I'm working in a house that has a heating system I'm not familiar with.  It's a hydronic system with fin-tub heaters placed about 3 inches from the ceiling along the top of the wall.  The heaters are covered with 3/4 inch oak boards, a bottom piece and a front piece nailed together that stand about an inch from the wall and an inch from the ceiling.  The homeowner considers this a radiant heating system but my understanding of radiant heat would say that covering these pipes with 3/4 inch oak will block most if not all radiant heat and this is a convection heating system.  If I'm correct why would anyone put a convective heater on a ceiling and if I'm wrong, what exactly is getting warm enough to generate infra-red radiation and make these radiant?

Any insight would be greatly appreciated.  If I've posted this question in the wrong forum I appologize.

You are exactly right.

Fin-tube is not radiation as most of the energy emitted is by convection (the moving of air by temperature differential).

Fin-Tube is marginal - in terms of comfort - when installed correctly (at the perimeter and within an inch or two from the floor). If the hot fin (typically 180 AWT) meets the coldest air found below windows and at the outside wall the temperature differential will transfer the most heat into the room, bathing the cold exterior wall with warm air. Since the tube is at the ceiling (where most of the heat ends up with forced air or fin-tube "radiation") the temperature differential is lower along with the output.

Fin-tube is nearly useless when elevated, installed below floors and other creative but silly misapplications. But they did eliminate that annoying furniture against the wall thing. Steel wall panels do a better job and are real radiators.

OK it is quieter than forced air but still. But hey, it is cheap!

I like fin-tube best when it is on my scrap pile.

Even when installed as baseboard, the difference between fin-tube convector & cast-iron baseboard is like night & oranges- not even on the same axis of comfort. (And unlike fin-tube, cast iron is still delivering a fairly linear response with temp with 100F water.)

But then, in the one case you're talking $12-15 per foot, the other $40-60 per foot...

Maybe you are planning to set an electric infrared heater or some sort of alternative heating device in your home to facilitate warmth during the cold seasons. Or, maybe you want to just have a relaxing time at home lounging around in a sauna. Well, whatever the reason is for your heating plans, infrared heating is an element that you inevitably must consider in this type of technology today.

The IR or infrared heaters are actually made of thin and flat sheets. It also needs a large surface area to cover. If you get the tallest and the widest of these heaters, this will be the best at being efficient in meeting sauna needs