Search Results

Climate change is a global issue affecting every industry. Automotive companies have been working to address this issue by reducing the greenhouse gas emissions of their vehicles. EPA has encouraged this by providing incentives in the Greenhouse Gas Emissions Rule of 2009. Improving the efficiency of MACs (mobile air conditioning systems) is part of this effort. Life-cycle climate performance (LCCP) is a comprehensive metric for estimating the greenhouse gases emissions produced by the construction, operation, and end-of-life recycling of a vehicle MAC (Mobile Air Conditioning) system. Many companies and organizations have conducted LCCP for their vehicles using various software tools.

The EPA has issued regulations in the Final Rulemaking for 2017-2025 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards (420r12901-3). This document provides credits against the fuel economy regulations for various Air Conditioning technologies. One of these credits is associated with increased use of recirculation air mode, when the ambient is over 24°C (75°F.). The authors want to communicate the experiences in their careers that highlighted issues with air quality in the interior of the vehicle cabin. Cabin contamination sources may result in safety and health issues for both younger and older drivers. Alertness concerns may hinder their ability to operate a vehicle safely.

The United States Environmental Protection Agency (EPA) as well as the European Commission (EC) are developing test procedures to regulate mobile air conditioning system (MAC) efficiency to reduce greenhouse gas emissions and reduce global warming. In the United States, air conditioning related MAC credits can be earned by implementing an internal heat exchanger (IHX) into a MAC system. By integrating an IHX into a MAC system the, Coefficient of Performance (COP) can be increased at the same time increasing cooling capacity. This improvement in efficiency reduces the energy and/or fuel consumption of the MAC system. This paper will compare various IHX plumbing configurations for a dual evaporator system with R1234yf refrigerant. A MAC system optimized for efficiency as well as evaporator cooling capacity is used to assess these different IHX plumbing configurations.