The Natural Philosopher wrote:

All this is very odd. Anybody over about 55 will remember huge coke
fired classroom stoves

STOVES.

Not open fires.

In the 60s we used to heat a large house with coke for the stove and
coal for the open fires. We lived out in the sticks and in winter
deliveries of fuel could get erratic. The coke bunker took four tonnes
so we generally had lots of coke when the coal had run out. Open coke
fires were common and although they didn't give as much heat as the coal
they worked well in an open grate.

The local bowling club used to run a barbecue which was fuelled using
coke in large open pits. Less draft than an open fire and the coke still
burned well.