Growing awareness of the importance of indoor air quality (IAQ) to human comfort and health is prompting changes in the way that the ventilation needs of built environments are managed.
Activities and processes within buildings themselves, such as washing, cooking and food consumption, can lead to negative impacts on indoor air quality by introducing pungent air particles or lifting humidity to levels that foster the growth of mould.
As noted by Sophi MacMilan, environmental scientist and CEO of the Vinyl Council of Australia, poor IAQ can cause a broad variety of health impacts which while mild, can still significant diminish the comfort of work efficiency of building occupants.
These range from non-specific symptoms such as headaches and fatigue to more serious ailments including respiratory issues and allergic reactions.
Such problems can cause major dilemmas for stakeholders in buildings such as office complexes, given that employers are required by law to provide safe workplace environments to their staff.
The obvious solution to improving IAQ is effective ventilation that provides consistent and unimpeded airflow through a given indoor environment, replacing stale air and flushing out unwanted particulate matter.
MacMilan notes that ventilation during time frames as brief as one to five minutes can be sufficient to completely replace all of the indoor air contained by a room without causing thermal mass walls to lose temperature, meaning that warmth can be retained during the winter months.
While the advantages of effective ventilation are demonstrable, reaping these benefits in many built environments can nonetheless pose a challenge as it can entail the repeated adjustment of multiple windows.
This is particularly the case when windows are situated in hard-to-reach positions, or in large-scale built environments such as office complexes or group residential facilities, which possess a considerable number of windows in multiple rooms that are impossible to manually adjust en masse.
Window automation systems could provide the solution to these difficulties by unburdening occupants of the need to make regular adjustments to windows themselves in response to shifting environmental conditions, as well as facilitating the control of windows in hard-to-reach locations.
Much of buzz surrounding building automation systems (BAS) has focused on their ability to improve the efficiency of built environments via control of HVAC and lighting by adjusting such systems in response to the presence of occupants, time of day and environmental factors.
BAS lends itself more readily to the coordination of HVAC and lighting because they are internal mechanical and electrical systems that are much easier to integrate into a computerized control set-up.
New methods are fast emerging, however, to facilitate the automation of windows as well. They do so via the installation of various forms of mechanical actuators that enable either BAS or homeowners themselves to remotely control their operation.
David Oliver of Assa Abloy said window control actuators play a particularly important role in enhancing ventilation control of certain buildings whose windows are located in elevated positions.
"Elevated window control systems can provide an ideal solution to controlling the ventilation needs of building with elevated windows," said Oliver.
The devices employ corrosion resistant chains to adjust windows to a variety of positions in order to cater to different outdoor weather conditions or ventilation needs.
Independent of automated control systems, the installation of elevated actuators can improve ventilation by facilitating the opening and closing of windows that might otherwise remain unadjusted due to their difficult location.
When incorporated into BAS however, actuator-installed windows have the potential to solve the ventilation needs of built environments in one fell swoop by automatically opening and shutting windows at given time intervals to ensure sufficient cycling of air throughout the day, as well as by adjusting them independently in response to external weather events.
This means building occupants can go about their business without having to concern themselves with making regular adjustments to windows, yet they can still remain confident that they will enjoy improved IAQ as a result of the work done on their behalf by the automated system.
Oliver notes that existing elevated window actuators can already come equipped with sensors that can respond automatically to external conditions, opening and shutting in response to key weather events such as rainfall.