Heating & Cooling

Heating and cooling is the biggest line on most US energy bills, usually around half of it. This section covers the changes that actually move that number: insulation and air sealing first, then thermostats, heat pumps, furnaces and AC, and what each one costs to buy and run. Every guide shows the upfront price, the yearly saving and how long until it pays for itself, along with the federal and state rebates that apply.