Wall units
For facilities in which the occupants are given some control over their interior environment, such as commercial offices, the wall units’ ease of use is important. To many, the environmental controls can seem obscure. Beyond providing building occupants a better experience, installing intuitive controls saves the facility’s staff from having to answer calls from disgruntled people asking, “How do I turn the heat up (or down)?”
Similar to BAS software, some manufacturers undertake extensive usability testing for their wall units. In one system, this has led to a wall unit design with the simplicity and sophistication of a smartphone. To achieve this, the unit’s developers prepared and refined sketches of how the user interface might look and operate, then created an interactive prototype running on a tablet device. From this mockup, they closely monitored approximately 25 to 30 people with varying levels of building control experience using the system. The next stage of human-centred design involved installing beta test units in multiple real-world settings and recording how people interacted with the unit. For this particular product, refinements included:
- icon size and placement to more closely resemble a smartphone;
- reversal of temperature controls to simplify use for both right- and left-handed users;
- addition of navigation icons to help enhance user understanding; and
- zone of interaction tightening to eliminate dead zones on the unit’s touch screen.
These and other changes indicate the level of attention necessary to achieve a truly human-centred design.
Of interest to facility professionals, some wall units also offer advanced settings that include service tech for building commissioning, and system overrides. Such codes empower field technicians to work on the sensor right in the room without special equipment or access, which can help streamline initial building commissioning, along with service calls in the years to come.
Conclusion
In addition to the thousands of dollars per year a BAS can save a building owner, the systems have the added financial advantage of a short payback period. According to some estimates, building control retrofits and control strategies have a payback period of only three to four years.
When specifying a BAS, in addition to the system’s technical capabilities, considering one designed according to human-centred principles is crucial. This can help ensure the system is used. While a BAS manufacturer or delivery agent can explain what usability testing went into their system, the most effective way to know is to test the system’s ease-of-use for yourself.
Kevin Callahan is a product owner and evangelist for Alerton, a Honeywell business. He has 38 years of experience in the building control technologies field, including control systems design and commissioning, facilities management and user training. Callahan can be contacted at kevin.callahan@honeywell.com.
