Characterizing the marginal basis source energy and emissions associated with comfort cooling systems

A ten-story commercial office building located in Fort Worth, Texas, was used as a prototype to investigate the environmental impact associated with applying various electric and gas technologies for providing ventilation and comfort conditioning. The instantaneous (hourly) electrical and gas requirements demanded by the building were ``traced`` back to their source, the point where fuel is extracted from the ground The total energy consumed and emissions produced are quantified for both electric and gas technologies. On an annual basis, electric technologies had carbon dioxide emissions that were 20% to 26% lower when compared with the gas cooling technology. The gas cooling technology had lower total carbon monoxide emissions; however, after accounting for environmental oxidation of the carbon monoxide emissions, the gas cooling technology had an overall 24% to 35% greater oxide of carbon emission impact. The gas technology had a 19% to 25% lower oxide of nitrogen emission rate when compared with the electric technologies. The gas technology had a 3% to 15% lower annual total emission of sulfur dioxide compared to electric technologies. The primary reason for this is the absence of sulfur in the ``clean`` fuel assumed to be used by the gas technology (natural gas). The gasmore » cooling technologies required 20% to 30% more energy to be extracted from the earth to provide the equivalent space conditioning for the prototypical office building when compared with the worst-and best-case electric technologies, respectively.« less