Welcome to my 'green' instructable! I am going to show you how to use an Arduino, two servo motors a temperature sensor and some metal (or wood) to make a digital thermostat for a through-wall HVAC unit. According to CB Richard Ellis (a major real estate firm), New York City is a renters market, with only about 1/3 of the population owning their home (versus almost 70% home ownership for the rest of the US) ...