SEER ratings are used to indicate a heating or cooling unit's efficiency (the higher the SEER rating, the more efficient the unit). Armstrong's 4SHP14LE heat pump offers a 14 SEER rating and their 4SHP16LT offers a 16 SEER rating. Goodman's SSZ14 heat pump offers a 14 SEER rating and their SSZ16 model offers a 16 SEER rating.
The largest Armstrong 4SHP14LE and 4SHP16LT heat pumps measure 35.75 inches deep by 37.75 inches in width and 43.75 inches in height. The largest Goodman SSZ14 and SSZ16 heat pumps measure 35.5 inches in depth by 35.5 wide by 38.5 inches high.
British thermal units (BTUs) measure the heat energy given off by a heating or cooling unit in one hour's time. Armstrong's 4SHP14LE can pump out up to 54,000 BTUs while the 4SHP16LT offers up to 59,000 BTUs. The Goodman SSZ14 offers up to 59,000 BTUs per hour and the SSZ16 offers up to 57,000 BTUs per hour.