Watch: down in the mechanical room
Sound's on — this is me heading down to the mechanical room and working out what I'm looking at. Music's just underneath; the voice is the real thing.
Watch on YouTubePart 2 — down in the mechanical room
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The call was about the roof
If you read Part 1, you know this started as a rooftop job — a 30-ton gas/electric package unit up top at a church in East Baltimore that began life as a 1910s movie theater (the old Princess Theater) before the congregation took it over in 1933. (Maryland Inventory of Historic Properties B-3970.) That was the reason for the visit. But then I went down into the mechanical room, and the story changed.
That theater past matters down here too. A building that's been a movie house, then a church, then added onto for the better part of a century collects mechanical systems in layers — each generation bolting its own equipment onto whatever the last one left behind. The basement is where you read those layers.
Half of a system, hiding in the basement mechanical room
Down in the basement is a 180,000 BTU air handler — and this one I can read: it's a York. That's the indoor half of a split system: the air handler lives inside, the condenser lives outside, refrigerant lines run between them. Completely separate from the rooftop package unit. The roof handles part of the building; this split handles another part. So what's down in the mechanical room is only half of it — the other half is out back.
For scale: 180,000 BTU is 15 tons of capacity sitting in the basement. That's a serious chunk of conditioning that has nothing to do with the unit they called me about.
The detail that dates it: R-22
Here's the one that matters most. This system is running on R-22 — the old refrigerant.
R-22 was phased out by the EPA: as of January 1, 2020, it can no longer be produced or imported in the United States. You can't buy new R-22. The only supply left is reclaimed and stockpiled, and the price climbs as it dries up. So the day this system springs a real leak, you're not topping it off cheap — you're looking at expensive reclaimed gas or a conversation about replacing the whole thing.
R-22 isn't a problem until it leaks. Then it's the whole ballgame.
That's the kind of thing a building owner needs to know before it fails on the hottest Sunday of the summer. Finding it now, on a calm walkthrough, is the whole point of actually going down to look.
The condenser out back
Outside, there's a condenser, caged and fenced in — protected, which tells you somebody cared about copper theft or vandalism at some point. I could read it clearly: another York. That's the outdoor half of the split — the piece that pairs with the air handler downstairs. (The old furnace venting and electrical guts? That story lives with the rooftop package unit over in Part 1 — it's not part of this basement split.)
So between the rooftop and the basement, this one building is running at least two completely separate systems, on at least two different vintages, with one of them on a refrigerant you can't buy anymore.
Why this is the real job
The lesson here is simple and it's worth saying plainly: the call was the roof, but the additional risk was in the basement. If you only ever look at the thing the customer points you to, you miss the 15-ton R-22 split that's one leak away from a bad day.
Walking the whole building — roof, basement, out back — is how you give an owner the real picture instead of a quote for one box. That's the difference between selling a part and actually knowing the building.
← Read Part 1: The 30-Ton Rooftop Nobody Could Read
Sources & honest notes: The building's Princess Theater origin is from the Maryland Inventory of Historic Properties (B-3970); R-22 phaseout dates and production/import ban from the U.S. EPA; tonnage-to-BTU conversion is standard (1 ton = 12,000 BTU/hr per the U.S. Department of Energy). I've kept this to what the footage actually supports: the air handler reads 180,000 BTU and York and the system is on R-22; the backyard condenser also reads York. Where I couldn't read a nameplate, I didn't put a brand on it.
About the author: Gregory Frazier is a heavy commercial HVAC estimator working Maryland, Pennsylvania, Delaware, Virginia and Florida for 25+ years. Read his story →