So the HVAC guys were just here for a second day, and the new furnace (a Carrier Infinity 96) is almost installed (almost). It’s bigger, noisier (well, sometimes) than the old one, but here’s the deal: It works.

It’s also smarter than the old furnace (which, after all, was a whole 27 years old). We no longer call its thermostat a thermostat; it’s a controller. The controller talks to the AC and furnace, like a thermostat does, but these days the AC and furnace also talk back to the controller and some of the information they deliver is pretty deep.

The controller adjusts operation according to the humidity, airflow, temperature outside at the AC compressor, all sorts of things. It checks to see if the furnace filter is dirty and tells you to change it if it is. It’s got a manual as long as FreddieMac’s, too.

The controller regulates furnace speed automatically, mostly keeping it on energy-saving low, but in high mode it bears a striking resemblance to a Cessna Citation revving up to take off. (The installers say they’re coming back to fix that, and to enlarge some of the ductwork).

For now, the loudness reminds me that we’re no longer freezing in here. Yippeee.