comparison: as … as / than
The pair as … as versus than after a comparative.
Use as … as for equal degree: as long as the brief, as soon as possible. Use than after a comparative: longer than the brief. Do not use as long than or longer as. After different, prefer from or than, not as.
Examples
UseThe hall is as cold as the porch.
UseThe hall is colder than the porch.
AvoidThe hall is colder as the porch.