## 1 Introduction  
The increasing population and high energy demand have led to energy crises and environmental problems in our world. To overcome these problems, countries are trying to switch from traditional internal combustion engines (ICEs) to electric vehicles (EVs). Although electric vehicles were proposed in the early years of the 19 th century and the beginning of the 20 th century, limited range and battery costs were disadvantages of EVs against ICEs. Restrictions of exhaust emissions of ICEs in the EU and political pressures increased research and development studies of EVs in the 1990s [1]. EV sales in the world market reached 6.61 million in 2021, and 10.25 million in 2022, and it is projected that they will reach up to 17.07 million by 2028 [2]. Although EVs are environmentally friendly and have lower running costs, range, battery storage capacity, charging-discharging characteristics, and battery life are the main drawbacks of EVs. Some research reported the predicted range of EV batteries [3]. The range calculations of EVs are performed by using the driving conditions, speed, acceleration, and the state of charge of the battery [4, 5]. These mentioned disadvantages are closely related to the electric vehicles thermal management system (EVTMS) [6]. Thermal management of air conditioning (AC) systems, batteries, power train systems, and other auxiliary equipment such as lighting affects driving range, life of components, and efficiency [7, 8]. Among the energy-consuming systems of EVs, the HVAC system consumes almost 33% of the total required energy to drive EVs [9]. Annual average HVAC energy consumption in a light-duty EV in all US states for a 19,312 km hypothetical ride shows that AC energy consumption is greater than the heating process [10]. Preconditioning of the vehicle cabin also influences the EV range [11]. A dynamic and modular AC system in an electric bus showed that fans and blowers consume up to 40% total energy in the vehicle [12]. EVs' driving ranges also differ with geographical and environmental conditions. The thermal comfort of the driver and passengers is important for pleasant and safer travel. Therefore, thermal comfort studies have always been a concern of HVAC designers [12; 13]. To ensure thermal comfort, the HVAC system is a must in electric vehicles, as in all vehicles. There are several theoretical, numerical, and experimental research works published in the current literature concerning HVAC systems in EVs [6; 9]. Some of the related works and their findings are mentioned here. Simulated models in MATLAB for range estimation of EVs concerning energy consumption of battery due to traction and HVAC revealed that measurements and simulations results are close to each other (less than 2.59%) and can help to overcome range anxiety of drivers [14]. A dynamic program was proposed to solve the battery management dilemma between energy consumption and thermal comfort. Variations of traction energy, AC energy, surplus energy, and thermal discomfort with travel time were presented [15]. Cabin heating of EVs in cold climates is energy intensive. A cabin heating and powertrain optimization platform was created and tested for a plug-in EV, and results showed that the proposed system can increase EV energy saving up to 26% [16]. Four model-based controller approaches including feedback controllers, a decentralized-proportional integral controller, and a centralized linear-quadratic-integral control strategy were designed and compared for AC systems in EVs [17]. Comfort parameters in an EV cabin such as air temperature, relative humidity, and volatile organic compounds (VOC) were measured for different HVAC modes. Energy consumption values of these different modes were compared [18]. A reversible heat pump HVAC system was designed with a regenerative heat exchanger for EVs.