4. July 2023

Part Two: Two-way feedback – anew approach to interactions

From: Smart office buildings – curse or blessing? Human needs and “smartification”

In part one of this series of articles, we learned about the relevance of two-way communication between people and technology for a well-functioning efficiency-comfort optimization. At present, there is a lack of suitable channels that inform people in the building about the effects of their behavior.

Possible strategies to improve energy saving behavior

In the following graphic from the Wuppertal Institute and the EBZ Business School (Fig. 1), strategies are categorized according to their potential for behavioral change and energy savings.

Figure 1: Effectiveness of different energy saving strategies based on the results from the explorative research (Source: “Development of a strategy to support the energy saving behavior of users in office and administrative buildings”, Wuppertal Institute and EBZ Business School)

Direct feedback from technology to the people who use it is just one of many strategies for influencing energy-saving behavior (see Fig. 1). It was precisely this that was identified by the interviewees on the Schindler Campus as a particularly relevant missing element. In the following examples, we therefore address various feedback options and energy transparency via monitoring systems. 

The perceived indoor temperature / energy transparency

The perceived indoor temperature is essential for the comfort in a room. At the same time, however, this perception is individual and thus falls into the efficiency-comfort problem already described. While one person likes to leave the window open at 16°C, the neighboring room is heated to 23°C. Neither an open window nor 23°C should be technically excluded, otherwise comfort suffers. However, neither is necessarily energy-efficient. If the users were now informed live about the amount of energy they can influence with their individual behavior, they could take over this part of the responsibility and make a reflected and conscious decision. With little effort, live representations of energy consumption can today be created in order to make the effect of one’s own behavior tangible.

The automatic sun protection / decision transparency of algorithms.

“‘Why is this damn blind coming down again now?’ I ask myself and rush to the switch to stop the descending blind. My colleague does the same. Every day, this scenario repeats itself at least once, but usually several times. For reasons that seem inexplicable to me, the automatic system starts at the slightest ray of sunlight, sometimes if there isn’t even any sun visible at all. When the sun later shines full force into our office, the blinds stand still. I have already tried several times to deactivate the automatic system in order to be able to decide for myself when I want to have sun at my workplace and when the sunlight is too intense or dazzling. Unfortunately, this remained unsuccessful. I have absolutely no understanding for the process behind this automatic. I even wonder if there is any deeper meaning or rudimentary intelligence behind it at all.”

This example illustrates very well the consequences of not taking human needs into account in the process. Lack of understanding and resistance are the result.

In fact, a very simple algorithm is used in the building described in the above quote. More modern solar shading systems take into account the outdoor and indoor temperature, the occupancy of the room in question, and the actual glare of the sun when deciding to lower and raise the blinds. Nevertheless, the more complex the algorithm, the less transparent the “behavior” of a blind becomes to the occupants of the room. So in addition to the “energy transparency” already described, in order to be able to make conscious and reflected decisions, there is also the need to make the automatic decisions comprehensible. It must be made understandable why something is happening in the room (in this case, the reasons for lowering/raising the blinds) in order to increase acceptance or generate it in the first place.

Algorithms that learn individual preferences are also conceivable nowadays. If the lowering of the sun protection is always manually overridden, as in the case mentioned above, it should fail to occur. If the sunshade is later manually lowered again, a learning system could differentiate situations based on various input parameters (e.g., the position of the sun) and thus follow specific preferences more and more precisely. Such user feedback loops could be part of future studies, but at present it is not yet possible to make any statements about possible improvements in satisfaction. 

Ventilation / approaches to user assistance

“‘There’s a draft’ …once again I’m annoyed that my colleague has pulled open the window and an unpleasant stream of cold air is passing me by. I don’t mind letting fresh air in from time to time, but leaving the window open forever, and preferably even wandering away from the workplace during this time, gets on my nerves. It’s inexplicable to me how one can JUST sit in a cold and drafty room. It’s not as if I wasn’t already familiar with this phenomenon from my school days…some prefer constant intense ventilation, others crowd around the heating to avoid freezing completely. Especially in the depths of winter, there were always endless discussions here, not always on a friendly and understanding basis. When I look at the facts objectively, however, I ask myself what would be a suitable solution to this problem? Because one thing is clear, fresh air is needed. But a building in which the ventilation works automatically and the windows cannot be opened at all? I have also had this experience and can say that I was not happy with this approach. A uniform temperature in summer and winter, no direct contact with the outside environment for the ears and nose, no authentic perception of the weather and a constant draft from the air conditioning system are very unpleasant and frustrating in the long run. So it seems to me that you have to come to terms with your colleagues, have discussions and agree on compromises. Because this much is certain: Individual offices in which everyone can have their own individual air conditioning and ventilation are definitely not conducive to good collaboration and collegial exchange.”

Let’s look at indoor air quality. CO2 as an odorless gas is perceived by most people only belatedly and indirectly through concentration difficulties and headaches, but it is both an energy efficiency and productivity killer. Various devices have been developed in recent years, primarily to bring the viral load under control, but also to promote good indoor air quality. Prominent among these is the “climate kit” as described in the above-mentioned study by the Wuppertal Institute and the EBZ Business School.” [This climate assistant] is called “Piaf” and measures the air quality in the room. In addition to the CO2 value, the room climate assistant also records the temperature and relative humidity and signals [via pleasant chirping, as explained by the author] when the level of healthy well-being drops due to reduced air quality and ventilation should be provided”,* according to a press release from 2019. But also simpler systems with LED rings or similar can be very effective to draw attention unobtrusively to the correct ventilation times (open window / close window).

Such systems, which support people and enable them to behave consciously, can be found under the term “technical assistants”. They support their human counterparts with certain functions, but do not necessarily actively intervene. Thinking a little further, even highly efficient and technologically advanced buildings could benefit from the cooperation of their users. From an energy point of view, it is easy to understand that mechanical ventilation (with fans) requires more energy than an open window when the outside temperature is mild. To leverage this potential, people on site need to be involved and provided with the necessary information about building technology. After all, who is aware of how much electrical energy, for example, the ventilation system requires for the fans alone and at what outdoor temperature the recovered heat exceeds this necessary electrical energy?

A rule of thumb value: Compared to window ventilation, the operation of a ventilation system with heat recovery only makes sense from an energy point of view below 17°C (4°C difference to the indoor temperature). The same applies in summer: Above about 30°C, the ventilation system with heat recovery should be used from an energy efficiency perspective and the windows should remain closed.
If you want to implement this in your office, you should check beforehand whether the ventilation system can be switched off on a room-by-room or tenant-by-tenant basis, or whether it does so automatically when the windows are opened. Otherwise, there will be a “double” waste of energy.

A good communication channel from technology to people can also cover the described use case “manual window ventilation instead of mechanical system at mild outside temperatures” and thus raise further efficiency potential. At the same time, it remains an individual decision whether this additional activity is worthwhile or laziness wins out after all.


The examples mentioned show that with regard to the automation of heating, cooling and ventilation systems, there is considerable potential in terms of energy efficiency and satisfaction of the individuals using them. The focus here is on feedback from technology to people in terms of live energy consumption, explanation of algorithmically made decisions and involvement in the actual automation task. In the next article in this series, we will focus on flexible office space utilization, user-centric operations management and satisfaction feedback.