[BLDG-SIM] DOE2 - Modeling Radiant H&C and DOAS with Cooling Boost

[Glenn M Hansen]

I'm working on a university building project which is made up of
office and classroom space. The HVAC system is designed with 4 pipe
radiant heating and cooling ceiling panels and a dedicated outside air
(DOA) ventilation fan, i.e. at 8,500 cfm. The DOA air is relieved out
the building and not returned. The DOA system is variable volume because
terminal units (no reheat) are used to shut off the room ventilation air
if the light occupancy sensor doesn't detect activity in the room. The
normal DOA SAT is 70F, which is neutral to room temperature setpoint.
This description is all pretty standard stuff, well here is the twist.
The DOA system has been up sized to carry some of the summer cooling
load, i.e. 12,000 cfm. The DOA cooling coil has also been sized to reset
the SAT down to 52F if the building average temperature is over 76F
(adjustable). This setting will probable get driven lower once the O&M
staff take over the building, i.e 72-74F. The local thermostat modulates
the terminal unit airflow from the minimum ventilation setting to the
maximum "cooling boost" setting. 

So the question is, what is the best DOE2 system choice to model the
radiant heating/cooling ceiling panels and DOA as described above? The
energy analyst has started with FC units with fan energy set to zero and
using ventilation command OS-FROM-SYSTEM. Ventilation air is assigned
from a VAV system with 100% OSA. What are other people typically using
to model this system? Which DOE2 system choice or technique would best
capture the "cooling boost" energy penalty? I'm also concerned
that potential radiant reheat energy will not be captured when the DOA
is switched into the "cooling boost" mode and there is no cooling
demand in some of the zones, i.e. zones located in the basement. Any
thoughts?


Glenn Hansen, P.E.
Mechanical / Energy Systems Engineer 
Oregon Department of Energy 
625 Marion St NE
Salem, Oregon 97301
1-800-221-8035 - in Oregon only
(503) 373-7562 - direct 

glenn.m.hansen at state.or.us 


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