No clue.. yet, until I get a glimpse of the units. So far I only have a=20 basic description from the last A/C who was here some months ago. On 6/1/2017 6:15 PM, Clint Jay wrote: > Can you get to the pipework more easily? Might be possible to clip > something to that instead ? > > On 1 Jun 2017 11:13 pm, "Neil" wrote: > >> Hi all, >> >> My neighbor and I are trying to find the source of a noise that's >> bugging us, which is from one of 6 A/C units on the roof above us. It's >> a periodic hum, plus a noticeable rattle when the thermostat switches >> off that unit. I've asked the A/C service guy to check and he says it >> would take quite some time to monitor for that. >> >> I know it's not my A/C unit as the hum/rattle does not coincide with the >> operation of my A/C. Same for my neighbor. One of the other possible >> residents is gone for 11+ months each year, and I doubt he'd leave that >> unit on all year. So that leaves 3 units. Coordinating with the other >> residents has been difficult, so I'm thinking I can come up with some >> sensing device that can remotely alert me as to which unit is switching >> on/off at any time. The other complication is that I am not allowed to >> be on the roof (insured A/C repair persons only), but I can just >> probably just deploy the sensor with a drone perhaps. >> >> So... what's an easy way to sense this? Getting a current sensor around >> the A/C lines will be difficult, but a vibration sensor magnetically >> attached to the side of the unit should be simple. I'd think I can >> create a small circuit with an accelerometer and a processor (perhaps an >> Arduino), then add some type of wireless transmitter, and a power >> source. BTW, power really only needs to last a few days. And then >> there's enclosing/waterproofing. >> >> Alternately, I'm wondering if I can mount a wireless camera up there >> facing all 6 units and vertically attach a stick to the side of each >> unit and see which one rattles when the A/C goes off. Assuming the >> rattle is enough to visually move the stick. I'm fine with low-tech. >> Any other ideas. >> >> I really don't have a lot of time for custom circuitry right now. There >> has to be a simpler way. Is there some pre-made device I can use to do >> this, or most of this? >> >> Cheers, >> -Neil. >> >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .