Previous (Heating Load Calculation and Results)   |   Start   |   Next (Overheating calculation)

Cooling load calculation and results

 Go to the Simulation tab

 Open cooling load calculation setup

👉  Choose variable for which the cooling load calculation should search the maximum value, in this example Max heat removed (from air and room unit).

👉  Define percentage of internal loads (percentage of all loads as defined) for cooling load calculation (normally 100% should be used)

 Select synthetic weather

Note: With synthetic weather, outdoor temperatures are taken from design day data, i.e. extremely hot days that have been stored for each month of the year. For each month, the hot design day is repeated over and over, until the building has adapted as it would during a very long hot spell.

 Run cooling load calculation. For the Standard edition, the Cooling Load Report is automatically displayed after the simulations. For the Expert edition, the Summary tab is displayed first. If you run the Expert edition, revert back to the Simulation tab and open the relevant Report link.

Note: If you click the More button, more options are shown. Here you can limit the cooling load calculation to a single month or to selected months. You can also adapt the severity of the design day used. By default, the most severe conditions are selected.

Note: Selection of ‘Design period using climate file’ makes instead the cooling load calculation based on a measured hot spell from a climate file.

Note: The multi-simulation procedure described above assumes that full climate data, including monthly design days, are available for the location. Should the Location object only contain a single summer design day, only this will be simulated.

Cooling load results:

For each zone:

• Heat removed: This is – during the cooling load calculation period – the maximum sensible and latent heat removed from the zone by all air flows and room units.
• Time: The time for the given peak. Note that the report collects results from all of the different simulations that have been done to find the worst day for each zone, i.e. the peak may occur at different months for different zones.
• Room unit cool: This is the maximum sensible and latent heat removed from the zone by all room units.
• Dry vent cool: This is the maximum sensible heat removed by the mechanical ventilation. The sum of ‘Room unit cool’ and ‘Dry vent cool’ is not equal to ‘Heat removed’, since the heat load due to infiltration as well as the latent heat removed by the mechanical ventilation are not included in ‘Dry vent cool’.
• Temp.: This is the dry bulb air temperature at the time of maximum heat removal. Make sure that this fulfills the required setpoint; otherwise, the cooling units didn’t have sufficient capacity.
• Sup airflow: This is the mechanical supply air flow rate at the time of maximum heat removal.

For each air handling unit:

• Cooling: The maximum cooling provided by the cooling coil(s), both sensible and latent.
• Time: The time for the coil peak. Note that this peak often occurs at a different time than zone peaks, since solar radiation has limited impact on the AHU load.
• AHU cold recovery: The maximum recovered cooling from the return air stream.

For the building:

• Zone cooling: Maximum cooling power delivered by the plant to room units.
• AHU cooling: Maximum cooling power delivered by the plant to the air handling units.
• Total: Maximum cooling power to both zones and AHUs.
• Time: Time when the total building cooling power peaks.

 Select ‘Summary’ within the Simulation tab. (For the Expert edition, the Summary tab is already open.)

 Visualize Room unit cool

Note: When moving the cursor over the box icons in the result column titles, a tooltip appears.

 Select ‘Details’ within the Simulation tab. (For the Expert edition, click instead on the Details tab.)

 Load data for the July simulation

Note: Immediately after a cooling load simulation, only some key results from each peak simulation are loaded to provide an overview of all peaks. However, to investigate detailed results (any variable), one must load a single peak case. This way, consistent results for the whole building for this hot day are displayed. Note that results for zones or systems that had their peak some other month also will be loaded.

 Go to result animation in the 3D tab

 Choose a variable (mean air temperature)

 Repeat for other variables

Note: You will get a selection of more variables as soon as you select more result output (see next exercise below)

 Activate shadow animation

 Open animation

 Start animation / pause animation

 Move within animation by dragging the scroll bar

👉  Alternatively change simulation time by typing time and day

 Change animation speed

 Leave result animation

Previous (Heating Load Calculation and Results)   |   Start   |   Next (Overheating calculation)