David Schamus
Said, “A whole house low voltage system … could easily reduce the amount of 120/240 wiring in a home and reduce fire risk…”
Tradeoffs are the major problem. The cost of half inch diameter copper wire to wire a home with 12V would be prohibitively expensive; and 5V would be 2.5 times more prohibitively expensive. It would greatly increase the amount of copper in the house wiring.
Fire risk still depends on the power to the outlet. If the outlet needed 120 watts = 120V at 1 amp or 12V at 10 amps, an arc fault would still dissipate the same amount of power.
But the amount of copper needed is the real problem. In other parts of the world with 230 or 240VAC, the wiring can be thinner while carrying the same power.