For example, let’s look at the thermostat heat anticipator.

This nifty little device actually shuts off the furnace or air conditioner (or heat pump) before the desired temperature is actually reached.

It “anticipates” reaching the desired temperature and compensates accordingly. When a space is heating up, there’s a phenomenon called the “flywheel effect” where a space will continue to heat up for a short time even after no new heat is being introduced.

They also help desensitize the thermostat so that when it’s near the desired room temperature, it doesn’t continually turn the furnace or a/c on and off which can damage your equipment.

Newer programmable thermostats actually have learning algorithms built into them to figure out how to do this optimally (part of the reason why they can save you money), but they’re present in virtually all thermostats and the actual mechanics are pretty simple and certainly don’t require an electrical engineering degree to understand.

The heat anticipator is an electrical resistor that includes a tiny heating coil and a temperature sensing bimetallic spring.