The Internet is a valuable tool for business communications. Recent initiatives are using the net as a way of collecting information from building occupants to assess their reactions to the working environment.
The achievement of a comfortable environment for building occupants is one of the primary goals for building services. Occupant comfort can have a great impact on office productivity. Employees may stop working if environmental conditions (normally temperature) are in the extreme.

But occupants in large buildings, may view even a thermostat as too technical, especially as its adjustment could affect other occupants' comfort.

Furthermore, a temperature value such as 20°C, may seem technical or confusing to some occupants, and may bare little resemblance to how the person feels, or to the true temperature of the occupant's immediate work area, which may be some distance away from the temperature sensor.

These days, facilities managers have taken on the role of managing such environmental and plant settings often via a building energy management system (bems) because of the increased complexity of modern office buildings – particularly in large air conditioned environments. The environmental settings in occupied zones such as room temperature, humidity or fresh air intake are initially based on pre-occupied designed comfort default parameters and control schedules when the bems is commissioned.

Better control; greater efficiency
These design environmental default settings may or may not match the actual heat loads in each occupied zone. A mismatch in building services design and control with the actual environmental needs of the occupied zone (for example due to a change in office layout) often leads to the discomfort of some occupants. It may even lead to other ramifications such as ineffective use of energy, or oversizing, and sometimes costly design remedies such as plant retrofits and post-commissioning modifications must be applied.

Need for occupant feedback
Given this scenario, where the occupant has limited or virtually no direct control of their environment (a very typical situation especially in large open-plan buildings), occupants in slight discomfort may simply put up with it, or provide their own local solutions e.g. fan heaters, or additional clothing. Only in extreme discomfort would occupants make a formal complaint to the facilities management1.

Open-plan offices have added challenges2 to achieve comfort, particularly for individuals due to mass zoning of hvac equipment.

Occupant feedback can offer vital information to facilities managers and the bems on the occupant's actual comfort – as opposed to the attainment of, for example, room temperature set points by the plant. Occupant feedback could possibly avoid over-cooling or overheating of occupied zones and hence could lower energy usage.

Apart from the traditional complaint channels of occupant feedback mentioned above, there have been various research initiatives in the area of gathering occupant feedback for improvement of the built environment for post-commissioning purposes3 - 4.

These initiatives draw from the analysis of feedback data gathered using survey questionnaires. They can offer scores, which reflect the occupants' opinion about the building's indoor environment.

Recent initiatives have included the use of web browsers to offer the occupant the chance to comment on room temperature. They can then adjust temperature according to all responses collected – a sort of democratic voting for the preferred environment5.

BEMS and wap
Some bems manufacturers are investigating the use of browser-based virtual instruments such as thermostats for zone control. Building control interactivity with modern communication technology such as the Internet or wireless application protocol (wap)6 is becoming more prevalent in modern offices. This greatly increases the control paradigm possibilities available for occupants to give useful feedback for increased comfort control.

The R U Comfortable (Reading University Comfortable) environmental control project aims to introduce a novel browser interface, and possibly a fresh concept in occupant feedback and comfort control in the built environment via the bems.

Human comfort is a very complex research field which covers both physical (temperature, humidity, air movement, clothing etc) and psychological (mood, personal preferences etc) factors or sick building symptoms which may include a combination of physiological and psychological factors7.

The aim of our web interface is to try to establish more qualitative parameters. For example, temperature (too cold, too warm); humidity (too dry, too humid). These are associated with human perceptions, as opposed to quantitative values for example 20°C, 70% relative humidity, which are normally associated with artificial sensors.

Occupants in control
The basic concept of the RU Comfortable browser control interface is shown in Figure 1. The building occupant submits their opinions on how they feel about the immediate working environment for example too warm, too dry or any symptoms being felt such as dry eyes. The sliding scales relate qualitatively the severity of each environmental parameter. For example, if the occupant is slightly warm then he should slide the temperature bar (by sliding the grey triangle) mid way from the centre towards the right of the scale.

Once occupants have adjusted the parameters, they submit the comfort request through a web server using the office intranet. A fuzzy logic engine then translates each occupant's response and adjusts the hvac plant or other environmental actuators such as blinds to improve the environment based on these requests.

Net strengths
Using the Internet/intranet in this way has many advantages for occupants and building managers alike. Novel parameters and sick building symptoms are now quickly identifiable by the bems for example smell, headaches, dry eyes, fatigue.

These parameters may be used to control of other comfort factors such as humidity or fresh air intake.

This method allows better satisfaction and targeting of the occupant comfort as occupants become the human sensors, and have direct access to environmental controls.

This is also a multi-variable control. That is, there is adjustment of two or more plant parameters derived from occupant responses. For example, a response to stiffness could entail the increase in airflow rates, more fresh air intake and the resetting of supply temperatures slightly higher.

In modern office buildings networked pcs are common office equipment. Such pc facilities can offer the bems greatly increased numbers of human sensors – and they are cheaper than using dedicated room sensors to measure temperature, humidity, CO2 and its associated node and cabling cost. Furthermore, the total removal of dedicated room sensors may be a possibility, but will need to be investigated more cautiously as the R U Comfortable system may still require dedicated sensors as a broad reference for bems control purposes.

Future areas of study
Areas of study currently being investigated by Reading University and requiring more research include:

  • handling and adjustment of environmental parameters from occupant responses for large open-plan zones
  • total removal of zone sensors
  • the use of mobile phone and wap technology as an alternative to networked pcs.

Conclusion
The human is, of course, the ultimate sensor and target for building environmental control systems. This interface gives bems the ability to ask much wider ranging questions and gather more accurate feedback than would be possible with conventional sensing equipment.

An interactive web information and discussion forum has been formulated at http://www.eng.reading.ac.uk/occupantfeedback/ for readers to present their views on web-based occupant feedback and the R U Comfortable environmental control system.

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