ZAFJB

ZAFJB t1_j29pvy9 wrote

> The same thing happens to heat a gas car, it's just using waste heat from the engine.

Most cars do not use exhaust heat to heat the cabin. They use a water to air heat exchanger that extracts heat from the water cooling system. So, combustion heats water >> water heats air.

2

ZAFJB t1_j29p2l9 wrote

The combustion changer takes in air from, and exhausts fumes to, outside of the room.

A heat exchanger transfers the combustion heat to the room air.

The heat exchanger circuit is hermetically isolated from the combustion chamber.

       ╔═══════════════════════════════════════════╗
       ║                                           ║
       ║                 Room                      ║
       ║                                           ║
       ║     ┌───────────────┐                     ║
───────╨─────┘ ┌───────────┐ │                     ║
> Air in       │           └─┴────────────         ║
───────╥─────┐ │           Hot room air out >      ║
       ║     │ │           ┌─┬────────────         ║
       ║     │ │           │ │                     ║
       ║     │ │           │ │                     ║
       ║     │ │           └─┴────────────         ║
       ║     │ │           Cold room air in <      ║
───────╨─────┘ │           ┌─┬────────────         ║
< Exhaust out  │   Heat    │ │                     ║
───────╥─────┐ │ exchanger │ │                     ║
       ║     │ └───────────┘ │                     ║
       ║     │   Combustion  │                     ║
       ║     │     chamber   │                     ║
       ║     └───────────────┘                     ║
       ║                                           ║
       ║                                           ║
       ╚═══════════════════════════════════════════╝
3