These building descriptors apply to slab-on-grade floors that are in direct contact with the ground.
| Slab Floor Name | |
| Applicability | All slab floors, optional |
|---|---|
| Definition | A unique name or code that relates the exposed floor to the construction documents. |
| Units | Text, unique |
| Input Restrictions | None |
| Baseline Rules | Not applicable |
| Slab Floor Type | |
| Applicability | All slab floors, required |
|---|---|
| Definition | One of two classes for floors in contact with ground. The classes are: 1) heated slab-on-grade floors and 2) unheated slab-on-grade floors. Heated slab-on-grade floors include all floors that are heated directly in order to provide heating to the space. Unheated slab-on-grade floors are all other floors in contact with ground. See the baseline standards and the associated User's Manuals for additional definition. |
| Units | List: heated or unheated |
| Input Restrictions | None |
| Baseline Rules | Unheated |
| Slab Floor Geometry | |
| Applicability | All slab floors, required |
|---|---|
| Definition | A geometric construct representing a slab floor in contact with the earth. The geometric representation can vary depending on how the energy simulation software models slabs-on-grade. Some models require that only the perimeter of the slab be entered. Other models divide the slab into a perimeter band within 2 ft of the edge and the interior portion or core area, such that the perimeter area and the core area sum to the total area of the slab. |
| Units | Data structure: as appropriate for the simulation tool |
| Input Restrictions | No restrictions |
| Baseline Rules | Same as baseline building |
| Slab Floor Construction | |
| Applicability | All slab floors, required input |
|---|---|
| Definition |
A description of how the slab is insulated (or not). How the construction is described will depend on the energy simulation model. Simple models may include just an F-factor, representing an instantaneous heat loss/gain to outside air. The F-factor could be related to the configuration of insulation in the proposed design. Other slab loss models may require that the surface area of the slab floor be divided between the perimeter and the interior. The insulation conditions then define heat transfer between both outside air and ground temperature. The insulation condition for slabs includes the R-value of the insulation and the distance it extends into the earth at the slab edge and how far it extends underneath the slab. |
| Units | Data structure: depends on the model that is used |
| Input Restrictions | If the perimeter method is used to model the slab, F-factors shall be taken from Appendix A of ASHRAE Standard 90.1-2001 or ASHRAE Standard 90.1-2007. For all methods, inputs shall be consistent with the construction documents. |
| Baseline Rules | Slab loss shall be modeled in the same manner in the baseline building as in the proposed design, e.g. if the perimeter method is used for the proposed design, the same method shall be used for the baseline building. The configuration of insulation and the F-factors for the baseline building are shown in [bookref id="baseline-building-f-factor-criteria-for-slab-on-grade-floors"]. If the perimeter method is not used, then the F-factors from the table shall be used in the baseline building. If an alternative modeling method is used, then inputs to the method for the baseline building shall be consistent with the insulation configuration described in [bookref id="baseline-building-f-factor-criteria-for-slab-on-grade-floors"]. |
[table title="Baseline Building F-factor Criteria for Slab-on-Grade Floors" id="baseline-building-f-factor-criteria-for-slab-on-grade-floors"]
| Applicable Standard | Condition | Space Category | Climate Zone | Baseline Building | |
| Insulation Configuration | F-Factor | ||||
| 90.1 – 2001 | Unheated | Nonresidential | 1-7 | NR | 0.730 |
| 8 | R-10 for 24 in. vertical | 0.540 | |||
| Residential | 1-6 | NR | 0.730 | ||
| 7 | R-10 for 24 in. vertical | 0.540 | |||
| 8 | R-15 for 24 in. vertical | 0.520 | |||
| Semi-Heated | 1- 8 | NR | 0.730 | ||
| Heated | Nonresidential | 1- 4 | R-7.5 for 12 in. vertical | 1.020 | |
| 5- 7 | R-10 for 36 in. vertical | 0.840 | |||
| 8 | R-10 for 48 in. vertical | 0.780 | |||
| Residential | 1- 3 | R-7.5 for 12 in. vertical | 1.020 | ||
| 4, 5 | R-10 for 36 in. vertical | 0.840 | |||
| 6- 8 | R-10 for 48 in. vertical | 0.780 | |||
| Semi-Heated | 1- 7 | R-7.5 for 12 in. vertical | 1.020 | ||
| 8 | R-7.5 for 24 in. vertical | .0950 | |||
| 90.1 – 2007 | Unheated | Nonresidential | 1-5 | NR | 0.730 |
| 6 | R-10 for 24 in. vertical | 0.540 | |||
| 7,8 | R-15 for 24 in. vertical | 0.520 | |||
| Residential | 1- 3 | NR | 0.730 | ||
| 4, 5 | R-10 for 24 in. vertical | 0.540 | |||
| 6, 7 | R-15 for 24 in. vertical | 0.520 | |||
| 8 | R-20 for 24 in. vertical | 0.510 | |||
| Semi-Heated | 1- 8 | NR | 0.730 | ||
| Heated | Nonresidential | 1, 2 | R-7.5 for 12 in. vertical | 1.020 | |
| 3 | R-10 for 24 in. vertical | 0.900 | |||
| 4- 6 | R-15 for 24 in. vertical | 0.860 | |||
| 7 | R-20 for 24 in. vertical | 0.843 | |||
| 8 | R-20 for 48 in. vertical | 0.688 | |||
| Residential | 1, 2 | R-7.5 for 12 in. vertical | 1.020 | ||
| 3 | R-10 for 24 in. vertical | 0.900 | |||
| 4, 5 | R-15 for 24 in. vertical | 0.860 | |||
| 6- 8 | R-20 for 48 in. vertical | 0.688 | |||
| Semi-Heated | 1- 6 | R-7.5 for 12 in. vertical | 1.020 | ||
| 7, 8 | R-10 for 24 in. vertical | 0.900 | |||
These building descriptors apply to slab-on-grade floors that are in direct contact with the ground.
| Slab Floor Name | |
| Applicability | All slab floors, optional |
|---|---|
| Definition | A unique name or code that relates the exposed floor to the construction documents. |
| Units | Text, unique |
| Input Restrictions | None |
| Baseline Rules | Not applicable |
| Slab Floor Type | |
| Applicability | All slab floors, required |
|---|---|
| Definition | One of two classes for floors in contact with ground. The classes are: 1) heated slab-on-grade floors and 2) unheated slab-on-grade floors. Heated slab-on-grade floors include all floors that are heated directly in order to provide heating to the space. Unheated slab-on-grade floors are all other floors in contact with ground. See the baseline standards and the associated User's Manuals for additional definition. |
| Units | List: heated or unheated |
| Input Restrictions | None |
| Baseline Rules | Unheated |
| Slab Floor Geometry | |
| Applicability | All slab floors, required |
|---|---|
| Definition | A geometric construct representing a slab floor in contact with the earth. The geometric representation can vary depending on how the energy simulation software models slabs-on-grade. Some models require that only the perimeter of the slab be entered. Other models divide the slab into a perimeter band within 2 ft of the edge and the interior portion or core area, such that the perimeter area and the core area sum to the total area of the slab. |
| Units | Data structure: as appropriate for the simulation tool |
| Input Restrictions | No restrictions |
| Baseline Rules | Same as baseline building |
| Slab Floor Construction | |
| Applicability | All slab floors, required input |
|---|---|
| Definition |
A description of how the slab is insulated (or not). How the construction is described will depend on the energy simulation model. Simple models may include just an F-factor, representing an instantaneous heat loss/gain to outside air. The F-factor could be related to the configuration of insulation in the proposed design. Other slab loss models may require that the surface area of the slab floor be divided between the perimeter and the interior. The insulation conditions then define heat transfer between both outside air and ground temperature. The insulation condition for slabs includes the R-value of the insulation and the distance it extends into the earth at the slab edge and how far it extends underneath the slab. |
| Units | Data structure: depends on the model that is used |
| Input Restrictions | If the perimeter method is used to model the slab, F-factors shall be taken from Appendix A of ASHRAE Standard 90.1-2007. For all methods, inputs shall be consistent with the construction documents. |
| Baseline Rules | Slab loss shall be modeled in the same manner in the baseline building as in the proposed design, e.g. if the perimeter method is used for the proposed design, the same method shall be used for the baseline building. The configuration of insulation and the F-factors for the baseline building are shown in [bookref id="baseline-building-f-factor-criteria-for-slab-on-grade-floors"]. If the perimeter method is not used, then the F-factors from the table shall be used in the baseline building. If an alternative modeling method is used, then inputs to the method for the baseline building shall be consistent with the insulation configuration described in [bookref id="baseline-building-f-factor-criteria-for-slab-on-grade-floors"]. |
[table title="Baseline Building F-factor Criteria for Slab-on-Grade Floors" id="baseline-building-f-factor-criteria-for-slab-on-grade-floors"]
| Applicable Standard | Condition | Space Category | Climate Zone | Baseline Building | |
| Insulation Configuration | F-Factor | ||||
| 90.1 – 2007 | Unheated | Nonresidential | 1-5 | NR | 0.730 |
| 6 | R-10 for 24 in. vertical | 0.540 | |||
| 7,8 | R-15 for 24 in. vertical | 0.520 | |||
| Residential | 1- 3 | NR | 0.730 | ||
| 4, 5 | R-10 for 24 in. vertical | 0.540 | |||
| 6, 7 | R-15 for 24 in. vertical | 0.520 | |||
| 8 | R-20 for 24 in. vertical | 0.510 | |||
| Semi-Heated | 1- 8 | NR | 0.730 | ||
| Heated | Nonresidential | 1, 2 | R-7.5 for 12 in. vertical | 1.020 | |
| 3 | R-10 for 24 in. vertical | 0.900 | |||
| 4- 6 | R-15 for 24 in. vertical | 0.860 | |||
| 7 | R-20 for 24 in. vertical | 0.843 | |||
| 8 | R-20 for 48 in. vertical | 0.688 | |||
| Residential | 1, 2 | R-7.5 for 12 in. vertical | 1.020 | ||
| 3 | R-10 for 24 in. vertical | 0.900 | |||
| 4, 5 | R-15 for 24 in. vertical | 0.860 | |||
| 6- 8 | R-20 for 48 in. vertical | 0.688 | |||
| Semi-Heated | 1- 6 | R-7.5 for 12 in. vertical | 1.020 | ||
| 7, 8 | R-10 for 24 in. vertical | 0.900 | |||
These building descriptors apply to slab-on-grade floors that are in direct contact with the ground.
| Slab Floor Name | |
| Applicability | All slab floors, optional |
|---|---|
| Definition | A unique name or code that relates the exposed floor to the construction documents. |
| Units | Text, unique |
| Input Restrictions | None |
| Baseline Rules | Not applicable |
| Slab Floor Type | |
| Applicability | All slab floors, required |
|---|---|
| Definition | One of two classes for floors in contact with ground. The classes are: 1) heated slab-on-grade floors and 2) unheated slab-on-grade floors. Heated slab-on-grade floors include all floors that are heated directly in order to provide heating to the space. Unheated slab-on-grade floors are all other floors in contact with ground. See the baseline standards and the associated User's Manuals for additional definition. |
| Units | List: heated or unheated |
| Input Restrictions | None |
| Baseline Rules | Unheated |
| Slab Floor Geometry | |
| Applicability | All slab floors, required |
|---|---|
| Definition | A geometric construct representing a slab floor in contact with the earth. The geometric representation can vary depending on how the energy simulation software models slabs-on-grade. Some models require that only the perimeter of the slab be entered. Other models divide the slab into a perimeter band within 2 ft of the edge and the interior portion or core area, such that the perimeter area and the core area sum to the total area of the slab. |
| Units | Data structure: as appropriate for the simulation tool |
| Input Restrictions | No restrictions |
| Baseline Rules | Same as baseline building |
| Slab Floor Construction | |
| Applicability | All slab floors, required input |
|---|---|
| Definition |
A description of how the slab is insulated (or not). How the construction is described will depend on the energy simulation model. Simple models may include just an F-factor, representing an instantaneous heat loss/gain to outside air. The F-factor could be related to the configuration of insulation in the proposed design. Other slab loss models may require that the surface area of the slab floor be divided between the perimeter and the interior. The insulation conditions then define heat transfer between both outside air and ground temperature. The insulation condition for slabs includes the R-value of the insulation and the distance it extends into the earth at the slab edge and how far it extends underneath the slab. |
| Units | Data structure: depends on the model that is used |
| Input Restrictions | If the perimeter method is used to model the slab, F-factors shall be taken from Appendix A of ASHRAE Standard 90.1-2007. For all methods, inputs shall be consistent with the construction documents. |
| Baseline Rules | Slab loss shall be modeled in the same manner in the baseline building as in the proposed design, e.g. if the perimeter method is used for the proposed design, the same method shall be used for the baseline building. The configuration of insulation and the F-factors for the baseline building are shown in Table 6.5.9-1. If the perimeter method is not used, then the F-factors from the table shall be used in the baseline building. If an alternative modeling method is used, then inputs to the method for the baseline building shall be consistent with the insulation configuration described in Table 6.5.9-1. |
Table 6.5.9-1: Baseline Building F-factor Criteria for Slab-on-Grade Floors
| Applicable Standard | Condition | Space Category | Climate Zone | Baseline Building | |
| Insulation Configuration | F-Factor | ||||
| 90.1 – 2007 | Unheated | Nonresidential | 1-5 | NR | 0.730 |
| 6 | R-10 for 24 in. vertical | 0.540 | |||
| 7,8 | R-15 for 24 in. vertical | 0.520 | |||
| Residential | 1- 3 | NR | 0.730 | ||
| 4, 5 | R-10 for 24 in. vertical | 0.540 | |||
| 6, 7 | R-15 for 24 in. vertical | 0.520 | |||
| 8 | R-20 for 24 in. vertical | 0.510 | |||
| Semi-Heated | 1- 8 | NR | 0.730 | ||
| Heated | Nonresidential | 1, 2 | R-7.5 for 12 in. vertical | 1.020 | |
| 3 | R-10 for 24 in. vertical | 0.900 | |||
| 4- 6 | R-15 for 24 in. vertical | 0.860 | |||
| 7 | R-20 for 24 in. vertical | 0.843 | |||
| 8 | R-20 for 48 in. vertical | 0.688 | |||
| Residential | 1, 2 | R-7.5 for 12 in. vertical | 1.020 | ||
| 3 | R-10 for 24 in. vertical | 0.900 | |||
| 4, 5 | R-15 for 24 in. vertical | 0.860 | |||
| 6- 8 | R-20 for 48 in. vertical | 0.688 | |||
| Semi-Heated | 1- 6 | R-7.5 for 12 in. vertical | 1.020 | ||
| 7, 8 | R-10 for 24 in. vertical | 0.900 | |||
These building descriptors apply to slab-on-grade floors that are in direct contact with the ground. 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.
|
Slab Floor Name |
|
|---|---|
|
Applicability |
All slab floors, optional |
|
Definition |
A unique name or code that relates the exposed floor to the construction documents. |
|
Units |
Text, unique |
|
Input Restrictions |
None |
|
Baseline Rules |
Not applicable |
|
Slab Floor Type |
|
|---|---|
|
Applicability |
All slab floors, required |
|
Definition |
One of two classes for floors in contact with ground. The classes are: 1) heated slab-on-grade floors and 2) unheated slab-on-grade floors. Heated slab-on-grade floors include all floors that are heated directly in order to provide heating to the space. Unheated slab-on-grade floors are all other floors in contact with ground. |
|
Units |
List: heated or unheated |
|
Input Restrictions |
None |
|
Baseline Rules |
The baseline building slab floor is unheated. |
|
Slab Floor Geometry |
|
|---|---|
|
Applicability |
All slab floors, required |
|
Definition |
A geometric construct representing a slab floor in contact with the earth. The geometric representation can vary depending on how the energy simulation software models slabs-on-grade. Some models require that only the perimeter of the slab be entered. Other models divide the slab into a perimeter band within 2 ft of the edge and the interior portion or core area, such that the perimeter area and the core area sum to the total area of the slab. |
|
Units |
Data structure: as appropriate for the simulation tool which may include area, perimeter or other information |
|
Input Restrictions |
No restrictions |
|
Baseline Rules |
Same as baseline building |
|
Slab Floor Construction |
|
|---|---|
|
Applicability |
All slab floors, required input |
|
Definition |
A description of how the slab is insulated (or not). How the construction is described will depend on the energy simulation model. Simple models may include just an F-factor, representing an instantaneous heat loss/gain to outside air. The F-factor could be related to the configuration of insulation in the proposed design. Other slab loss models may require that the surface area of the slab floor be divided between the perimeter and the interior. The insulation conditions then define heat transfer between both outside air and ground temperature. The insulation condition for slabs includes the R-value of the insulation and the distance it extends into the earth at the slab edge and how far it extends underneath the slab. |
|
Units |
Data structure: depends on the model that is used |
|
Input Restrictions |
If the perimeter method is used to model the slab, F-factors shall be taken from Appendix A of ASHRAE Standard 90.1-2013. For all methods, inputs shall be consistent with the construction documents. |
|
Baseline Rules |
Slab loss shall be modeled in the same manner in the baseline building as in the proposed design, e.g. if the perimeter method is used for the proposed design, the same method shall be used for the baseline building. |
Table 3.5.9-1: Baseline Building F-factor Criteria for Slab-on-Grade Floors
|
|
Nonresidential |
Residential |
Semi-Heated |
|||
|
Climate Zone |
Name |
F-factor |
Name |
F-factor |
Name |
F-factor |
|
1 |
NR |
0.730 |
NR |
0.730 |
NR |
0.730 |
|
2 |
||||||
|
3 |
||||||
|
4 |
||||||
|
5 |
||||||
|
6 |
||||||
|
7 |
R-10 for 24 in. v |
0.540 |
||||
|
8 |
R-10 for 24 in. v |
0.540 |
R-15 for 24 in. v |
0.520 |
||
These building descriptors apply to slab-on-grade floors that are in direct contact with the ground.
|
Slab Floor Name |
|
|
Applicability |
All slab floors, optional |
|
Definition |
A unique name or code that relates the exposed floor to the construction documents |
|
Units |
Text: unique |
|
Input Restrictions |
None |
|
Baseline Building |
Not applicable |
|
Slab Floor Type |
|
|
Applicability |
All slab floors, required |
|
Definition |
One of two classes for floors in contact with ground. The classes are: 1. Heated slab-on-grade floors 2. Unheated slab-on-grade floors Heated slab-on-grade floors include all floors that are heated directly to provide heating to the space. Unheated slab-on-grade floors are all other floors in contact with the ground. |
|
Units |
List: Heated or Unheated |
|
Input Restrictions |
None |
|
Baseline Building |
The baseline building slab floor type is unheated |
|
Slab Floor Geometry |
|
|
Applicability |
All slab floors, required |
|
Definition |
A geometric construct representing a slab floor in contact with the earth. The geometric representation can vary depending on how the energy simulation software models slabs-on-grade. Some models require that only the perimeter of the slab be entered. Other models divide the slab into a perimeter band within 2 ft of the edge and the interior portion or core area, such that the perimeter area and the core area sum to the total area of the slab. |
|
Units |
Data structure: as appropriate for the simulation tool This may include: area, perimeter exposed |
|
Input Restrictions |
As designed |
|
Baseline Building |
The geometry of the slab floor in the baseline building is identical to the slab floor in the proposed design |
|
Slab Floor Construction |
|
|
Applicability |
All slab floors, required input |
|
Definition |
A specification containing a series of layers that result in a construction assembly for the proposed design. The first layer in the series represents the outside (or exterior) layer and the last layer represents the inside (or interior) layer. See the building descriptors above for slab floor type. A description of how the slab is insulated (or not). How the construction is described will depend on the energy simulation model. The construction can be represented by an F-factor that represents the entire construction (floor and insulation). Simple models may include just an F-factor, representing an instantaneous heat loss/gain to outside air. The F-factor could be related to the configuration of insulation in the proposed design. Other slab loss models may require that the surface area of the slab floor be divided between the perimeter and the interior. The insulation conditions then define heat transfer between both outside air and ground temperature. The insulation condition for slabs includes the R-value of the insulation and the distance it extends into the earth at the slab edge and how far it extends underneath the slab. |
|
Units |
List (depends on the model that is used) For F-factor method: F-factor from Standard 90.1-2019 Normative Appendix A, Table A6.3.1; this is one selection from list 1 and one selection from list 2. Note that some combinations from list 1 and list 2 are not allowed – see Normative Appendix A, Table A6.3.1. List 1: None, 12 in horizontal, 24 in horizontal, 36 in horizontal, 48 in horizontal, 12 in vertical, 24 in vertical, 36 in vertical, 48 in vertical, Fully insulated slab List 2: R-0, R-5, R-7.5, R-10, R-15, R-20, R-25, R-30, R-35, R-40, R-45, R-50, R-55 |
|
Input Restrictions |
For new construction, F-factors shall be taken from Table A6.3.1 of Standard 90.1-2019, Normative Appendix A for both heated slab floors and unheated slab floors. For all methods, inputs shall be consistent with the construction documents. For alterations the same requirements apply. |
|
Baseline Building |
Slab loss shall be modeled in the same manner in the baseline building as in the proposed design. Slab loss can be modeled with the simple method (F-factor) for unheated slabs. A layer-by-layer input can also be used. The base assembly is a slab floor of 6-inch concrete poured directly onto the earth (Concrete 140lb/ft3 – 6 in.), the bottom of the slab is at grade line and soil conductivity is 0.75 Btu/h-ft °F. The configuration of insulation and the F-factors for the baseline building unheated slab floors are shown in Table A6.3 in Normative Appendix A. The F-factors for the baseline building have been listed in the table below. |
Table 36. Baseline Building Slab on Grade Envelope Requirements
|
Climate Zone |
Non Residential |
Residential |
Semi-Heated |
|||
|
Insulation |
F-Factor |
Insulation |
F-Factor |
Insulation |
F-Factor |
|
|
Climate Zone 1 |
NR |
0.73 |
NR |
0.73 |
NR |
0.73 |
|
Climate Zone 2 |
NR |
0.73 |
NR |
0.73 |
NR |
0.73 |
|
Climate Zone 3 |
NR |
0.73 |
NR |
0.73 |
NR |
0.73 |
|
Climate Zone 4 |
NR |
0.73 |
NR |
0.73 |
NR |
0.73 |
|
Climate Zone 5 |
NR |
0.73 |
NR |
0.73 |
NR |
0.73 |
|
Climate Zone 6 |
NR |
0.73 |
NR |
0.73 |
NR |
0.73 |
|
Climate Zone 7 |
NR |
0.73 |
R-10 for 24 in. vertical |
0.54 |
NR |
0.73 |
|
Climate Zone 8 |
R-10 for 24 in. vertical |
0.54 |
R-15 for 24 in. vertical |
0.52 |
NR |
0.73 |
These building descriptors apply to slab-on-grade floors that are in direct contact with the ground.
| Slab Floor Name | |
| Applicability | All slab floors, optional |
|---|---|
| Definition | A unique name or code that relates the exposed floor to the construction documents. |
| Units | Text, unique |
| Input Restrictions | None |
| Slab Floor Geometry | |
| Applicability | All slab floors, required |
|---|---|
| Definition | A geometric construct representing a slab floor in contact with the earth. The geometric representation can vary depending on how the energy simulation software models slabs-on-grade. Some models require that only the perimeter of the slab be entered. Other models divide the slab into a perimeter band within 2 ft of the edge and the interior portion or core area, such that the perimeter area and the core area sum to the total area of the slab. |
| Units | Data structure: as appropriate for the simulation tool |
| Input Restrictions | No restrictions |
| Slab Floor Construction | |
| Applicability | All slab floors, required input |
|---|---|
| Definition |
A description of how the slab is insulated (or not). How the construction is described will depend on the energy simulation model. Simple models may include just an F-factor, representing an instantaneous heat loss/gain to outside air. The F-factor could be related to the configuration of insulation in the proposed design. Other slab loss models may require that the surface area of the slab floor be divided between the perimeter and the interior. The insulation conditions then define heat transfer between both outside air and ground temperature. The insulation condition for slabs includes the R-value of the insulation and the distance it extends into the earth at the slab edge and how far it extends underneath the slab. |
| Units | Data structure: depends on the model that is used |
| Input Restrictions | If the perimeter method is used to model the slab, F-factors shall be taken from Appendix A of ASHRAE Standard 90.1-2001 or ASHRAE Standard 90.1-2007. For all methods, inputs shall be consistent with the construction documents. |
These building descriptors apply to slab-on-grade floors that are in direct contact with the ground.
| Slab Floor Name | |
| Applicability | All slab floors, optional |
|---|---|
| Definition | A unique name or code that relates the exposed floor to the construction documents. |
| Units | Text, unique |
| Input Restrictions | None |
| Slab Floor Geometry | |
| Applicability | All slab floors, required |
|---|---|
| Definition | A geometric construct representing a slab floor in contact with the earth. The geometric representation can vary depending on how the energy simulation software models slabs-on-grade. Some models require that only the perimeter of the slab be entered. Other models divide the slab into a perimeter band within 2 ft of the edge and the interior portion or core area, such that the perimeter area and the core area sum to the total area of the slab. |
| Units | Data structure: as appropriate for the simulation tool |
| Input Restrictions | No restrictions |
| Slab Floor Construction | |
| Applicability | All slab floors, required input |
|---|---|
| Definition |
A description of how the slab is insulated (or not). How the construction is described will depend on the energy simulation model. Simple models may include just an F-factor, representing an instantaneous heat loss/gain to outside air. The F-factor could be related to the configuration of insulation in the proposed design. Other slab loss models may require that the surface area of the slab floor be divided between the perimeter and the interior. The insulation conditions then define heat transfer between both outside air and ground temperature. The insulation condition for slabs includes the R-value of the insulation and the distance it extends into the earth at the slab edge and how far it extends underneath the slab. |
| Units | Data structure: depends on the model that is used |
| Input Restrictions | If the perimeter method is used to model the slab, F-factors shall be taken from Appendix A of ASHRAE Standard 90.1-2001 or ASHRAE Standard 90.1-2007. For all methods, inputs shall be consistent with the construction documents. |