Measurement Guide

Use the map above to determine your region and compare to the chart below to find your application size.
80% AFUE Gas Furnace (Multi-Positional) Selection
Region 1 Region 2 Region 3 Region 4 Region 5 Furnace Model
690-860 740-925 830-1035 1005-1260 1125-1410
80G1--045
860-1290 925-1390 1035-1555 1260-1885 1410-2110 80G1--070
1290-1720 1390-1855 1555-2070 1885-2515 2110-2815 80G1--090
1720-2145 1855-2315 2070-2590 2515-3145 2815-3520 80G1--110
2145-2575 2315-2780 2590-3105 3145-3770 3520-4225 80G1--135
Residential Sizing: The table and charts are intended to be used as a guideline for Residential applications only.
The information is based on conventional window space (<15%), insulation and building construction (8 ft.
ceiling height). When including a finished basement, use 1/2 of the finished basement square footage with
the rest of the area being calculated.
Mobile/Manufactured Home Sizing: Refer to the Date Plate located in the electrical box or kitchen cabinets. For
further assistance, call Hamilton's customer service department [phone].
Square Footage
ROYALTON Equipment Sizing Guide