| Number of timesteps per hour
|
Sets the default number of simulations per hour.
|
| Loads convergence tolerance
|
Sets the default loads convergence tolerance, which
represents the value at which loads must agree before reaching convergence. The
loads convergence tolerance value is a fraction of the total load.
|
| Temperature convergence tolerance
|
Sets the default temperature convergence tolerance,
which represents the value at which zone temperatures must agree before
reaching convergence.
|
| Min. number of warmup days
|
Sets the default minimum number of warm up days
before
OpenBuildings Energy Simulator checks for
convergence. If convergence is achieved, the simulation can start. The default
of 6 is typical, and is usually enough to avoid false convergences and thus to
produce enough temperature and flux history to start the simulation.
|
| Max. number of warmup days
|
Sets the default maximum number of warm up days
that can be run before reaching convergence. The default of 25 is a typical
number used for this task; however, some complex buildings (with complex
constructions) may require more warmup days. A notification is issued if the
simulation runs out of days and has not yet converged. The maximum value can
be increased if this occurs.
|
| Internal convection heat transfer
|
Heat transfer from internal surfaces is computed by
considering convection and radiation separately. The default modelling methods
used for convection heat transfer coefficients can be specified for new
projects.
-
ASHRAE simple — Sets as the default, the
ASHRAE simple modeling standard, which uses fixed values of internal convection
coefficients, as defined in the ASHRAE Guide.
- ASHRAE
detailed — Sets as the default, the ASHRAE detailed modeling
standard, which computes heat transfer coefficients depending on the
temperature difference between the air temperature and the particular surface
temperature, as detailed in ASHRAE Guide.
|
| External convection heat transfer
|
Heat transfer from external surfaces is computed by
considering convection and radiation separately. The default modeling methods
used for convection heat transfer coefficients can be specified for new
projects.
- ASHRAE simple
— Sets as the default, the ASHRAE simple modeling standard, which uses fixed
values of external convection coefficients, as defined in the ASHRAE Guide.
- ASHRAE
detailed — Sets as the default, the ASHRAE detailed modeling
standard, which computes external heat transfer coefficients based on wind
speed as defined in the ASHRAE Guide.
|
| Infiltration model
|
For room infiltration, two models are available, a
simple air change rate and a multi-zone air flow model.
-
Simple — Sets the simple model as the
default for new projects, which enables you to simply define an air change rate
for each room and this simple air change rate is used in design and energy
calculations.
-
Multi-zone air flow — Sets the
multi-zone air flow model as the default for new projects, which computes the
air flow into, out of and between rooms by analyzing air movement through
cracks, joints, trickle ventilators, open windows and doors, roof ventilators
and many other flowpaths between rooms. In order to use the multi-zone air flow
model, you must have set up air flow paths for each room.
|
| Shadow calculation frequency
|
Sets the default time intervals for shadow
calculations to occur per design day.
|
| Max figures in shadow overlap calculations
|
Sets a default upper limit on the number of
overlapping shadows on a single surface allowed on shadow calculations.
|
| Heat balance algorithm
|
Sets the default type of heat and moisture transfer
algorithm used across the building construction calculations. The drop-down
list contains these algorithms:
-
CoductionTransferFunction — Sets
CoductionTransferFunction as the default algorithm. CTF is used to calculate
conduction heat transfer in building cooling/heating loads and energy
calculations.
-
MoisturePenetrationDepthConductionTransferFunction
— Sets MoisturePenetrationDepthConductionTransferFunction as the default
algorithm. MoisturePenetrationDepthConductionTransferFunction is a sensible
heat diffusion and an inside surface moisture storage algorithm that needs
additional moisture material property information.
-
ConductionFiniteDifference *1 Very slow
— Sets ConductionFiniteDifference *1 Very slow as the default algorithm.
ConductionFiniteDifference *1 Very slow is a sensible heat only solution that
does not account for moisture storage or diffusion.
-
CombinedHeatAndMoistureFiniteElement *2 Very very
slow — Sets CombinedHeatAndMoistureFiniteElement *2 Very very slow
as the default algorithm. CombinedHeatAndMoistureFiniteElement *2 Very very
slow is a coupled heat and moisture transfer and storage algorithm that uses
finite differences in constructions and requires further material properties.
|
| Heating Sizing Factor
|
Sets a default global heating sizing ratio that is
applied to all of the zone design heating loads and air flow rates.
|
| Cooling Sizing Factor
|
Sets a default global cooling sizing ratio that is
applied to all of the zone design cooling loads and air flow rates.
|
| Timesteps in averaging window
|
Sets the default number of load timesteps in the
zone design flow sequence averaging window. The default is 1, in which case the
calculated zone design flow rates are averaged over the load timestep.
|
| Inside temperature
|
Sets the default inside temperature for the
building as a whole, which is used for dew point calculations.
|
| Ground temperature: January - December
|
Ground floors are assumed to be in contact with the
earth, for which default temperatures can be set for each month of the year.
|
| Consider shading from recesses
|
When on by default, recesses around windows that
can partially shade the glazing are considered for simulation.
|
| Consider shading from fins
|
When on by default, fins defined for each window
are included in the shading calculations.
|
| Consider shading from external buildings
|
When on by default, buildings set up as part of the
shading calculation are considered.
|
| Consider external reflections
|
When on by default, the reflections from external
buildings are considered.
|
| Consider full internal sun distribution
|
When on by default, heat energy transmitted into the
building that is uniformly distributed to all internal surfaces apart from the
ceiling is considered.
|
