29 October 2007

Microchannel heat exchangers


The air conditioning industry faces a
constant challenge to provide higher
effi ciency levels and greater equipment
reliability. This challenge is
even more diffi cult to meet when the
goal is simultaneously to maintain
equipment size and limit potential
cost impact.
Previous engineering solutions designed
to satisfy these requirements
have typically included such changes
as improving individual components
(e.g. higher effi ciency compressors)
or increasing the overall heat transfer
surface area (e.g. a larger coil) to
boost thermal performance. However,
each of these enhancements tends
to increase equipment size, cost, or
both.
An alternative solution for air conditioning
applications is microchannel
heat exchanger (MCHX) technology
for condenser coil design. This heat
exchanger technology has been widely
used in the automotive industry
for many years, with considerable
success. When compared to traditional
coil technology, microchannel
technology benefi ts include:
– Heat transfer and thermal performance
improved by 10%
– 20% lower air-side pressure drop
– Refrigerant charge reduced by between
20 and 40%
– 50% reduction of coil weight
– Increased reliability as a result of
better corrosion resistance
– No increase in chiller cost