Ever Felt Like the Air is Running out in the Room?
Outdoor air pollution has been a hot topic in public for quite a while due to the rising number of health symptoms and even deaths the industrial emissions have caused. The thing is that, while fighting the outdoor pollution, we forgot that people spend close to 90% of their time indoors, not outdoors. Indoor air pollution seems to be a very downlooked and now a rising topic in the field of air quality studies.
My Giant Leap project in 2017 is named "Customer benefit from Accurate HVAC Measurements", so part of my job is to reason in customer perspective the accurate measurements provided by Vaisala's sensors used in Demand Controlled Ventilation in buildings. The DCV works by measuring the indoor air quality and then controlling the ventilation accordingly. The research for indoor air quality has brought me to the topic of the effect of indoor air quality in people.
Indoor air quality is quite tightly linked to outdoor air quality. Due to inefficient building sealing, filtration and ventilation, many outdoor pollutants come indoors almost in the concentrations they appear outside. Indoor carbon monoxide, nitrous oxide, some Volatile Organic Compounds (VOCs) and many more come from outdoor sources and cause us health risks indoors as well as outdoors.
"The buildings in western countries at least are well sealed, so the outdoor pollution is well kept away from indoors". This might have crossed your mind, but not all indoor pollution comes from outdoor sources. If the building really is well sealed and the ventilation tightly controlled, the concentrations of hazardous substances in the air start to build up quite quickly. But where do these substances come from? We have our good ol' neighborhood pals radon, mold and other particulate matter, but what's even more downlooked at, in this time of energy efficiency savings by ventilation control, is carbon dioxide.
Usually indoors we people are the main cause of pollutants and what pollutant we produce the most is carbon dioxide via our respiration. Although CO2 being a gas in nature in concentrations around 400 ppm in the fresh outdoor air we breathe, it causes some interesting effects in higher concentrations on people even in normal everyday environments.
And the researchers have found some interesting results too. Remember when you sat in history class at school and felt like the air was running out? You almost fell asleep and after the class you couldn't recall anything the teacher had taught you. The researchers from Harvard's Center for Health and the Global Environment studied on how green buildings positively affect health and cognitive function. They saw people's cognitive function increase by 101% just by doubling ventilation from the recommended levels, decreasing VOCs from regular concentrations to outdoor concentrations and decreasing CO2 concentrations from 950 ppm to 500 ppm. The wildest performance increases were in people's crisis response (131% increase), strategic solutions (288% increase) and information usage (299% increase). And we're talking about comparing against regular office conditions, think how the really bad office conditions affect people. It's crazy that in some schools there has been reported CO2 levels of even 6000 ppm momentarily. No wonder I remember almost nothing from the history classes in school (probably not at all due to the sleep deprivation for staying up too late). Even crazier is that the regulatory limit for CO2 in indoor air is 5000 ppm average during an 8 hour time.
This may be over-exaggerating, but very interesting all-in-all. I think it definitely is important to measure indoor air quality accurately.
And what about the bigger picture? Just food for thought, if this is how carbon dioxide indeed affects us, what does the rising levels of carbon dioxide in the environment do to our performance and wellbeing as a society? The concentration of CO2 in nature has rose from around 280 ppm of 1950's to the 406 ppm of today and just continues to rise at an accelerating pace. And how about NASA's forecast of 1500 ppm CO2 concentration in the time of few centuries from now?