[SparkyRnD]

Describing groups of rows as a core is an industry standard term. What has come to be the generally accepted definition is that a core is a linear group of rows of tubes. A 1 core radiator has a single row of horizontal or vertical tubes, a 2 core has two, etc. Within each row there can be any number of tubes depending on manufacturer.

People also need to understand that original style brass & copper radiators use 1/2" thick cores, so a 4-core brass & copper radiator has four rows of 1/2" thick tubes, for a total core thickness of 2". The aluminum units we build uses two rows of 1" thick tubes, for a total core thickness of 2". We state that our radiators are the same thickness as a standard 4 core.