Im almost 60. But with a child's curiosity... or maybe for me, just ignorance : ) ?

I've grown up with hot water radiators, then steam radiators for a while then back to hot water radiators. I've always felt the exhaust from the funraces / boilers and same for the gas powered hot water heaters.... that the exhaust was pretty hot and that's why it goes up a brick / lined chimney.

My daughter's buying a new house. we were there recently checking out the progress. She has forced hot air heating system.

I've heard of using PVC exhausts for newer systems, but hadn't seen one in person.

Checking her system... yep, 1 'standard'? white PVC line bringing in outside cold air. And another PVC pipe running out the basement that, when I put my hand on it, was warm. Not even hot.

Furnaces these days are THAT efficient!? Is that the same for hot water radiator systems?

Is that as neat as I;m thinking it is!? or even older systems exhausts really not that much hotter?

 

Those are 90%+ efficient condensing furnaces. Been around since the 1980s. Standard 80% units are still around and available.
Condensing boilers are available as well.

 

As mentioned that is a condensing furnace. It is more efficient but comes with it's own set of problems. It should be checked and cleaned at least every other year.