Complex sentence: The funnelling of heat and flames up a central flue is said to use the same principles as rocket stoves, with increased surface contact area maximises thermal transfer, leading to faster boiling while the upward chimney draft effect enables operation in windy or wet weather.
Split into simpler sentences: The funnelling of heat and flames up a central flue using the same principles as rocket stoves. The increased surface contact area maximises thermal transfer, leading to faster boiling while the upward chimney draft effect enables operation in windy or wet weather.