On Mon, 24 Dec 2007 09:15:54 +0000, Huge wrote:

On 2007-12-23, andrew heggie wrote:

the flue passage as a heat exchanger, a bit like roman hypercausts.

Not a flame(!), but it's "hypocaust".

No it's christmas ;-) and I think you are right but:

Hypocaust would be the bit under the floor, I think the flue passages also
ran up the walls and I have seen a square flue wall tile described as a
hypercaust but that equally may have been wrong. I was describing a
vertical chimney breast that was designed to absorb heat and then slowly
release it to the room.

I know the derivation of hyper and hypo but whence "caust"? Caustic is
used to describe alkaline substances that burn. I'll have to remeber to
look one day.

AJH