(Heating, Ventilation and Air Conditioning, (pronounced "H-V-
A-C" is an acronym that stands for "heating, ventilation, and
air conditioning". HVAC is sometimes referred to as "climate
control" and is particularly important in the design of medium
to large industrial and office buildings such as sky scrapers
and in marine environments such as aquariums, where humidity and
temperature must all be closely regulated whilst maintaining
safe and healthy conditions within. In certain regions (e.g.,
UK) the term "Building Services" is also used, but may also
include plumbing and electrical systems. Refrigeration is
sometimes added to the field's abbreviation as HVAC&R or HVACR,
or ventilation is dropped as HACR (such as the designation of
HACR-rated circuit breakers). Heating, ventilation, and air
conditioning is based on the basic principles of thermodynamics,
fluid mechanics, and heat transfer, and to inventions and
discoveries made by Sadi Carnot, and many others. The invention
of the components of HVAC systems go