Due to the rise in global temperature and climate change, the detection of CO2, SO2 and
NO pollutants is important in smart cities. In this paper, an H-shaped photoacoustic cell is utilized for
the detection of low-concentration gases. The geometry of the cell is miniaturized and designed with
specific parameters in order to increase its efficiency and performance. The designed cell eliminates
problems such as bulkiness and cost, which prevent the use of sensors in detecting greenhouse
gases. The simplicity of the design expands the application rate of the cell in practice. In order to
consider the viscosity and thermal effects, the cell is formulized by fully linearized Navier–Stokes
equations, and various parameters, such as acoustic pressure, frequency response, sound speed
(sound velocity) and quality factor, are investigated for the mentioned gases. The performance of the
system is frequency-based, and the target gases can be detected by using a microelectromechanical
resonator as a pressure sensor. Quality factor analysis expresses that CO2, SO2 and NO gases have
quality factors of 27.84, 33.62 and 33.32, respectively. The performance of the cell in the resonance
state can be expressed by the linear correlation between the results. The background noise generated
in the photoacoustic research has been removed by miniaturization due to the obtained resonance,
and the proposed cell provides a proper signal-to-noise ratio. The results of the proposed system
represent the increase in the quality factor, which reduces the losses and thus increases the sensitivity
of the system in the study of greenhouse gases.