Start your car on a cold morning and walk around to the tailpipe. See that water dripping? That’s the way a high-efficiency, condensing boiler works. It removes so much of the heat from the flue gases that the gases turn to liquid and drip out. That liquid is acidic so we use neutralizes to deal with it before we dump it down the drain. Your car isn’t a condensing boiler, so it has a thermostat to keep the heater from heating the inside of your car until the engine comes up to a certain temperature. That’s to keep the acid out of your car’s muffler and tailpipe (Hey, repairs are expensive!). The next time your kids are yelling that they’re cold, and for you to turn on the heat, explain how a car is like a high-efficiency, condensing boiler. They’ll love you for that.