Cooling down - [engineering HVAC]

This article looks at the state of air conditioning engineering at hot summer in the United States. No longer the mammoth machines of yore, today's models are sleeker, more cost- and energy-efficient, and manufactured by companies that have mandates for controlling greenhouse gas emissions. In the summer, this is particularly perplexing for air conditioning engineers. Yet, carbon emissions are an entirely different matter from increasing the air conditioner's efficiency.