If unmet load hour appear to be happening equally across your model use the Sizing:parameters object to oversize your entire hvac system to meet the peak loads.
If the problem appears to be isolated to a single thermal zone you can use the section highlighted below in the sizing:zone object to increase the capacity for just the zone in question.
Sizing:Zone,
f1:airlineops216, !- Zone or ZoneList Name
SupplyAirTemperature, !- Zone Cooling Design Supply Air Temperature Input Method
12.8, !- Zone Cooling Design Supply Air Temperature {C}
, !- Zone Cooling Design Supply Air Temperature Difference {deltaC}
SupplyAirTemperature, !- Zone Heating Design Supply Air Temperature Input Method
32.0, !- Zone Heating Design Supply Air Temperature {C}
, !- Zone Heating Design Supply Air Temperature Difference {deltaC}
0.0085, !- Zone Cooling Design Supply Air Humidity Ratio {kgWater/kgDryAir}
0.0080, !- Zone Heating Design Supply Air Humidity Ratio {kgWater/kgDryAir}
SZ DSOA F1:AIRLINEOPS216,!- Design Specification Outdoor Air Object Name
, !- Zone Heating Sizing Factor
, !- Zone Cooling Sizing Factor
DesignDay, !- Cooling Design Air Flow Method
, !- Cooling Design Air Flow Rate {m3/s}
, !- Cooling Minimum Air Flow per Zone Floor Area {m3/s-m2}
, !- Cooling Minimum Air Flow {m3/s}
, !- Cooling Minimum Air Flow Fraction
DesignDay; !- Heating Design Air Flow Method
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Nino Letti wrote:
>
> I´m having the same problem.
>
> 2013/1/25 JFCS
>
> > **
> >
> >
> > Still can't figure this out, how do you properly manage your setpoint?
> >
> >
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, jeannieboef wrote:
> > >
> > > Fan Pressure should have zero bearing on unmet loads. Its only
> > > function is to calculate electricity consumption. even though the
> > > motor heat will enter the airstream if it is designated as being in
> > > the airstream, I doubt this is your problem.
> > >
> > > That being said, your method for baseline fan power sizing by
> > > adjustment of the pressure rise looks right.
> > >
> > > You are allowed 300 hours unmet load, as long as the design case also
> > > has 250 or more but less than 300 (deviation of 50), though proper
> > > setpoint management should keep you under 50 for a good model.
> > >
> > > Sent from my iPhone
> > >
> > > On 17.01.2013, at 10:15, "JFCS" wrote:
> > >
> > > > My model gains unmet load hours or time set point not met during
> > > > cooling operations, when even i increased fan pressure rise of my
> > > > fans.
> > > >
> > > > First I autosized a working model with complete hvac system for my
> > > > Baseline case as per "G3.1.2.8 Design Airflow Rates". Then I need to
> > > > adjust my VAV's fan power as "G3.1.2.9 System Fan Power" therefore I
> > > > need to increase the pressure rise of my fans. Thought i got the
> > > > correct fan power but the unmet load hours is below 300hours...
> > > >
> > > > Any suggestions?
> > > >
> > > >
> > >
> >
> >
> >
>