Carbon Dioxide Human Gains—A New Approach of the Estimation

Abstract

Human health is dependent on the Indoor Air Quality (IAQ) of residential and public buildings, where people spend a substantial amount of time. Part of IAQ parameters, like temperature or humidity influence the thermal comfort of users, whereas too high carbon dioxide concentration (CO 2 ) could cause various complaints or diseases. In buildings like offices and schools, where we have a brush with a high density of users, the main source of CO 2 is simply people. The type of their activity brings higher or lower carbon dioxide gains, that must be taken into account to design and properly use room ventilation, allowing recommended CO 2 levels not to be exceeded. This paper presents an approach to marking human CO 2 generation off by using an experimental method. The method was verified based on measuring results of six test series conducted in different types of rooms at Bialystok University of Technology (Poland) during lectures, meetings, projects and laboratories. Carbon dioxide gains were comparable with an average value of 0.0045 L/s, which corresponds to theoretical CO 2 generation rates that are symptomatic of males and females, between 16 and 30 years old, with low physical activity.Sustainability 2019, 11, 7128 2 of 12 dioxide concentration, is not considered particularly dangerous as such its high level could result in a room occupants becoming drowsy, fatigued and with insufficient ability to concentrate. A review of the literature conducted by Johnsona et al., [8] showed that there was an association between low-level exposure to CO 2 beginning at 700 ppm and building-related symptoms, whereas respiratory symptoms were indicated in children in a case of indoor CO 2 concentrations higher than 1000 ppm. However it was not possible to eliminate other causes of health problems. As highlighted by Meciarova et al., [9], CO 2 is not considered a pollutant of concern, but as an indicator of how well other people-related pollutants are controlled-particularly odor-causing compounds. As underlined by Lu et al., [6], the concentration of CO 2 in office buildings is primarily dependent on occupant density and ventilation rates. It is worth noting that CO 2 concentration is often found above recommendations in buildings with high people density and insufficient ventilation, especially schools [10][11][12][13][14][15][16][17]. Problems with CO 2 concentration in residential buildings were discussed by Mainka et al., [18].Nowadays, the ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers) standard [19] recommends indoor CO 2 concentrations less than 700 ppm above the outdoor concentration, giving also a guideline of 1000 ppm. Thus, the CO 2 recommended level is significantly lower than several years ago. As analyzed by Persily et al., [20] in 1981 the CO 2 limit of 4500 mg/m 3 (2500 ppm) was proposed in an appendix, while in 1989 the value was decreased by 60% to 1800 mg/m 3 (1000 ppm) and such a level was maintained in the 1999 and 2001 versions of the Standard 62.Sufficiently high venti...

Tent versus Mask-On Acute Effects during Repeated-Sprint Training in Normobaric Hypoxia and Normoxia

“…Currently, the recommended level of CO 2 is <3000 ppm when exercising [ 15 ]. Outdoor CO 2 concentration is 350 ppm, and the indoor level is usually 700 ppm above outside levels, reaching 2800 ppm and provoking no severe symptoms [ 31 ]. The combined chronic effect of hypoxia and high CO 2 during exercise must be explored in the future, based on recent evidence suggesting some issues when exposed to hypercapnic and hypoxic environments [ 32 ].…”

“…Considering these results, athletes, coaches, medical staff, and other stakeholders should address the differences between performing RST using a tent and using a mask when simulating hypoxia. It should be known that repeated-sprint workouts represent a challenge to the body that is exacerbated under hypoxic conditions and could be boosted by other environmental factors such as high CO 2 levels and the rise in WGBT [ 31 , 39 ]. Some studies have suggested that combined hypoxic and heat stress should be explored more in-depth [ 40 , 41 ] Despite the steady increase in WGBT inside the tent, the isolated and controlled conditions of this study did not allow the WGBT to rise to hazardous temperatures.…”

Dynamic ventilation certificate for smart universities using artificial intelligence techniques

“…Most of them take into account the amount of CO 2 generated by a person. A person's CO 2 emission has in fact been defined in different studies [22] , [23] , [24] , [25] . A healthy person, on a normal diet, generates an amount of CO 2 that can be expressed as ( eq.…”

“…Other results, such as those obtained in [25] , show that these values may differ according to the region. In addition, [22] presents experiments under different conditions with the aim of obtaining a measurement of the amount of CO 2 based on experimental measurements.…”

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“…This reflects the fact that in a real scenario the infiltration may have small deviations from the true value [36]. Similarly, the CO 2 generation per occupant in the room, c CO 2 occ , in any case cannot be a crisp value, since it strongly depends on factors, such as the type of work that an occupant performs during its presence in the room, the age of the occupant, the gender of the occupant, and various physical characteristics [37,38]: a young child's carbon dioxide generation differs from an adult heavy worker's.…”