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9 years ago This model has a number of problems. One of the issues below, however, is due
to a bug in the v3a software. When buildings have parking garage spaces, this
bug caused a error in specifying the baseline HVAC system. This bug has been
fixed in v3b(Beta). In order to avoid this issue, I ran the model using the
latest developer version of the model, and got a number of error messages in
the log file.
1. Warning: AirSystem 'AH-1A1B2' is Type = 'VAV', but the ControlMethod for Fan
'AH1A RETURN FAN' is not 'VariableSpeedDrive'. – The supply fan is variable
speed, but the return fan is constant speed. I am unsure how this
configuration will affect the simulation. This warning is repeated for
AirSystem 'AH-3A3B4'.
2. Error: AirSystem 'P1 GAR EXH' is a parking garage ventilation/exhaust
system with 'COControl', but the ControlMethod for Fan 'GEF-1' is not
'VariableSpeedDrive'. This is an error that must be corrected either by
removing the COControl or making the fan variable speed. This error is
repeated for systems 'P3L2 GAR EXH', 'P2 GAR EXH', and 'PL3 GAR EXH'.
3. There are 26 thermal zones with the following error, Error: ThermalZone 'P1
Office' has a design exhaust flow > 0, but the system fan power of exhaust
system 'AH-1C EXH' is 0. I recommend removing exhaust flow from zones unless
specific exhaust fans are being specified. In those cases, the fan properties
(flow, static pressure, efficiencies) need to be specified.
4. Error: ThermalZone 'L13 PHOUSE 1 2' is 'Unconditioned' but is served by a
Primary or Ventilation system with heating and/or cooling; this is not
currently permitted. This error is repeated for zone 'L13 PHOUSE 3 4'.
5. Error: The minimum design occupancy of ThermalZone 'P1 Garage Support' is
greater than 25 people/1000ft2, the ventilation system 'AH-3C' has an
economizer, and if is a multizone system, 'DDCToZone' control. Therefore,
'CO2Sensor' ventilation control (DCV) is likely mandatory for this zone. This
can be corrected by changing the ventilation Control Method to CO2Sensors.
However, the occupancy seems quite high for this space type, and reducing it
will also correct this error. This error is repeated for zones 'P2 Garage
Support', 'P2 Office', and 'L3 Bldg 3 4'.
6. Warning: Total min. primary air flow of terminal units served by Fan 'AH1A
SUPPLY FAN' is 59293.0, which is greater than the fan min. flow, 0.0. The fan
minimum flow should be increased to meet the required minimum. This warning is
repeated for fans 'AH1C SUPPLY FAN', 'AH3B SUPPLY FAN' and 'AH3C SUPPLY FAN'.
7. Warning: Total design exhaust flow for zones served by system 'P1 GAR EXH'
is 37538, which is greater than the system exhaust capacity, 36788.4. These
values should be corrected to be consistent. This warning is repeated for
systems 'P3L2 GAR EXH', 'P2 GAR EXH', 'PL3 GAR EXH', 'STAIR EXH BLDG 1 2',
'STAIR EXH BLDG 3 4', 'AH-1A1B2 EXH', 'AH-1C EXH', 'AH-3A3B4 EXH' and 'AH-3C
EXH'.
8. Warning: In Space 'L12 TENANT_L5000055', Skylit Daylighting Control Point:
Illuminance Set Point (0 lux ) is below minimum recommended for space type (75
lux ). This issue recurs for five additional spaces, some with setpoints of 50
lux.
9. Warning: Space 'P2 LOBBY_P2000006' has 7720 ft2 in the primary sidelit
daylit zone, but has 0 W of installed lighting assigned to the primary sidelit
daylit zone. The lighting power in the primary sidelit daylighting zone needs
to be corrected (user input of 0 watts). This issue recurs for 64 additional
spaces.
10. Warning: The ratio of minimum ventilation (outside) air to exhaust air
flow for BuildingStory 'P1' is < 1.0, indicating there is a flow imbalalance.
For every building story, the total exhaust flow must be less than or equal to
the minimum ventilation rate.
11. Warning: ThermalZone 'P1 Office' design ventilation flow is less than the
NACM minimum required flow for the zone. The minimum ventilation flow for the
zone must meet NACM requirements. This issue also occurs for zones 'P1 Garage
Support', 'P2 Garage Support', 'P2 Office', and 'L3 Bldg 3 4'.
Other issues observed with the model were that is a chilled water system with
chillers and cooling towers, but there are no cooling coils.
Three of the fluid systems, CHW Loop, HW Loop and CW Loop have multiple primary
supply and primary return fluid segments. Configurations like this are not
known to simulate correctly (nor do I know that they will not). I recommend
that only one each primary supply and primary return fluid segments be assigned
to each fluid system with only one pump (total )on the primary segments. More
than one pump can only be assigned to the fluid system for a primary loop or as
children of the primary equipment (chiller, boiler, tower) instead of the one
pump on the primary segments.
I believe that the message below about “Fraction of Zone controlled by the
Daylighting reference points is < 1.0” is just a warning. The zone in
question includes many spaces, including Electrical, Mechanical, Telephone
Rooms, so I am not surprised that less than 100% of the zone is daylit. Also,
since the simulation is performed using thermal zones where the data for the
spaces are averaged into the thermal zone, only two daylighting control points
are available to control the daylighting in all the spaces. This is a
limitation of EnergyPlus. Adding thermal zones such that fewer spaces are
included in each may improve daylight modeling, albeit at the expense of added
simulation time.
The issue with ‘Surface "P3000018_W34" overlaps SubSurface "P3000018_W3-W0"
‘ has to do with a window not being completely within its parent surface.
Looking at the polyloop coordinates for the surface and subsurface reveals that
the two edges of the subsurface match edges of the surface. It is safer if the
window is defined to be clearly inside the wall surface, even if only by 1 in.
(or 1 cm, if you prefer).
Original comment by rhedr...@archenergy.com on 27 Feb 2015 at 12:43
- Changed state: WontFix
Original issue reported on code.google.com by
f.le...@gmail.comon 26 Jan 2015 at 10:30Attachments: