Arduino Furnace/Home Thermostat

Arduino Based Furnace/Climate Control Thermostat. The project will use an Arduino Mega 2560 and ITDB02 3.2" TFT to provide a climate control thermostat for a furnace with some data logging and/or display abilities to keep track of how long the furnace is running and a "graph" of temperature and humidity trend. Additionally it would require a temperature and humidity sensor. This will control a basic, electric home furnace to provide heat, cool and humidity control. It should have a heat, cool and auto setting as well as a setting for humidity that would control a simple whole home humidifier that's normally attached to a furnace. Should the humidity rise above a specified level the Arduino would activate a dehumidifying cycle which would start the cooling cycle while intermittently activating the heating coils to prevent a drop in temperature and keep the cooling coils from freezing. The auto setting would maintain a steady temperature by cooling the room if it gets too hot, and heating the room if it gets too cold. If I'm not mistaken a system like this would use a 7 wire thermostat, so this project would be using an Arduino to act as a 7 wire thermostat and provide some extra features that a basic thermostat doesn't.