India being a developing nation, there is significant
improvement in road infrastructure across the country as well as
the spending power and earnings of the common man. This leads to
the new trend of customers become health and comfort conscious and
willing to pay more for better and improved transportation. To
satisfy these demands, OEM's are developing more numbers of AC
buses. Although the OEM's are meeting this demand of quantity,
the quality of air from air conditioner is still subpar. One of the
main reasons for this poor air quality is because of the
ineffectiveness of conventional air conditioner air filters to
control particulate materials i.e. PM2.5, biological pollutants i.e
microbes, bacteria, viruses, and gaseous pollutants i.e. CO, CO2,
SO2, NOX, O3 & VOCs in air. As per various researches, health
problems associated with bus occupant compartment air quality
appear more frequently. In this paper, research is shown on bus air
quality improvement with respect to conventional filters for
improving human health. Many people spend daily 2-6 hours of time
in travel through staff AC busses, about 9-10 hours in intercity
buses and 1-2 hours in city buses, especially in urban areas. It is
indoor pollutants that lead to poor inside air quality in busses,
sources of indoor particle pollutants can be plastic surfaces omits
VOCs due to higher temperatures inside vehicle, when vehicle soaked
in parking in summer and pollutant environment of most of the
cities. Conventional filters of busses are not capable of restrain
the pollutants, hence all occupants health are prone to have health
issues, which also impacts working efficiency of occupants. Indoor
air quality is the most important and comparatively overlooked
parameters considered by OEMs in air conditioner design. To solve
this concern of indoor air quality, VECV had evaluated comparative
performance of conventional and carbon activated filters in air
conditioner buses in controlled environment; as well as in actual
customer vehicles in Delhi NCRs, post festival of Diwali when
outside air quality was in worst out of year. With this new design,
carbon activated air filters were analyzed through CFD, for
reduction in air flow due to increased pressure drop and
corroborated with the physical trial of a vehicle with this new
design. The results of the average air velocity variation from
controlled louvers found 0.6-0.7 m\s lesser than existing design
& filtration efficiency of carbon activated filters found
better than conventional filters for PM level 10-12.5%, HCHO 97.4%,
VOC 97 - 99% respectively. VECV had also taken subjective and
objective testing of this new design filters in few of the buses
sold to customer. The feedback from the customers, received by
VECV, was overwhelmingly positive and was encouraging.