Class: OpenStudio::Model::SubSurface

Inherits:
Object
  • Object
show all
Defined in:
lib/openstudio-standards/standards/Standards.SubSurface.rb

Overview

open the class to add methods to apply HVAC efficiency standards

Instance Method Summary collapse

Instance Method Details

#component_infiltration_rate(type) ⇒ Double

Determine the component infiltration rate for this surface

Parameters:

  • type (String) —

    choices are ‘baseline’ and ‘advanced’

Returns:

  • (Double) —

    infiltration rate @units cubic meters per second (m^3/s)



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# File 'lib/openstudio-standards/standards/Standards.SubSurface.rb', line 9

def component_infiltration_rate(type)
  comp_infil_rate_m3_per_s = 0.0

  # Define the envelope component infiltration rates
  component_infil_rates_cfm_per_ft2 = {
    'baseline' => {
      'opaque_door' => 0.40,
      'loading_dock_door' => 0.40,
      'swinging_or_revolving_glass_door' => 1.0,
      'vestibule' => 1.0,
      'sliding_glass_door' => 0.40,
      'window' => 0.40,
      'skylight' => 0.40
    },
    'advanced' => {
      'opaque_door' => 0.20,
      'loading_dock_door' => 0.20,
      'swinging_or_revolving_glass_door' => 1.0,
      'vestibule' => 1.0,
      'sliding_glass_door' => 0.20,
      'window' => 0.20,
      'skylight' => 0.20
    }
  }

  boundary_condition = outsideBoundaryCondition
  # Skip non-outdoor surfaces
  return comp_infil_rate_m3_per_s unless outsideBoundaryCondition == 'Outdoors' || outsideBoundaryCondition == 'Ground'

  # Per area infiltration rate for this surface
  surface_type = subSurfaceType
  infil_rate_cfm_per_ft2 = nil
  case boundary_condition
  when 'Outdoors'
    case surface_type
    when 'Door'
      infil_rate_cfm_per_ft2 = component_infil_rates_cfm_per_ft2[type]['opaque_door']
    when 'OverheadDoor'
      infil_rate_cfm_per_ft2 = component_infil_rates_cfm_per_ft2[type]['loading_dock_door']
    when 'GlassDoor'
      OpenStudio.logFree(OpenStudio::Info, 'openstudio.Standards.Model', "For #{name}, assuming swinging_or_revolving_glass_door for infiltration calculation.")
      infil_rate_cfm_per_ft2 = component_infil_rates_cfm_per_ft2[type]['swinging_or_revolving_glass_door']
    when 'FixedWindow', 'OperableWindow'
      infil_rate_cfm_per_ft2 = component_infil_rates_cfm_per_ft2[type]['window']
    when 'Skylight', 'TubularDaylightDome', 'TubularDaylightDiffuser'
      infil_rate_cfm_per_ft2 = component_infil_rates_cfm_per_ft2[type]['skylight']
    end
  end
  if infil_rate_cfm_per_ft2.nil?
    OpenStudio.logFree(OpenStudio::Warn, 'openstudio.Standards.Model', "For #{name}, could not determine surface type for infiltration, will not be included in calculation.")
    return comp_infil_rate_m3_per_s
  end

  # Area of the surface
  area_m2 = netArea
  area_ft2 = OpenStudio.convert(area_m2, 'm^2', 'ft^2').get

  # Rate for this surface
  comp_infil_rate_cfm = area_ft2 * infil_rate_cfm_per_ft2

  comp_infil_rate_m3_per_s = OpenStudio.convert(comp_infil_rate_cfm, 'cfm', 'm^3/s').get

  # OpenStudio::logFree(OpenStudio::Debug, "openstudio.Standards.Model", "......#{self.name}, infil = #{comp_infil_rate_cfm.round(2)} cfm @ rate = #{infil_rate_cfm_per_ft2} cfm/ft2, area = #{area_ft2.round} ft2.")

  return comp_infil_rate_m3_per_s
end

#reduce_area_by_percent_by_raising_sill(percent_reduction) ⇒ Object

Reduce the area of the subsurface by raising the sill height.

to reduce the area.

Parameters:

  • percent_reduction (Double) —

    the fractional amount



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# File 'lib/openstudio-standards/standards/Standards.SubSurface.rb', line 116

def reduce_area_by_percent_by_raising_sill(percent_reduction)

  mult = 1 - percent_reduction

  # Calculate the original area
  area_original = netArea

  # Find the min and max z values
  min_z_val = 99999
  max_z_val = -99999
  vertices.each do |vertex|
    # Min z value
    if vertex.z < min_z_val
      min_z_val = vertex.z
    end
    # Max z value
    if vertex.z > max_z_val
      max_z_val = vertex.z
    end
  end

  # Calculate the window height
  height = max_z_val - min_z_val

  # Calculate the new sill height
  new_sill_z = max_z_val - (height * mult)    

  # Reset the z value of the lowest points
  new_vertices = []
  vertices.each do |vertex|
    new_x = vertex.x
    new_y = vertex.y
    new_z = vertex.z
    if new_z == min_z_val
      new_z = new_sill_z
    end
    new_vertices << OpenStudio::Point3d.new(new_x, new_y, new_z)
  end

  # Reset the vertices
  setVertices(new_vertices)

  return true
end

#reduce_area_by_percent_by_shrinking_toward_centroid(percent_reduction) ⇒ Object

Reduce the area of the subsurface by shrinking it toward the centroid. to reduce the area.

Parameters:

  • percent_reduction (Double) —

    the fractional amount

Author:

  • Julien Marrec



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# File 'lib/openstudio-standards/standards/Standards.SubSurface.rb', line 82

def reduce_area_by_percent_by_shrinking_toward_centroid(percent_reduction)
  mult = 1 - percent_reduction
  scale_factor = mult**0.5

  # Get the centroid (Point3d)
  g = centroid

  # Create an array to collect the new vertices
  new_vertices = []

  # Loop on vertices (Point3ds)
  vertices.each do |vertex|
    # Point3d - Point3d = Vector3d
    # Vector from centroid to vertex (GA, GB, GC, etc)
    centroid_vector = vertex - g

    # Resize the vector (done in place) according to scale_factor
    centroid_vector.setLength(centroid_vector.length * scale_factor)

    # Move the vertex toward the centroid
    vertex = g + centroid_vector

    new_vertices << vertex
  end

  # Assign the new vertices to the self
  setVertices(new_vertices)
end

#vertical_rectangle? ⇒ Boolean

Determine if the sub surface is a vertical rectangle, meaning a rectangle where the bottom is parallel to the ground.

Returns:

  • (Boolean) 


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# File 'lib/openstudio-standards/standards/Standards.SubSurface.rb', line 163

def vertical_rectangle?
  # Get the vertices once
  verts = vertices

  # Check for 4 vertices
  return false unless verts.size == 4

  # Check if the 2 lowest z-values
  # are the same
  z_vals = []
  verts.each do |vertex|
    z_vals << vertex.z
  end
  z_vals = z_vals.sort
  return false unless z_vals[0] = z_vals[1]

  # Check if the diagonals are equal length
  diag_a = verts[0] - verts[2]
  diag_b = verts[1] - verts[3]
  return false unless diag_a.length == diag_b.length

  # If here, we have a rectangle
  return true
end