Dear friend,
Would you please help me to understand this sentences below better and why it happen ?

In any system, whether it is new or old, measurably
higher pressure drops in the discharge line need to be
taken into consideration in sizing the condenser and
compressor. For example, if there was to be an 8 psi
(56kPa) pressure drop in discharge line of an NH3
system, it would amount to about a 2.5°F (1.4°C)
reduction in saturation temperature at the condenser.
This means that either the condenser should be
increased in size approximately 15 percent.

Why more pressure drop on discharge pipe force us to have bigger condenser ?

Sincerely yours.