The Age of HVAIC

(H)eating, (V)entilation, and (A)rtificial (I)ntelligence (C)onditioning

I heard the sound for the first time in the kitchen, by the gas range, while making my morning eggs.

It was a light metallic clanging, almost a pleasant chime, except it wasn’t pleasant at all but quite concerning. The noise travelled up the gas line from the basement, where our twelve-year-old gas furnace struggled to warm up the house during the coldest winter in recent memory.

My wife and I live in northwestern New Jersey, in a very old house, dating back to the mid-1800s. It used to be the general store during the years of the Morris Canal, and keeping our humble adobe warm has always been a challenge, none more so than this past February when the polar vortex squatted over a significant chunk of the country.

I’m somewhat handy around the house, but when it comes to electricity or heat, I leave it to the professionals. I recorded a snippet of the noise on my smartphone and sent it over to them. It was received with a collective shrug. “I’ve been doing this for a couple of decades,” my HVAC guy said, “and I’ve never heard anything like that.”

He sent out one of his techs. In the basement, we both listened to the noise when it occurred the longest, a good twenty seconds, around 8am. I told him the noise stops when I open the panel. He said we should try replacing the gas valve, because there was a 90% chance it was the culprit.

It took him less than ten minutes to replace the valve and charge me $850. Expensive, but if it fixed the problem, worth it. Unfortunately for me and our furnace, the noise continued unabated. When I reported back to the tech’s boss, he said he’d have to come out the following week because he was so backed up with other work. Not what I wanted to hear. What disappointed me the most was how uninterested he was in thinking through this problem of ours. Probably because he had another dozen people like me, all with distinct issues of their own.

And that got me thinking. I knew of something that had all the time in the world for me, any time of the day: AI.

Being a certified geek, I went to work. I set up my laptop and a decent microphone (podcast quality!) by the furnace and recorded a whole day’s worth of sounds. Because I’m familiar with working with audio in its digital waveform, I was able to create a time-based report. I’d surmised the clanging would be most prolonged when the furnace came on early in the morning (we drop the house temperature from 69 to 58 degrees Fahrenheit), but that didn’t turn out to be the case. The inducer, the motor that controls the airflow inside the furnace, ran for 30 seconds when there were no clangs, but then ran for double that number with the clangs. I counted 23 clangs at its longest, around 8am, and as the day went on, the number dropped with each subsequent heat cycle until it disappeared altogether by 1pm.

I created a 57-second snippet of the clanging into an MP3 file and uploaded it and the report to Google’s Gemini, and here’s what it said:

Based on the audio recording and the detailed log of your furnace’s behavior, the rhythmic clanging you’re hearing is a classic symptom of condensate (water) backup or moisture in the pressure switch system.

The most telling clue is the “recovery” pattern in your log: the noise began immediately after a very long heating cycle (1 hour and 48 minutes) and gradually disappeared over several shorter cycles as the “clang” count dropped from 23 to 0.

After some more chatting, I realized I’d neglected to add what might be a crucial data point: The clanging stops immediately when I open the furnace’s top panel. What do you think?

Thus decreed Gemini:

This is a “smoking gun” in furnace troubleshooting. When a noise stops immediately upon removing a cabinet panel, it almost always points to an airflow restriction—specifically in the combustion air intake.

Bingo! I further informed my HVAIC of our concentric vent, where the intake is situated behind the exhaust. Because we have had consecutive subzero temperatures, the vapor cloud from the exhaust was most likely frosting the intake vent during the longest cycle, when the furnace ran for almost two hours straight. In layman’s terms, because it was so hard to breath out, the furnace was having trouble breathing in.

That very evening, I drove to Home Depot and bought a PVC pipe, a plastic ring adapter, and insulating foam for $10.92.

I didn’t need the foam so the fix could’ve been even cheaper. After extending the exhaust by 14 inches, the highest number of clangs reduced to three.

I relayed my triumph to the HVAC guy, hoping being bested by a large language model would guilt him to come back on his dime so he can further follow Gemini’s instructions. He did return, eventually, to do maintenance and also to comment that the exhaust vent now looked like a toilet plunger. He’s not wrong, but I love my plunger vent nonetheless.

Meanwhile, I thought of all those insufferable AI commercials during Super Bowl 60, and wondered if my HVAC guy saw them, too, thinking his line of work was safe from the oncoming AIpocalypse. I’m afraid these machines are coming for all of us.

p.s. For the curious, my very full conversation with Google Gemini: https://gemini.google.com/share/834b358a7a46