[Head416]

My brother in law installs these ^ systems. For the fire marshal test they walk into the room, discharge the system, and try to light matches. The matches don't burn, system passes.

It lowers the oxygen percentage enough that the fire can't burn, but it's not dangerous like halon (which isn't used anymore).

He does do some residential stuff, but it's more like a system for a datacenter or studio within a home, not the whole home. The systems are designed for a finite confined space. I guess you could make that space your whole house but since houses aren't really sealed between rooms it would have to displace oxygen in the entire house at once if there was a fire anywhere. An open door or window would make it ineffective. The system couldn't protect from a fire on the exterior of the house (catching from a tree or neighbor's house).

So you'd have an expensive system with limited effectiveness, but yes it could be done.