Page 21 - Climate Control News May 2021

Indoor Air Quality
manual airing, which is not always possible. Often, windows are closed to avoid discom- fort caused by external noise from people, traffic and construction and extreme weather to prevent drafts.
However, without adequate ventilation, high concentrations of pollutants build up in- side the school, and microbes are likely to cir- culate in the environment.
“Adequate ventilation and indoor air quali- ty in classrooms cannot be achieved by split- type air[1]conditioners without the supply of fresh air leading to an accumulation of con- taminants,” Haddad said.
“A good ventilation system inside class- rooms, on the other hand, can ensure good air quality and thermal comfort, which can en- hance learning capacity and also protect stu- dents against the transmission of airborne diseases, like COVID-19.”
“GOOD VENTILATION IS AS IMPORTANT AS THE TEACHING MATERIAL IN A CLASSROOM.”
During the study, the research team in- stalled a demand-controlled ventilation sys- tem inside a classroom to monitor air quality and pollutants.
The system uses real-time feedback to reg- ulate indoor air quality in line with safe rec- ommended levels by adjusting the ventilation rate in response to occupancy numbers and pollutant concentration.
Once the air quality exceeds the school classrooms’ recommended thresholds, the ventilation system supplies fresh air and flushes out polluted air based on measured air quality in the classroom.
“Demand controlled ventilation with air extraction removes excessive heat and stale air and allows fresh cool air to enter the class- room and maintain indoor air quality and thermal comfort,” Haddad said.
“It utilises both natural and mechanical ventilation systems and provides an effective opportunity for controlling indoor air quality in school buildings by adjusting airflow rates based on indoor air quality measures such as CO2, Total Volatile Organic Compound (TVOC) and thermal comfort parameters.”
Haddad said the study supports a growing case for developing specific health guidelines that consider the combination of indoor- based ventilation and thermal comfort need- ed specifically for schools.
Reset indoor environmental conditions for buildings
INTERNATIONAL IEQ EXPERTS Seema Bhang- ar and Raefer Wallis talk about the complexities of monitoring indoor air quality conditions.
There are a number of factors that affect in- door air quality: climatic conditions such as tem- perature and humidity, the environmental con- ditions outside, the number of people in the room, furniture, technical equipment, and the building construction materials.
It is the complexity of the subject matter that has kept Indoor Air Quality (IAQ) out of the spot- light, according to Seema Bhangar, senior indoor quality manager at WeWork in San Francisco.
“When it comes to energy, it’s easy to set a benchmark: you measure the consumption val- ue and then you set a target to reduce this val- ue. Air quality is a much more complex issue, and there are many different benchmarks,” Bhangar said outlining the difficulty in finding the right approach.
“That’s why almost every company has an en- ergy manager, but hardly any of them have an air quality manager.”
These principles need to be translated into ef- ficient actions. But that requires the right tools.
“Technology has evolved at an incredibly rapid pace over the past few years,” Bhangar said.
“The possibility of measuring, digitalizing, processing, and visualizing things has arrived.”
Welcome to the world of Raefer Wallis. For 15 years, the qualified architect has been working on indoor air quality standards, and from his work has developed the international RESET standard.
“Air quality is not a do-it-yourself issue. It’s far too complex for that,” Wallis said.
He explains that there are so many different variables, some of which are actually contradic- tory —for example, how do you ventilate a room properly if the air outside is polluted?
In this case, solutions implemented without be- ing rooted in data might not be very effective.
In Western countries es- pecially, he said monitoring air quality indoors is largely done through “guesstimat- ing,” i. e. using a broad rule of thumb guideline.
Architect and RESET CEO, Raefer Wallis.
“It’s like a doctor who pre-
scribes a treatment without
being able to make a reliable diagnosis,” he said.
Wallis is therefore in favour of intelligent, au- tomated systems—which he also applies him- self. “Most people don’t know that suitable tech- nology has been around for a long time,” he said.
RESET uses the data recorded from sensors mounted on the walls or installed in the ventila- tion system. This is an area in which Wallis also works with ebm-papst, who offer not only fans with certified sensors, but also a platform for processing the data.
With the sensor data, the air quality can be analysed in real time and subsequently opti- mized with the help of the platform.
Wallis said this technology doesn’t require a major investment.
“The devices that we work with came onto the market in 2008 and have been designed as smart solutions since 2016. They are now sophisticated, quick to install, and cost-effective.”
RESET is the world's first sensor-based and performance-driven data standard and certifi- cation program for the built environment. Par- ticularly in cities with high levels of air pollution, air quality has long been an important issue; globally, the issue has come into focus, especially due to the Coronavirus pandemic.
Receiving
RESET
Certification is based on passing both a site audit and a data audit that con- firms compliance with RESET air limits for at least three consecutive months. Here, values for levels of particulate mat- ter, volatile organic com- pounds, carbon dioxide, temperature and relative humidity are included in the assessment.
LEFT: When it comes to air quality there are so many different variables.
CLIMATE CONTROL NEWS MAY 2021
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