Influence of mechanical ventilation system on indoor carbon dioxide and particulate matter concentration

Abstract

a b s t r a c tCommon ventilation strategies may fail to maintain indoor air quality when atmosphere is heavily polluted by particulate matter. This paper evaluates the performances of common constant air volume (CAV) system and variable air volume (VAV) system when carbon dioxide and particles are significantly present in outdoor environment. Major system parameters including filter efficiency, occupancy number, ventilation air rate, and outdoor particle concentration are thoroughly examined. Firstly, a full-scale chamber experiment is performed to investigate the dynamics of CO 2 and airborne particles under steady and non-steady scenarios. The result is further validated with a previously-developed state-space model. Secondly, an exhaustive case study is conducted using an established mathematical model. In order to reduce CO 2 concentration, both CAV and CO 2 -based demand-controlled VAV may cause an undesirable increase in particle concentration when outdoor air is heavily polluted by particles. This dilemma requires further studies on the optimization of ventilation schemes.

The impact of particle filtration on indoor air quality in a classroom near a highway

“…A limitation of our study is that we studied only one mechanical air filtration system with one type of filter in one classroom in one school. The impact of an air filtration system on classroom air quality varies with the building characteristics, occupancy, outdoor concentration, season, and ventilation conditions (Yu et al, 2014). We might have found different reduction percentages under other conditions.…”

Indoor air quality control for improving passenger health in subway platforms using an outdoor air quality dependent ventilation system

“…The process model from the manipulated variable (PM 10 amount introduced from the outdoors to platform) to the controlled variable (platform PM 10 concentration) is G p ðsÞ ¼ 0:22658 1 þ 0:0641s expð À 0:44796sÞ (8) where the process gain, which explains how much the controlled variable changes in response to the variation of manipulated variable, is positive (K ¼ 0.22658). This implies the PM 10 that enters the platform from the outdoors increases the PM 10 concentration inside the subway platform [14]. The disturbance models identified from the waiting room PM 10 variable and subway frequency variable, respectively, are G d1 ðsÞ ¼ 0:62838 1 þ 0:04726s (9) G d2 ðsÞ ¼ 0:41117 1 þ 0:0465s expð À 0:90sÞ…”

“…These researchers have assumed that the polluted indoor air is replaced with clean outdoor air by increasing the ventilation rate. In fact, if the outdoor air is strongly contaminated due to aeolian transportation of dust particles or yellow dust, its entry into the building spaces through the ventilation systems increases the air pollutants inside the building spaces [13,14]. This article proposes a new approach that considers the outdoor air quality used for diluting indoor air pollutants.…”

“…[15,16]). If the ventilation system is operated with the identical ventilation rate to the usual, then a larger amount of PMs enters the subway system through the ventilation under such contaminated outdoor air conditions [14,17]. The PMs with aerodynamic diameters less than 10 mm (PM 10 ) and 2.5 mm (PM 2.5 ) deposit to trachea-bronchial compartment of the human respiratory system, and then, cause respiratory illnesses such as bronchial asthma, rhinitis and chronic bronchitis [18,19].…”

Indoor Air Contaminant Adsorption By Palm Shell Activated Carbon Filter – A Proposed Study

“…The increasing concern towards indoor air quality (IAQ) have gained the suitable technique on mitigating the indoor air contaminant [2] which can effect on health and working performance [3]. Volatile Organic Compound (VOC), Carbon monoxide (CO), Carbon dioxide (CO 2 ), and particulate matter defined as the major contribution of indoor air contaminant.…”