As the heat continues to blister during this summer in New York, I think back to the first time I ever bought an air conditioner: fresh out of college. It was a daunting investment, but well worth the quality-of-life improvement. I stumbled through a few consumer report roundups online, asked the advice of friends and coworkers, and eventually found myself at a local hardware store, where the owner enlightened me to the complex world of BTUs, replaceable filters, and square footage calculations. Within 30 minutes I had a giant box on a dolly and 300 more points on my recently opened credit card.