1 Erratum to: Heat Mass Transfer DOI 10.1007/s00231-006-0207-6

The original version of this article unfortunately contained a mistake.

The presentation of Eqs. (19) and (20) was incorrect. The correct versions are given below.

$$ \frac{{s_{{{\text{opt}}}} }} {L} = 3.53Ra_{L} ^{{ - 1/4}} $$
(19)
$$ {\left( {\ifmmode\expandafter\dot\else\expandafter\.\fi{Q}_{{{\text{c}}_{{\max }} }} = {\left( {\ifmmode\expandafter\dot\else\expandafter\.\fi{Q}_{0} } \right)}_{{\text{c}}} } \right)} + 0.125Ra_{L} ^{{1/2}} kH\Delta T{\left( {\frac{W} {L}} \right)} $$
(20)