INGENIEUR
‟
DOAS holds a lot of promise with its ability
to maintain the right humidity in all weather
conditions. The “divide and conquer” approach
definitely allows the designer to have better
management of the two key elements of air
conditioning, i.e. temperature and moisture.
CONCLUSION
The Indoor air quality requirement of higher
ventilation rates along with proper RH control and
energy management will push the HVAC designer
to the use of “Dedicated Outside Air System” in
the near future. DOAS holds a lot of promise
with its ability to maintain the right humidity in
all weather conditions. The “divide and conquer”
approach definitely allows the designer to have
better management of the two key elements of air
conditioning, i.e. temperature and moisture. The
original definition of air conditioning can now be
met in an energy efficient manner.
The DOAS has already proved itself with
high potential of energy savings in nearly all
applications and weather profiles. The benefits of
Options II, III and V over the first option in terms of
energy savings are significant. Otherwise from IAQ,
RH and energy points of view, Option V has been
proven to be the most cost effective.
However, in RH control the last three options
discussed have performed better for a wide variety
of applications and weather profiles. To clearly
state that a particular option is the best solution
would be a meaningless statement as proper
simulation exercises need to be conducted on a
few key applications for a few weather profiles and
a “first cost + operating cost” matrix tabulated,
giving due consideration to the importance of
RH control. Some studies have indicated that
the installed first cost of DOAS is lower than
conventional systems for certain applications.
6
38
VOL
2019
VOL 77
55 JANUARY–MARCH
JUNE 2013
REFERENCE
Dehumidification and cooling loads from
ventilation Air - Lewis Harriman, Plager D, Kosar D
Current Trends of Desiccant Technology uses in
commercial HVAC – Deepak Pahwa.
Heating, Ventilation, Air – Conditioning and
Refrigeration (HVAC & R) Engineering – Charles E,
Gulledge
Indoor Air Quality – Mould – EPA
Dehumidification Equipment advances – Lewis G
Harriman III and James Judge
Designing dedicated outdoor air systems – Stanley
A Mumma
Designing for Absolute moisture control – R. Mark
Nunnelly and J Patrick
ABC’s of DOAS – Wayne Morris
RX for sick buildings – John S Manuel
Initial Evaluation of Displacement Ventilation and
Dedicated Outdoor air system for US commercial
buildings – Steven J Emmerich and Tim Mc Dowell
White paper on sustainability – Robert Cassidy
Overview of integrating dedicated outdoor Air
system with parallel terminal systems – Stanley
A Mumma
A classroom solution using active chilled beams –
William Rafferty