Occupant Load

The occupantload object models internal residential heat gains from people in a house. It inherits from residential_enduse and contributes a heat load to the parent house based on occupant count, occupancy fraction, and per-person heat gain assumptions.

occupantload is a heat-centric end use. It does not model a detailed electrical appliance profile; instead, it provides thermal gains that affect house thermodynamics.

Model behavior

Parent and attachment requirements

• occupantload must be parented to a house or house_e object.
• During initialization, it attaches its end-use structure to the parent via attach_enduse().

Defaults and bounds

• number_of_occupants defaults to 4 when unspecified.
• heatgain_per_person defaults to 400 Btu/h (DOE-2 based assumption).
• At runtime, heatgain_per_person is bounded to [0, 1600] Btu/h. Values outside this range are reset to 400 Btu/h.
• number_of_occupants less than 0 is reset to 0.
• occupancy_fraction less than 0 is reset to 0.
• If occupancy_fraction * number_of_occupants exceeds 300, occupancy is reset to 0 as a sanity guard.

Heat gain calculation

The internal heat gain applied to the house is

If no explicit shape mode is used (shape.type == MT_UNKNOWN), this equation is evaluated directly during sync.

Properties

The following inherited residential_enduse fields are relevant:

• load.heatgain
• shape / schedule linkage

Example

object occupantload {
  name house1_occ;
  parent house1;
  number_of_occupants 3;
  occupancy_fraction OCCUPANCY_SCHEDULE*1.0;
  heatgain_per_person 380 Btu/h;
}

This example adds occupancy-driven internal heat gains to house1 using a schedule-defined occupancy profile.