Water Outlet

The Water outlet component defines hot water consumption, delivery temperatures as well as any heat conduction and latent gains to zones. One or more Water outlets can be associated with a previously defined Water outlet group.

The way that Water outlets works in very different depending on whether you are using the Simple or Detailed HVAC Detailed HVAC Activity data setting.

Simple HVAC Activity data

 

When using Simple HVAC activity data one Water outlet component can be used to serve multiple zones very easily simply by selecting the zones on the Zones served tab. In this case DHW demand data from Activity and HVAC model data tabs is used to define the total hot water flow rate and schedule of consumption for the zones referenced in the Zones served tab.

Detailed HVAC Activity data

 

When using Detailed HVAC activity data option the Water outlet hot water consumption peak flow rate and time varying schedule are defined independently of any model data DHW settings and you must provide the peak hot water flow rate and schedule of operation for the Water outlet. This gives you the flexibility to define DHW consumption is various ways:

 

• Use one Water outlet for multiple zones. This approach can be used in cases where the usage pattern (schedule) is the same in each of the zones. In this case the total peak hot water flow rate for all the zones to be included can be calculated in a spreadsheet (for example) and the peak flow for all zones entered here on the Water outlet dialog.
• Use one Water outlet for each zone. This approach might be preferred when either the patterns of usage (schedules) for each zone is different and needs to be defined separately or when you prefer a more explicit separation of zones for a clearer representation in the model, rather than lumping all flows into a single Water outlet.
• Use one Water outlet for each physical water outlet in the building, e.g. one Water outlet for each hot water tap, shower etc. In this case you would need to calculate expected peak flow and schedules of usage for each outlet.

 

In all of the above cases it is usually more work to set up DHW input data when using the Detailed HVAC activity data than for the Simple HVAC activity alternative.

General

Name

Enter a unique name for the water outlet.

Target temperature schedule

Select a schedule defining the temperature of the water delivered from taps etc.

Flow Rate

Note: The data under the Flow Rate header is only shown when using the 2-Detailed HVAC Detailed HVAC Activity data setting.

Peak flow rate

The peak demanded hot water flow rate (in m3/s or gal/min). This value is multiplied by the Flow rate fraction schedule (below) to determine the actual volumetric flow rate at any time in the simulation. This value is only required when using the Detailed HVAC data model option.

Flow rate fraction schedule

Select the schedule specifying the flow rate fraction relative to the Peak flow rate (above). This value is only required when using the Detailed HVAC data model option.

Heat Gain to Zone

Heat gain to zone

Check this option if you wish to model sensible and/or latent heat transfer from the Water outlet to a zone in the building model.

Zone

Select the zone to receive sensible and/or latent loads from this water outlet.

Sensible Fraction Schedule Name

Select the schedule specifying the fraction of the maximum possible sensible heat gain (based on inlet water conditions and ambient zone conditions) that is added to the zone. Select schedule Off for no sensible load.

Latent Fraction Schedule Name

Select the schedule specifying the fraction of the maximum possible latent heat gain (based on inlet water conditions and ambient zone conditions) that is added to the zone. Select schedule Off for no latent load.

Zones Served

The Zones served tab on the Water outlet dialog is only visible when using the default 1-Simple HVAC Detailed HVAC Activity data setting. It allows you to select the zones served by this Water outlet. For these zones the actual hot water consumption rates used in the simulation are generated based on the DHW consumption rate set on the Activity tab and the DHW Operation schedule on the HVAC tab in the same way as for Simple HVAC.

Check the boxes of the zones to be served by this Water outlet as shown below.

Tip: You can use the checkboxes at building and block levels as a fast way to select/deselect all of the available zones in the building or block.

Note: Any zones selected on the Zones served tab will not consume hot water in the simulation if their DHW consumption rate is 0. This means that you can select all zones in a building without concern for generating DHW demand for unoccupied zones.