to quit Fraunhofer and change to go to EPFL? I guess this is the next step, right? 

JW: Yes, I decided to come here at the end of 2013, but I moved in 2014. The reason was mainly to experience work in a different environment, and to focus more on research and on education. At Fraunhofer, we did very applied research for the industry.  So my focus shifted towards research. But the core driver was to change workplace and environment at one point in life! 

CP: Did you teach, did you have teaching experience before arriving at EPFL? 

JW: Not at university! I gave guest lectures, but not on a regular basis. 

CP: On which project(s) did you start working at EPFL? Was it mainly PhD students supervising, or did you have your own research project? 

JW: Yes, at the beginning, it was mainly PhD students supervising. 

CP: More generally now, do you consider that your research area, so discomfort glare and daylighting, was a choice of your own or of others? I mean: where you purposefully going into that direction or was it because of going from opportunities to opportunities? 

JW: This is hard to answer…As I mentioned before, my core interest was having sustainable energy supply or sustainable buildings. But at one point, I realised that the façade is one of the key aspects for the energy flow into the buildings.  And indoor comfort is one of the main drivers for the use of shadings and therefore influences the solar energy entering. Thus, having a good comfort is essential to have a low energy demand, because if the people are not happy they will use their façade in a way that it's not optimised for the energy. And this started my interest to go into that topic!

I found the overall topic so interesting that I stayed in the visual comfort area. But I was not starting from the beginning on the daylight topic, simply because I was not exposed to that during university time or previous projects.

I wouldn’t say I slipped into that but I encountered at one point that it is an important aspect that I was super interested in. And I still am! 

CP: And was there a turning point, at which you went from energy to comfort, in your career? Or was it more a slow transition from one to the other? Maybe the discussion with Martine at the conference? 

JW:  Yes, this was a very important point. This discussion that I had with her was, I would not say a turning point in my career, but it was a very important discussion which changed my direction into that. 

CP: And if you had to mention some people who inspired you in your career, could you say who and why? It might be from anywhere! 

JW: Well, inspired I was definitely from Martine, through that discussion in 1997. Also the early work on glare from Guth and Hopkinson inspired me. I was always wondering why there was not so much work done on glare from daylight in the 80s and 90s. And this lack of research encouraged me also to work in that field. 

CP: Turning to the teaching activity, how much and about what do you teach? 

JW: I teach one course in the fall semester about comfort in buildings. 

CP: And these are graduate, postgraduate students? 

JW: It is a master course. 

CP: And how many PhD students do you supervise at the moment? 

JW: That’s a good question, I have to count! Giorgia (Chinazzo) has just finished, Angelina (Katsifaraki) last year. So at the moment, it is Kynthia (Chamilothori), it is you, it is Sneha (Jain), Geraldine (Quek), and Stephan (Wasilewski). Five running PhD students! 

CP: I can guess the answer, but what are their research topic? You don’t have to answer for me (working on the influence of culture on discomfort glare perception from daylight), and for Kynthia, I know as well (working on the influence of façade patterns and daylight variability on our perception of architectural spaces). But what about Geraldine? 

JW: She is working on the "interface" or "grey area" between good and bad contrast. As you know there are positive and negative aspects of contrast, and they are interacting. So, she's exploring this area more. 

CP: Nice! And then Sneha? 

JW: Sneha started recently in February and she is looking at interactions with discomfort glare. 

CP: She still doesn't have a particular factor on which she will focus then? 

JW: There are ideas…To look at the spectral influence on the glare perception for example. Or age, or eye colour,…You know that there are many! 

CP: Indeed! And at last, Stephen? 

JW: Stephen is working on efficient methods for temporal and spatial glare analysis, improving simulation methods. 

CP: And regarding research, what would you say is the greatest lighting achievement in your research field, so in glare research or in daylighting research to be broader? 

JW: For me, the greatest achievement for the moment is that we managed to establish, for the first time, a standard on daylight in Europe. So that people are aware that daylight is important and that it is an important aspect to consider in the design process of buildings. So the greatest achievement is that daylight is more recognised to be an important aspect in in the built environment. 

CP: For the energy, the comfort, and also the health of the occupants I guess? So for all the factors that are influenced by daylight? 

JW: In general that daylight is important and it has all these aspects. Of course, health is also included. 

CP: And if you have to say why we need lighting research, or daylighting research, what would you say? 

JW: There are so many things which are unknown at the moment! If you speak about statistics, our "correlations" are explaining the data only partially, not fully. And of course, as researcher, we try to get more knowledge about why the results are like this. So that in the end, we can have better models to predict comfort in buildings. 

CP: And what would you imagine in lighting research in the future? What main discovery, or main step, do you think we will achieve in the future? So for instance, do you think we will manage to have an efficient blind control system based on small glare sensors? 

JW: I would phrase it more broadly: I envision better and more intelligent façades which provides better quality and a higher amount of daylight than it is in the state-of-the-art.

The key needs of the people are to have a large amount of daylight at the workplace or wherever they are. The best would be to have this situation glare free, and with a good view to the outside, and, at the same time, limiting the solar gains in summer, not to have overheating. That's the core goal of a good façade in the future.

Also this facade should adjust to the personal needs, which we know differs from person to person. So, the façade system should consider the individual preferences of the users as well. If it is automatic, or if it is individually controlled or a self-learning algorithm or other approaches, this I don't know. I don’t know what is the best solution for that, or in which direction it will go - there are many solutions. 

CP: What part of research do we need to improve in the lighting field now? Is it the statistics, or the methodology, or the hypotheses, the measurements…? What is still lacking a bit in our field of lighting research, according to you? 

JW: This is a very important question, and it drove me a lot in the last years. In my point of view, the research in the last years is mainly focused on producing very fast results without focussing on the thoroughness.

One thing is that that the measurements are correct. Honestly, if you look closer on published papers using HDR imaging, I would say more than 50% have technical problems such as pixel overflow. These problems make the results unreliable. In some other cases the methodologies or statistics are not appropriate…But this sounds so negative! 

CP: Maybe by developing more collaborations, we could improve that. Because we cannot be experts in everything, right? So maybe, we need more collaborations in the lighting field? 

JW: Yes, I think collaborations definitely help to improve that. It is a very simple thing: Four eyes see more than two eyes only! And it's the same for the research, the more people who are really involved in the research, the better the quality of the research. I'm totally convinced about that!

But this conflicts with the need of having many publications. This kind of research (thorough studies involving several partners) takes simply longer. To have a good research output takes much longer than it is expected at the moment from many universities…I think that the policy should change in the future, that not the amount of publications is what counts, but the high quality is. 

CP: And also, probably, making the data more open access, or sharing the data so that people can reproduce your analyses and check the results. I think it is also important. 

JW: Yes, indeed. 

CP: What do you think is your biggest achievement during your career? Any publication, Evalglare, the DGP? What would be the one you are the most proud of? 

JW: That’s a good question! Of course, I am proud of Evalglare, even though I just programmed it as a vehicle to develop a new glare metric. I wanted to have a flexible tool where I can quickly change features and to have some extra outputs which were not available in existing tools. That’s why I programmed it by myself. That it became a tool which is now used by so many people makes me definitely proud!

But I think I am really proud being part of the group having worked on the European standard on daylight. 

CP: When was the first time that you either heard about the daylighting standard or was aware of it? How did it started, this idea of a daylighting standard? Where you involved from the beginning? 

JW: I was part of the German standardization group for daylight since several years, and I heard from the activities that there was an initiative to launch a European standard on daylight. I was one of the delegates of the German standardisation group at that time. 

CP: Do you remember around when it started? 

JW: I think…Actually, there was a very first initiative which was rejected, and this was already in the mid 2000's or so. This project started, if I remember correctly, 2010 or 2011. It’s such a long time ago, I cannot really remember! 

CP: Back to your research: do you remember the last time you were surprised by research results? Something that you did not anticipate, if it ever happened… 

JW: I was surprised that culture has no influence! J Because I expected it would! 

CP: Yes, I did too! It was unexpected, that’s true. Moving to conferences: is there any particular location or events that you remember particularly fondly? 

JW: Yes, definitely. This was actually at the Lux Europa in 2005 in Berlin. I can still remember like it was yesterday! After I had my presentation, Ne'eman (Dr Eliyahu Ne’eman) was talking to me and congratulating me personally about the research. And this made me really proud until now. This was a special moment! 

CP: Wow! And what was the presentation about? 

JW: It was the first presentation about DGP. The presentation was called “Towards a new daylight glare rating”. And Ne’eman was in the audience. But I realized it only afterwards that it was him! J 

CP: Haha, good! Still about conferences, what advice would you give to someone about to give their first presentation at a conference? What could they do to make it a good presentation? What would you recommend? 

JW: To have a clear structure about the presentation, which follows also the structure of the research: presenting the objectives and the methodologies, and then the results. And not to be afraid about the audience! 

CP: Well, I think that the part that we most fear is probably the questions from the audience at the end! Especially when you are a young researcher, you just started in the field, and you have to present something. Then there is this experienced researcher who asks a very difficult question to which you cannot answer… 

JW: Well, what I can say is: don’t be afraid about the questions afterwards, because this really enriches also the research. It's always good to listen to other opinions to consider for your next experiment or your next evaluation of the data. Even if it might be uncomfortable at the moment if it's a very difficult question, finally it helps improving the research! 

CP: The last topic, which is probably a very timely topic for you, is about work-life balance! Do you have any other interest besides daylighting? In other words, what makes you happy outside of work and what do you like to do in your spare time? 

JW: Much more things than I have time for! Besides family, I like any outdoor activities, like hiking. I did a lot of sport in the past, like triathlon and playing volleyball. 

CP: And how do you manage work-life balance? So do you get the time for those other interests? And do you have advice potentially to give about that? 

JW: Even though I think I don't have enough time to do everything, I think it's important to do several activities besides work. They make your mind clear, which helps you to be better at work again. For example, if you go running or you hike during the weekend on high mountains, then you don't think about glare or Zero Energy Buildings anymore! And this "reset" in mind helps you have new ideas and be fresher at work. You also have more output than if you work all the weekend, when you might get stuck and have no fresh ideas. These breaks always help to improve at work. This is what I can say from my experience. 

CP: And do you think you have a good life-work balance at the moment or that you should improve it? 

JW: I think I should improve it, I think I still work too long. Especially with this recent small new "add-on" in the family, I need to work less. 

CP: But I guess it is difficult to choose then what you don't do at work…Because you have several projects in parallel and you want to do them all, right? 

JW: Definitely, if I reduce my work, it will be always my own research, because the first priority is typically the supervision of the PhD students. I don't want to reduce the quality of the supervision, so if I reduce, it's my own research. 

CP: And what are your own projects right now? You just published the cross-validation study, do you have something else in mind? 

JW: I work on several things in parallel. The first thing that will be visible will be about glare and fabrics; either on the simulation side or on the perception side; both projects are going on in parallel. We will conduct soon user assessments with fabrics, and, on the simulation side, I have already published a model but there will be a journal publication on that as well.

Besides that, we work also on improving the calculation methods for the annual glare evaluation, especially since it's also part of the European standard. We need some more efficient methods to do that, and we probably also need an intermediate step before the new methods from Stephan (PhD student) will be available. 

CP: As a conclusion, what would be your best advice to a novice researcher, or a new PhD student, or any young researcher about to start a career in research? What would you advise them? 

JW: Be curious and always question your and the others’ results! 

CP: I agree! And I am trying to apply it as often as I can! 

JW: Well, I think you have that in your blood, so no worries! J 

CP: Haha! J Good, thank you Jan!

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