DB25 #15 — heating season

I grew up on the East Coast, where we had a regular progression of seasons. Starting at New Years and working around the calendar, we had cold, wet, spring, it’s not supposed to be this hot because it’s still spring, summer, school, it’s not supposed to be this hot because it’s fall, fall, it’s not supposed to be this cold because it’s still fall, holiday, and winter. You could usually tell which one it was by the color of the trees and the accompanying discussion of what the trees would soon look like.

Of course, the real reason we have seasons is so we can reflect on how much worse those poor souls living in the Bay Area have it. They, of course, run on some kind of bro-it-out rapid development cycle that lets them crush out all the seasons in the space of a day. Basically 996 of climate. Eventually, the west coast relented and added the two new seasons that we recognize nationwide. Pumpkin Spice Latte and Peppermint Mocha.

The homeowners among us might recognize also heating season. Costs about the same as holiday season, but it’s spread out over a few more months.

If you weren’t just a homeowner but a hotel owner, there’s no way that you would want a bunch of wassailers blowing into town and reveling the start of heating season on your dime. You’d need something like the Trane Tracer system. With that, you could centrally manage all the individual fan coil units in each hotel room through their Unit Control Module.

UCMs are strung together daisy chain with sensors for each zone but Trane says little about their protocol. Why would they? You connect the wires to a box called a Tracer, then connect a DB25 from that to a computer. The Trane Tracer control box is our 15th entry in the series. A little lame, since it's just ordinary RS-232 over DB-25. From what I can tell about the protocol, and from my own time tinkering with troublesome hotel fan coil units, the Tracer to UCM protocol was a packet-based RS-485 protocol that you could manipulate through a dial-up connection to a Tracer. It was not uncommon for the Tracer modem to be connected to the hotel PBX. Anyway, exciting times.

Why did Trane want to be in both the building control market and the air conditioning market? Who says they did? I think it's just as likely that they were in one to protect their position in the other. Which was which? I'm not sure they knew.

The start of heating season doesn't leave me a lot of time to ponder the motives of other heating firms, especially when the seasonal bring-up of my own overcomplicated and home-grown boiler system looms. Perhaps this is the year I will finally master the balance between the radiant floor, cast iron, and sheet metal radiator zones. Perhaps this is the year that the system will stay well-bled and not make waterfall noises in the night. Trane's protocol offers little to help with that issue.