<P> where G r L (\ displaystyle \ mathrm (Gr) _ (L)) is the Grashof number . </P> <P> W.H. McAdams suggested the following correlations for horizontal plates . The induced buoyancy will be different depending upon whether the hot surface is facing up or down . </P> <P> For a hot surface facing up, or a cold surface facing down, for laminar flow: </P> <Dl> <Dd> h = k 0.54 R a L 1 / 4 L 10 5 <R a L <2 × 10 7 (\ displaystyle h \ = (\ frac (k0. 54 \ mathrm (Ra) _ (L) ^ (1 / 4)) (L)) \, \ quad 10 ^ (5) <\ mathrm (Ra) _ (L) <2 \ times 10 ^ (7)) </Dd> </Dl>

Convective heat transfer coefficient of water at 25 c