Packaged Units
Packaged units are the most widely applied equipment
today in commercial facilities. This is primarily due to their
simple design and application flexibility along with a low installed
costs. Available in sizes from 1-1/2-tons to over 100-tons, packaged
units are very versatile. With self-contained, direct expansion
cooling and gas, electric resistance or reverse cycle heat, chances
are there is a packaged unit to meet your project requirements.
Components are pre-engineered, tested and rated at
the factory reducing the amount of design, application and installation
services required in the field. This improves reliability and
reduces both first and installed costs.
There are several considerations which should be
made when utilizing packaged units due to their limitations.
Packaged units generally have a shorter life than applied or split
systems. Since the entire unit is usually located outdoors on
a roof, they are subjected to the elements such as sun, rain,
hail and wind as well as corrosion from airborne substances such
as salt and acid rain. This often causes a more rapid deterioration
of internal components over time. The other disadvantage of packaged
units is they often must be replaced as an entire unit rather
than component by component. For example, when a gas heat exchanger
deteriorates it may be more expensive in parts and labor to replace
than simply changing the entire unit out. Especially when you
consider the improved energy efficiency of newer equipment.
Overall, packaged units are very popular due to their low installed cost and are modular and allow zoning of the building by unit rather than having to run expensive ductwork and and piping throughout the building. A life-cycle cost analysis should be performed to assess the impacts of first cost, installed cost, operating cost, equipment life, replacement cost and service costs. Carrier has computer software available to assist with these types of analyses.