How do you interpret,,,

Unknown

direct-flame heat energy transfer,, to radiant energy (unseen) transfer,,,,



I have my ideas,,, but what do you people say?

TonyS

I suppose

the sun would be one. Or the overhead gas fired radiant heaters they use in hangers. Or the small gas fired ceramic infrared space heaters. These things burn fuel but transfer their heat by radiant waves???

ErikV

As I understand it ...

.. heat only moves 3 ways: conduction (touching), convection, radiation (radiant waves across an empty space).



And convection is really a special case of conduction (energy transfer between touching substances due to atomic vibration or electron transfer), because in convection a fluid flows over another substance, enhancing conduction between them.



Sounds to me like:

- direct flame energy transfer is what happens in the boiler, when those flames lick the coils. This would be mostly conduction (direct heat transfer from the flame/air to the coil), with some convection (hot air forced to move in the boiler chamber).



- radiant energy transfer is what happens at the heating appliance in the living space (this is only radiation, from radiators, RFH plates, etc., no conduction). Once the radiant transfer is done you get some conduction and convection, when the warm air goes on to heat you and me. Or if you are lucky, you're next to that radiator getting radiant heat directly.