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3.5.8 Below Grade Walls

Below Grade Wall Name
Applicability All projects, optional input
Definition A unique name that keys the below grade wall to the construction documents
Units Text, unique
Input Restrictions None
Baseline Rules Not applicable
Below Grade Wall Geometry
Applicability All projects
Definition A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width.
Units Data structure: below grade wall geometry
Input Restrictions There are no restrictions other than that the inputs shall be in agreement with the construction documents.
Baseline Rules The geometry of below grade walls in the baseline building is identical to the below grade walls in the proposed design.
Below Grade Wall Construction
Applicability All projects, required input
Definition A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions.
Units Data structure: construction assembly
Input Restrictions No restrictions other than that the inputs shall be in agreement with the construction documents.
Baseline Rules See [bookref id="baseline-building-c-factor-criteria-for-below-grade-walls"] and [bookref id="baseline-building-below-grade-wall-construction-assemblies"].

[table title="Baseline Building C-factor Criteria for Below-Grade Walls" id="baseline-building-c-factor-criteria-for-below-grade-walls"]

Applicable Standard Space Category Climate Zone Standard Design
Minimum Insulation C-Factor
90.1 - 2001 Nonresidential 1- 6 NR 1.140
7, 8 R-7.5 c.i. 0.119
Residential 1-5 NR 1.140
6- 8 R-7.5 c.i. 0.119
Semi-Heated 1-8 NR 1.140
90.1 - 2007 Nonresidential 1- 4 NR 1.140
5678 R-7.5 c.i. 0.119
Residential 1-3 NR 1.140
456 R-7.5 c.i. 0.119
7 R-10 c.i. 0.092
8 R-12.5 c.i. 0.075
Semi-Heated 1- 8 NR 1.140

[table title="Baseline Building Below-Grade Wall Construction Assemblies" id="baseline-building-below-grade-wall-construction-assemblies"]

Construction Layer Thickness (inch) Conductivity (Btu/h ft F) Density (lb/ft²) Specific Heat (Btu/lb F) R-value (ft²·°F·h/Btu) C-factor (Btu/ft²·°F·h)
NR 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87 1.140
R-7.5 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 1.8 0.02 1.8 0.29 7.50  
  Total assembly         8.37 0.119
R-10 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 2.4 0.02 1.8 0.29 10.00  
  Total assembly         10.87 0.092
R-12.5 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 3.0 0.02 1.8 0.29 12.50  
  Total assembly         13.37 0.075
90.1-2007
Below Grade Wall Name
Applicability All projects, optional input
Definition A unique name that keys the below grade wall to the construction documents
Units Text, unique
Input Restrictions None
Baseline Rules Not applicable
Below Grade Wall Geometry
Applicability All projects
Definition A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width.
Units Data structure: below grade wall geometry
Input Restrictions There are no restrictions other than that the inputs shall be in agreement with the construction documents.
Baseline Rules The geometry of below grade walls in the baseline building is identical to the below grade walls in the proposed design.
Below Grade Wall Construction
Applicability All projects, required input
Definition A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions.
Units Data structure: construction assembly
Input Restrictions No restrictions other than that the inputs shall be in agreement with the construction documents.
Baseline Rules See [bookref id="baseline-building-c-factor-criteria-for-below-grade-walls"] and [bookref id="baseline-building-below-grade-wall-construction-assemblies"].

[table title="Baseline Building C-factor Criteria for Below-Grade Walls" id="baseline-building-c-factor-criteria-for-below-grade-walls"]

Applicable Standard Space Category Climate Zone Standard Design
Minimum Insulation C-Factor
90.1 - 2007 Nonresidential 1- 4 NR 1.140
5678 R-7.5 c.i. 0.119
Residential 1-3 NR 1.140
456 R-7.5 c.i. 0.119
7 R-10 c.i. 0.092
8 R-12.5 c.i. 0.075
Semi-Heated 1- 8 NR 1.140

[table title="Baseline Building Below-Grade Wall Construction Assemblies" id="baseline-building-below-grade-wall-construction-assemblies"]

Construction Layer Thickness (inch) Conductivity (Btu/h ft F) Density (lb/ft²) Specific Heat (Btu/lb F) R-value (ft²·°F·h/Btu) C-factor (Btu/ft²·°F·h)
NR 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87 1.140
R-7.5 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 1.8 0.02 1.8 0.29 7.50  
  Total assembly         8.37 0.119
R-10 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 2.4 0.02 1.8 0.29 10.00  
  Total assembly         10.87 0.092
R-12.5 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 3.0 0.02 1.8 0.29 12.50  
  Total assembly         13.37 0.075
Below Grade Wall Name
Applicability All projects, optional input
Definition A unique name that keys the below grade wall to the construction documents
Units Text, unique
Input Restrictions None
Baseline Rules Not applicable
Below Grade Wall Geometry
Applicability All projects
Definition A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width.
Units Data structure: below grade wall geometry
Input Restrictions There are no restrictions other than that the inputs shall be in agreement with the construction documents.
Baseline Rules The geometry of below grade walls in the baseline building is identical to the below grade walls in the proposed design.
Below Grade Wall Construction
Applicability All projects, required input
Definition A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions.
Units Data structure: construction assembly
Input Restrictions No restrictions other than that the inputs shall be in agreement with the construction documents.
Baseline Rules See Table 6.5.8-1 and Table 6.5.8-2.

Table 6.5.8-1: Baseline Building C-factor Criteria for Below-Grade Walls

Applicable Standard Space Category Climate Zone Standard Design
Minimum Insulation C-Factor
90.1 - 2007 Nonresidential 1- 4 NR 1.140
5678 R-7.5 c.i. 0.119
Residential 1-3 NR 1.140
456 R-7.5 c.i. 0.119
7 R-10 c.i. 0.092
8 R-12.5 c.i. 0.075
Semi-Heated 1- 8 NR 1.140

Table 6.5.8-2: Baseline Building Below-Grade Wall Construction Assemblies

Construction Layer Thickness (inch) Conductivity (Btu/h ft F) Density (lb/ft²) Specific Heat (Btu/lb F) R-value (ft²·°F·h/Btu) C-factor (Btu/ft²·°F·h)
NR 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87 1.140
R-7.5 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 1.8 0.02 1.8 0.29 7.50  
  Total assembly         8.37 0.119
R-10 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 2.4 0.02 1.8 0.29 10.00  
  Total assembly         10.87 0.092
R-12.5 c.i. 115 lb/ft3 CMU, solid grout 8 0.45 115 0.20 0.87  
  R-10 continuous insulation 3.0 0.02 1.8 0.29 12.50  
  Total assembly         13.37 0.075

Heat transfer from below-grade walls may be modeled using a constant annual or monthly ground temperature. The temperatures from table 3.9.1-1 may be used as a default.

 

Below-Grade Wall Name

Applicability

All projects, optional input

Definition

A unique name that keys the below grade wall to the construction documents

Units

Text, unique

Input Restrictions

None

Baseline Rules

Not applicable

 

Below-Grade Wall Geometry

Applicability

All projects

Definition

A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width.

Units

Data structure: below grade wall geometry

Input Restrictions

There are no restrictions other than that the inputs shall be in agreement with the construction documents.

Baseline Rules

The geometry of below grade walls in the baseline building is identical to the below grade walls in the proposed design.

 

Below-Grade Wall Construction

Applicability

All projects, required input

Definition

A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions.

Units

Data structure: construction assembly

Input Restrictions

No restrictions other than that the inputs shall be in agreement with the construction documents.

Baseline Rules

See Table 3.5.8-1 and Table 3.5.8-2.

Table 3.5.8-1: Baseline Building C-factor Criteria for Below-Grade Walls

 

Nonresidential

Residential

Semi-Heated

Climate Zone

Name

C-factor

Name

C-factor

Name

C-factor

1

NR

1.140

NR

1.140

NR

1.140

2

3

4

5

6

R-7.5 ci

0.119

7

R-7.5 ci

0.119

8

 

Table 3.5.8-2: Baseline Building Below-Grade Wall Construction Assemblies

Construction

Layer

Thickness (inch)

Conductivity (Btu/h ft F)

Density (lb/ft²)

Specific Heat (Btu/lb F)

R-value (ft²·°F·h/Btu)

C-factor (Btu/ft²·°F·h)

NR

115 lb/ft3 CMU, solid grout

8

0.45

115

0.20

0.87

1.140

R-7.5 c.i.

115 lb/ft3 CMU, solid grout

8

0.45

115

0.20

0.87

 

 

R-10 continuous insulation

1.8

0.02

1.8

0.29

7.50

 

 

Total assembly

 

 

 

 

8.37

0.119

3.5.8 Fenestration

Note that fenestration includes windows, doors that have more than 50% glazed area, and skylights. A skylight is a fenestration that has a tilt of less than 60° from horizontal.

 

Fenestration Name

Applicability

All fenestration, optional input

Definition

A unique name or code that relates the fenestration to the design documents and a parent surface

Units

Text: unique

Input Restrictions

Not restrictions

Baseline Building

Not applicable

 

Vertical Fenestration Geometry and Area

Applicability

All fenestration

Definition

Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt are inherited from the parent surface. The details of how the coordinate system is implemented may vary between software programs.

Units

Data structure: opening

Input Restrictions

As designed. The defined fenestration should match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions:

  • Exterior shading is modeled from buildings, vegetation, and other objects. All elements whose effective height is greater than their distance from a proposed building and whose width facing the proposed building is greater than one-third that of the proposed building shall be accounted for in the analysis
  • If daylighting is modeled within the adjacent space.

Baseline Building

The geometry of the vertical fenestration shall be similar to the proposed design but each fenestration shall be increased or reduced in size in proportion to the proposed design size such that the overall fenestration area as a percentage of the above-grade exterior wall area is equal to the values in Table 28. For building areas not shown in Table 28, vertical fenestration areas shall equal that in the proposed design or 40% of gross above-grade wall area, whichever is smaller, and shall be distributed on each face of the building in the same proportions in the proposed design.

If the gross area of all windows (including framing) in each space conditioning category in the building exceeds the value specified in Table 28 of the gross above-grade exterior wall area for that building area type, the dimensions of each window shall be reduced such that the window to wall ration is equal to the value specified in Table 28. This reduction needs to be done by increasing the sill height until the limit is reached for each building area type.

If the WWR of the proposed building design is less than the value specified in Table 28, the dimensions of each window shall be increased equally from the center of the window until a wall or partition is reached. If window area needs to be increased further, then the sill height will be reduced will the maximum WWR limit is reached.The fenestration area for an existing building shall equal the existing fenestration area prior to the proposed work and shall be distributed on each face of the building in the same proportions as the existing building.

Table 28. Baseline Building Vertical Fenestration Area

Building Area Types(a)

Baseline Building Gross Above-Grade-Wall Area

Grocery Store

7%

Healthcare (outpatient)

21%

Hospital

27%

Hotel/motel (≤75 rooms)

24%

Hotel/motel (>75 rooms)

34%

Office (≤5000 ft2)

19%

Office (5000 to 50,000 ft2)

31%

Office (>50,000 ft2)

40%

Restaurant (quick service)

34%

Restaurant (full service)

24%

Retail (standalone)

11%

Retail (strip mall)

20%

School (primary)

22%

School (secondary and university)

22%

Warehouse (non-refrigerated)

6%

 

Horizontal Fenestration (Skylight) Geometry and Area

Applicability

All horizontal fenestration (skylights)

Definition

Fenestration geometry defines the position and dimensions of the fenestration surface within its parent surface and the identification of the parent surface. The orientation and tilt is inherited from the parent surface. The details of how the coordinate system is implemented may vary between rating software programs.

Units

Data structure: opening

Input Restrictions

There are no restrictions, other than a match with the construction drawings or as-built drawings. Specification of the fenestration position within its parent surface is required for the following conditions:

  • exterior shading is modeled from buildings, vegetation, other objects
  • if daylighting is modeled within the adjacent space.

Baseline Building

The geometry of the horizontal fenestration shall be equal to the proposed design or 3% of gross roof area, whichever is smaller.

If the skylight area of the proposed design exceeds 3%, the baseline skylight area shall be decreased by an identical percentage in all roof components in which skylights are located to reach 3%. Skylight orientation as tilt shall be the same as the proposed design.

 

Fenestration Construction

Applicability

All fenestration

Definition

A collection of values that together describe the performance of a fenestration system. The values that are used to specify the criteria are U-factor, solar heat gain coefficient (SHGC), and visible light transmittance (VT). U-factor and SHGC inputs are whole-window values.

Units

Data structure: shall include at a minimum the following properties as specified by NFRC ratings:

  • U-factor: whole window U-factor
  • SHGC: whole window solar heat gain coefficient
  • VT: visible transmittance

Input Restrictions

The U-factor, SHGC, and VT for fenestration shall be modeled as certified and labeled in accordance with NFRC 100, 200, and 300, respectively. Unlabeled skylights shall be assigned the U-factors in Standard 90.1-2019, Normative Appendix A, Table A8.1-1 for the SHGCs and Table A8.1-2 for VTs.

Unlabeled vertical fenestration, both operable and fixed, shall be assigned the U-factors, SHGCs, and VTs in Normative Appendix A, Table A8.2.

Baseline Building

The requirements for vertical fenestration U factor and SHGC are specified in Table 29 and Table 30 (Standard 90.1-2019 Tables G3.4-1 to Tables G3.4-8). The visible transmittance for horizontal and vertical fenestration is specified are specified in Table 32 and Table 33 (Standard 90.1-2019 Tables G3.4-1 to Tables G3.4-8).

Table 29. U-factor Requirement for Vertical and Horizontal Fenestration

Climate Zone

Nonresidential

Residential

Semi-Heated

Vertical

Horizontal

Vertical

Horizontal

Vertical

Horizontal

0 and 1

1.22

1.36

1.22

1.36

1.22

1.36

2

1.22

1.36

1.22

1.36

1.22

1.36

3

0.57

0.69

0.57

0.69

1.22

1.36

3C

1.22

1.36

1.22

1.36

1.22

1.36

4

0.57

0.69

0.57

0.58

1.22

1.36

5

0.57

0.69

0.57

0.69

1.22

1.36

6

0.57

0.69

0.57

0.58

1.22

1.36

7

0.57

0.69

0.57

0.69

1.22

1.36

8

0.46

0.58

0.46

0.58

1.22

0.81
                     

Table 30. SHGC Requirement for Vertical Fenestration

Climate Zone

Nonresidential

Residential

Semi-Heated

0-10%

10.1-20%

20.1-30%

30.1-40%

0-10%

10.1-20%

20.1-30%

30.1-40%

0-10%

0 and 1

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.40

2

0.25

0.25

0.25

0.25

0.39

0.25

0.25

0.25

0.40

3

0.39

0.25

0.25

0.25

0.39

0.39

0.25

0.25

0.40

3C

0.61

0.39

0.39

0.34

0.61

0.61

0.39

0.34

0.40

4

0.39

0.39

0.39

0.39

0.39

0.39

0.39

0.39

0.40

5

0.49

0.39

0.39

0.39

0.49

0.39

0.39

0.39

0.40

6

0.49

0.39

0.39

0.39

0.49

0.39

0.39

0.39

0.40

7

0.49

0.49

0.49

0.49

0.49

0.49

0.49

0.49

0.40

8

0.40

0.40

0.40

0.40

0.40

0.40

0.40

0.40

0.40

Table 31. SHGC Requirement for Horizontal Fenestration

Climate Zone

Nonresidential

Residential

Semi-Heated

0-2%

2.1-5%

0-2%

2.1-5%

0-2%

2.1-5%

0 and 1

0.36

0.19

0.19

0.19

0.55

0.55

2

0.36

0.19

0.19

0.19

0.55

0.55

3

0.39

0.19

0.36

0.19

0.55

0.55

3C

0.61

0.39

0.39

0.19

0.55

0.55

4

0.49

0.39

0.36

0.19

0.55

0.55

5

0.49

0.39

0.49

0.39

0.55

0.55

6

0.49

0.49

0.49

0.39

0.55

0.55

7

0.68

0.64

0.64

0.64

0.55

0.55

8

0.55

0.55

0.55

0.55

0.55

0.55
               

Table 32. VT Requirement for Vertical Fenestration

Climate Zone

Nonresidential

Residential

Semi-Heated

0-10%

10.1-20%

20.1-30%

30.1-40%

0-10%

10.1-20%

20.1-30%

30.1-40%

0-10%

0 and 1

0.28

0.28

0.28

0.28

0.28

0.28

0.28

0.28

0.44

2

0.28

0.28

0.28

0.28

0.28

0.28

0.28

0.28

0.44

3

0.43

0.28

0.28

0.28

0.43

0.43

0.28

0.28

0.44

3C

0.67

0.43

0.43

0.34

0.61

0.61

0.39

0.34

0.44

4

0.43

0.43

0.43

043

0.43

0.43

0.43

0.43

0.44

5

0.54

0.43

0.43

0.43

0.54

0.43

0.43

0.43

0.44

6

0.54

0.43

0.43

0.43

0.54

0.43

0.43

0.43

0.44

7

0.54

0.54

0.54

0.54

0.54

0.54

0.54

0.54

0.44

8

0.44

0.44

0.44

0.44

0.44

0.44

0.44

0.44

0.44

Table 33. VT Requirement for Horizontal Fenestration

Climate Zone

Nonresidential

Residential

Semi-Heated

0-2%

2.1-5%

0-2%

2.1-5%

0-2%

2.1-5%

0 and 1

0.40

0.21

0.21

0.21

0.61

0.61

2

0.40

0.21

0.21

0.21

0.61

0.61

3

0.43

0.21

0.40

0.21

0.61

0.61

3C

0.67

0.43

0.43

0.21

0.61

0.61

4

0.54

0.43

0.40

0.21

0.61

0.61

5

0.54

0.43

0.54

0.43

0.61

0.61

6

0.54

0.54

0.54

0.43

0.61

0.61

7

0.75

0.70

0.70

0.70

0.61

0.61

8

0.61

0.61

0.61

0.61

0.61

0.61
               

 

External Shading Devices

Applicability

All fenestration

Definition

Devices or building features that are documented in the construction documents and shade the glazing, such as overhangs, fins, shading screens, and setbacks of windows from the exterior face of the wall. Objects that shade the building but are not part of the building and parts of the building that cause the building to shade itself are also modeled, but are not a part of this building descriptor. The software shall be capable of modeling vertical fins and overhangs. Recessed windows may also be modeled with side fins and overhangs.

Units

Data structure: opening shade

Input Restrictions

No restrictions other than the inputs must match the construction documents

Baseline Building

The baseline building is modeled without external shading devices and as flush with the exterior wall

 

Internal Shading Devices

Applicability

All fenestration

Definition

Curtains, blinds, louvers, or other devices that are applied on the room side of the glazing material. Glazing systems that use blinds between the glazing layers are also considered internal shading devices. Glass coatings, components, or treatments of the glazing materials are addressed through the fenestration construction building descriptor.

Units

Data structure: indicates the type of control, or blind schedule if applicable

Input Restrictions

Manual fenestration shading devices such as blinds or shades may be modeled or not, but if they are, they are required to be modeled the same in the baseline building, so that there is no credit.

Automatically controlled fenestration shades or blinds may be modeled in the proposed design.

Baseline Building

Manual shades or blinds shall be modeled the same as in the proposed building.

Automatically controlled fenestration shades or blinds will not be modeled in the baseline building.

 

Dynamic Glazing

Applicability

Fenestration with dynamic glazing

Definition

Dynamic glazing can vary the SHGC and VT of the glazing in response to a signal from an energy management system, direct sunlight on the glazing, or other inputs

Units

Unitless

Input Restrictions

Dynamic glazing can be modeled for the proposed design and controlled according to sequences specified in the construction documents. If controlled manually, then the proposed model is required to use the average of the minimum and maximum SHGC and VT.

Baseline Building

Not applicable

 

SHGC Dim Fraction

Applicability

Fenestration with dynamic glazing

Definition

For dynamic glazing, this is the fraction of the SHGC when darkened to the SHGC during normal operation. This can be applied when the solar heat gain exceeds a specified threshold, or controlled by an electrical signal.

Units

Unitless

Input Restrictions

Between 0 and 1

Baseline Building

Not applicable

 

VT Dim Fraction

Applicability

Fenestration with dynamic glazing

Definition

For dynamic glazing, this is the fraction of the visible transmittance when darkened to the visible transmittance during normal operation. This can be applied when the solar heat gain exceeds a specified threshold, or controlled by an electrical signal.

Units

Unitless

Input Restrictions

Between 0 and 1

Baseline Building

Not applicable

 

Dynamic Solar Heat Gain Threshold

Applicability

Fenestration with automatically controlled dynamic glazing

Definition

For dynamic glazing, this is the solar heat gain threshold above which the dynamic glazing is active (darkened). When the solar heat gain drops below this threshold, the glazing is switched back to being inactive (clearest setting). Indoor and outdoor air temperatures (OATs) can also be used as setpoints for controlling the switchable solar heat gain threshold. This may be used in combination with the solar heat gain and illuminance thresholds for control. A flag may be used to indicate that this control is not used.

Units

Incident solar threshold (Btu/h-ft2)

Input Restrictions

As designed

Baseline Building

Not applicable

 

Switchable Space Temperature Threshold

Applicability

Fenestration with automatically controlled dynamic glazing

Definition

For dynamic glazing, this is the space temperature above which the dynamic glazing is active (darkened). When the space temperature drops below this threshold, the glazing is switched back to being inactive (clearest setting). Indoor and outdoor air temperatures are the setpoints required for controlling the dynamic solar heat gain threshold. This may be used in combination with the solar heat gain and illuminance thresholds for control. A flag may be used to indicate that this control is not used.

Units

°F

Input Restrictions

As designed

Baseline Building

Not applicable

 

Dynamic Illuminance Threshold

Applicability

Fenestration with automatically controlled dynamic glazing

Definition

For dynamic glazing, this is the illuminance threshold above which the dynamic glazing is regulated between active (darkened) and inactive (clearest setting). With a single illuminance setpoint, the dynamic glazing will adjust between the clearest and darkest setting to allow the desired illuminance level. A flag may be used to indicate that this control is not used.

Units

lux

Input Restrictions

As designed

Baseline Building

Not applicable

 

Dynamic Glazing Schedule

Applicability

Fenestration with dynamic glazing controlled by an electrical signal

Definition

For dynamic glazing, this is an hourly schedule for when the dynamic glazing is darkened, when controlled by an electrical signal

Units

Boolean: 1 if dynamic glazing is active (darkened); 0 if not active

Input Restrictions

0 or 1 for schedule values. As designed.

Baseline Building

Not applicable
Below Grade Wall Name
Applicability All projects, optional input
Definition A unique name that keys the below grade wall to the construction documents
Units Text, unique
Input Restrictions None
Below Grade Wall Geometry
Applicability All projects
Definition A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width.
Units Data structure: below grade wall geometry
Input Restrictions There are no restrictions other than that the inputs shall be in agreement with the construction documents.
Below Grade Wall Construction
Applicability All projects, required input
Definition A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions.
Units Data structure: construction assembly
Input Restrictions No restrictions other than that the inputs shall be in agreement with the construction documents.
Below Grade Wall Name
Applicability All projects, optional input
Definition A unique name that keys the below grade wall to the construction documents
Units Text, unique
Input Restrictions None
Below Grade Wall Geometry
Applicability All projects
Definition A geometric construct that describes the dimensions and placement of walls located below grade. Below grade walls have soil or crushed rock on one side and interior space on the other side. Some simulation models take the depth below grade into account when estimating heat transfer, so the geometry may include height and width.
Units Data structure: below grade wall geometry
Input Restrictions There are no restrictions other than that the inputs shall be in agreement with the construction documents.
Below Grade Wall Construction
Applicability All projects, required input
Definition A description of the manner in which a below grade wall is constructed or a representation of the thermal performance of the below grade wall that can be used by the energy simulation software to estimate heat transfer. The construction can be described as a C-factor which is similar to a U-factor, except that the outside air film is excluded or the construction can be represented as a series of layers, like exterior constructions.
Units Data structure: construction assembly
Input Restrictions No restrictions other than that the inputs shall be in agreement with the construction documents.