Chilled Beams vs High Performance VAV
Hello Friends and simulators-
We get an awful lot of questions about modeling new systems, and rightly so. These often involve workarounds and many people do these workarounds differently. (Example, how do I model VRF in eQUEST?).
What are some of these cool "new" systems:
- Chilled Beams
- Displacement Ventilation
- Underfloor Air Distribution
While all these systems have their own time and place, newer does not always mean better.
Before getting caught up in the hype of any new, flashy system, make sure that you don't disregard high performance technology in conventional systems (example high performance VAV).
This is a great read, by an HVAC genius, John Murphy, PhD.
A building simulation can show wondrous results. When chilled beams were first implemented in TRACE 700, it was surprising to see that Active chilled beams saved little, or no energy over VAV systems. I dug into this myself and found that the much larger fan, when unloading as is typical in a VAV system uses less energy than the smaller fan that does not unload in an active chilled beam system. Who would've have guessed?! This is a perfect example of why energy simulation is needed. The results are often counter-intuitive.
Of course, there are places where chilled beams may be a better application, but a simple energy simulation may surprise you on the fan power consumed!
And By the way, TRACE 700 can model all of these flashy systems OOB (out of the box = no workarounds). So, if you would like to do some of these test runs, maybe give TRACE 700 a try.