Data transfer over steel/copper tubing.

[BlackMamba]

Assume that one would want to transfer data using existing home heating installation. The idea is to use the heating installation to transfer some sensor data.

The bandwidth should be at least 2400 baud. Required range is below 100m, you know an average family home.

Is there any off the shelf tech that could be utilized for this kind of application?

 

[Harald Kapp]

Probably not.
To transfer information you need 2 wires. One for the data and one for ground (common return). The plumbing provides only one wire. You might argue that you could use earth as return path, but unfortunately the plumbing is usually grounded, eliminating this possibility.

For the range and data rate envisioned, a wireless solution could be employed, e.g. using ZigBee or a similar technology.

A crazy afterthought: you could use the plumbing to transmit data acoustically. If you knock on a heater, you can often her the sound in other rooms, too. Since you don't want to hear your sensors sending data, you would either have to employ infrasound (unsuitable due to low data rate) or ultrasound. I don't know how well ultrasound is transmitted via the pipes.

 

[BlackMamba]

Indeed it seems that ultrasound is the way to go [1][2]. However there seems to be no currently available applications of this technology.

[1]: http://dflwww.ece.drexel.edu/archives/3/1/Primerano_Richard_(1).pdf
[2]: https://umes.edu/cms300uploadedFiles/SPIE2011_timereversal_I.pdf

 

[Solidus]

Indeed it seems that ultrasound is the way to go [1][2]. However there seems to be no currently available applications of this technology.

[1]: http://dflwww.ece.drexel.edu/archives/3/1/Primerano_Richard_(1).pdf
[2]: https://umes.edu/cms300uploadedFiles/SPIE2011_timereversal_I.pdf

Many mid- to high-end tweeters (high-frequency sound drivers) can reproduce frequencies into low ultrasound ( ~30-35kHz, some up to and slightly over 40kHz). If high-passed around 25-26kHz (around the upper limit of hearing), they can form an ultrasonic transducer.

The only problem is that if you have any pets (particularly dogs), you will be forming a 2,400 bd. UART dog whistle.