It's important that we test all electric heaters in the same way. We measure how hot they get (or the heat output from a fan heater). We measure how fast the air moves out of each heater, which is especially important for fan heaters, where they're designed to push air into the room. We also measure the temperature of our test lab, seeing the effect that each heater has. We measure electricity consumption on the highest and lowest settings, so we can gauge how much each product will cost to run. Finally, we test any smart features and apps that a heater may have.