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Basis of Design Overview

The Basis of Design section contains project-wide settings that affect how HVAKR calculates loads, airflows, and equipment sizing. These settings establish the design parameters for your project.

Basic project details including name, description, building type, and project contacts. This information appears on reports and helps organize your projects.

Weather station selection and design conditions. HVAKR uses ASHRAE weather data to determine outdoor design temperatures for heating and cooling calculations.

Define the thermal properties of your building envelope:

  • Wall types with U-values and construction details
  • Window types with solar heat gain coefficients
  • Roof types with insulation values
  • Slab types with F-factors for perimeter heat loss
  • Door types with U-values and infiltration behavior

Configure typical space characteristics:

  • Occupancy density (people per square foot)
  • Equipment and lighting loads
  • Usage schedules
  • Exhaust requirements

Define project-wide system design parameters:

  • A system description for reports
  • Duct types with sizing criteria (max velocity, max pressure drop, max height, liner thickness)
  • Register criteria per space type (register models and max flow rate, velocity, and NC for supply, return, and exhaust)

Manage floor plan drawings:

  • Upload PDF or DXF files
  • Calibrate scale for accurate measurements
  • Organize sheets by floor or building area

Changes to the Basis of Design automatically update calculations throughout your project:

  • Weather changes affect heating and cooling loads
  • Envelope properties affect transmission losses and solar gains
  • Space type changes affect internal gains and ventilation requirements
  • System type changes affect airflow and equipment sizing
  1. Configure weather first - This ensures accurate design conditions
  2. Define envelope types - Set up wall, window, and roof types before modeling
  3. Create space types - Define typical spaces for your building type
  4. Set up system types - Configure HVAC systems before assigning to spaces

Two mechanisms help you avoid re-entering common configurations:

  • ASHRAE libraries - Wall, window, and roof types can be populated from built-in ASHRAE construction libraries
  • Templates - When creating a project, enable Include Space Type Templates to start from space types used in projects you have access to