Fireplaces are shockingly inefficient, which, as far as Cameron Scott understands it, means that you're basking in a mere 10 percent of the heat generated. The rest goes up the chimney. And burning wood creates substantial particulate pollution, which is why fires are banned on Spare the Air days. Must you, then, give up the exquisite pleasure of a fire? No; thankfully, there's the fireplace insert. More