The first law of Thermodynamics teaches us that energy cannot be created or destroyed. While this is true, it can be wasted. I am thinking specifically of the energy used to condition (heat or cool) a room. Everyone thinks, “Heat rises.” While heat can rise, it doesn’t have to. Heat is lazy. It is going to slowly move from its greatest concentration to the least concentration; the path of least resistance. When it is hotter outside than it is inside, that heat is going to enter your building the same way—as effortlessly as possible. You want to spend less to condition your space? Air sealing is key. It is as important as insulation and often over looked. Blower door testing can help you do this. However, you can do a “cheap and dirty” test is to just walk the space. If you can feel a draft, it is more than likely caused by that lazy, lazy heat moving through the space.