Wednesday, July 23, 2014

Relay Computing, Redux

On Saturday, November 26, 2011, I posted about my nearly-twenty-year-old furnace and its relay computer control systems, and installing An AprilAire humidifier. Two days ago, instead of cool air, to combat the ghastly late July heat, we were treated to the smell of burning insulation. At first, we assumed it was my jumkbox PC (see Separating Work from Play, along with Update 1 and Update 2). I'm loading its very cheap Chinese power supply fairly heavily and it has been very warm. Alas, sniffing the heating duct proved this not to be the case.

Diagnosis: the fan motor had burned out. Our technicians who serviced the thing had been saying, virtually unanimously, "It's working ok now, but it's (19,20,22) years old, and it's not worth spending a dime on parts for it." We took their advice.

So new furnace, one of these Lennox modulating furnaces. Instead of waiting for the house to drop to a low enough temperature to make firing up the big guns worthwhile, it has a range of low power settings down to 35 percent, and will use them when the house is only a degree or two low. It's rated at 97.5 efficient. We also got one of these air conditioners with it. It's a midrange model (whereas the furnace is top of the line) since we cool sporadically 3-4 months a year and heat continuously nearly 8, and the furnace's uber-blower serves both systems.

Expensive? Yes. Does it come with a lot of cool bells and whistles? Yes. The control system on this furnace is impressive. It can control the humidifier. It has an outdoor temperature sensor built into the air conditioning unit. It runs diagnostics on itself It has, I'm told, a Carbon Monoxide sensor built in. It has a directly connected air intake. Its exhaust flue is PVC and plumbed out through the side of the house. The system is nearly silent. It can download its own firmware. Did I have surge suppressors put in on both the AC unit and the furnace? You betcha.

It's not quite to the point of saying "Hal, turn up the air conditioner, please." But it's close.

Naturally the weather broke just as they started testing the air conditioner. Now it's lovely and temperate, after a small rain storm. We have the windows open, and we're enjoying the fresh air. And the amazing, impressive, digitally controlled HVAC system that looks as though they've installed warp drive in our basement... is turned off.

Go figure.


Wednesday, July 16, 2014

The Power of Denial

I've been doing some Raspberry Pi tinkering of late, messing with my desktop pi's configuration and what's plugged into what. As it turns out, this is the key to the mystery that's been bugging me these last couple weeks. I've been hearing music. Just little snippets, always of classical music. And this without my headphones on. So naturally, I'd check the headphones to see if my desktop mac's playing music from some website I didn't realize was so equipped. Nothing. Check the iPhone. On one occasion, it was the source, but that was music I recognized instantly as being part of my music collection. The little snippets of classical music persisted. I was to the point of thinking that, if one had to have auditory hallucinations, snippets of classical weren't unpleasant, or that someone working outside's music was being caught by the wind. For the most recent one, I glanced back at my Raspberry Pi. It couldn't be making sound. I'd unplugged it from my headphone amp. Could it? I took a closer look. That's when I noticed that I'd left one of my experiments plugged in. I had a set of earbuds plugged into the Pi. Sure enough, when I stuck one of the earbuds in my ear, I got classical music. I have MPD on my Pi. Like any good unix daemon, MPD starts at boot time and resumes whatever it was doing when it was stopped. Including playing music. I had MPD set up to stream from WCPE, a public radio station in North Carolina (Colorado Public Radio's streams are dreadful) specializing in ... you guessed it. Classical music. I was sure none of my computers were making music. I knew it wasn't coming through my headphone amp, because I'd checked. I knew my phone wasn't doing it, because I checked. I was sure it couldn't be any of my equipment, and I was about ready to call my doctor. Beware denial. "It couldn't possibly..." has a habit of becoming "verily, it could." Epilogue: I plugged the Pi back into my headphone amp, and I'm getting the music in my Sennheiser headphones now, in all its glory instead of little tinny snippets from an unknown source. Much better. -JRS

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