At the risk of making this a converstion with myself, there's more...

"In the U.S. four compressor manufacturers offer products for use in
residential air
conditioners: Bristol (a division of York), Copeland (a division of
Emerson Electric), Tecumseh, and
Scroll Technologies (a joint venture between Bristol and Carlysle,
which itself is a division of
Carrier). Bristol and Copeland are the dominant firms. Bristol's
product line is limited to
reciprocating compressors, which use pistons to compress the
refrigerant. Reciprocating compressors
have the longest history and have a reputation for reliability.
Copeland offers reciprocating
compressors, but is known more for its line of scroll compressors.
Instead of pistons, scroll
compressors use interlocking helixes to compress the refrigerant in a
continuous action. Tecumseh
and Scroll Technologies are less prominent. Although it offers both
types of compressor, Tecumseh
supplies mainly reciprocating and rotary compressors in smaller air
conditioners and refrigerators.
Scroll Technologies is effectively Bristol's scroll division and is
capable of supplying only scroll
compressors."
(http://www.eere.energy.gov/buildings.../chap8_mia.pdf)

The Heil is using the same Copeland compressor.