documentation

Carbonfly Toolbox Documentation

• Carbonfly Toolbox Documentation
  • Grasshopper toolbox
    • 01:Create
      • CreateCFCase
      • CreateCFGeometry
      • Carbonfly Info
    • 02:Boundary
      • Body
      • Dynamic Respiration
      • Dynamic Window
      • InletVelocity
      • internalFields
      • Outlet
      • RecircReturn
      • RecircSupply
      • Wall
    • 03:Recipe
      • controlDict
      • fvSchemes
      • fvSolution
      • Residual Control List
    • 04:Solution
      • blockMesh
      • runFoam
      • snappyHexMesh
      • surfaceFeatures
      • checkMesh
      • foamMonitor
    • 05:Util
      • Air Exchange Rate (Maas)
      • BSA (Du Bois)
      • CO2 generation rate
      • Gagge two-node model
      • Gagge two-node model (sleep)
      • Surface Wind Pressure
      • Manikin LOD 0
      • Met List
    • 06:Post-processing
      • internalProbes
      • postProcess
      • Read Results
      • CO2-based IAQ
      • Carbonfly IAQ Standards

Grasshopper toolbox

01:Create

CreateCFCase

Create Carbonfly case

Inputs	Outputs
case_dir (str): OpenFOAM case root folder	log (str): Log
case_name (str): Carbonfly case name	case_path (str): Carbonfly case path
CF_geo (from CreateCFGeometry): List of Carbonfly Geometry objects
unit (str): "mm" (default), "cm", "m", unit setting in Rhino -> STL will be scaled to meters on export
controlDict (from controlDict): Carbonfly controlDict
fvSchemes_path (from fvSchemes or custom path (str)): fvSchemes template path
fvSolution_path (from fvSolution or custom path (str)): fvSolution template path
residual (float): Residual control, e.g. 1e-5
insidePoint (Point3d): A reference point inside the mesh/room
internalFields (from internalFields): Carbonfly internalFields
run (bool): When True, create Carbonfly case

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CreateCFGeometry

Create Carbonfly geometry

Inputs	Outputs
name (str): Region/solid name for STL & regions{}	log (str): Log
geometry (GeometryBase): Single surface/face/brep or a collection	CF_geo: Carbonfly Geometry
boundary (from 02:Boundary): Carbonfly boundary
refine_levels (Interval): Refine levels for meshing: (min, max) or as a single float number

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Carbonfly Info

Information about Carbonfly

Inputs	Outputs
	version (str): Carbonfly version
	homepage (str): Homepage URL
	license (str): Carbonfly license

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02:Boundary

Body

Manikin body boundary

Inputs	Outputs
temperature (float): Skin temperature in K	boundary: Carbonfly Body boundary

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Dynamic Respiration

Dynamic respiration boundary condition for transient simulation

Inputs	Outputs
freq (float): breaths per minute, default: 12 breaths per minute (0.2 Hz)	boundary: Carbonfly Dynamic Respiration boundary
breathing_flow_rate (float): Average breathing flow rate in L/min, default: 7.2 L/min
temperature (float): Core temperature in K
CO2 (float): Exhaled $\rm CO_2$ as volume fraction (e.g., 0.000450 for 450 ppm)

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Dynamic Window

Dynamic pressure-driven window boundary condition for transient simulation with natural ventilation

Inputs	Outputs
velocity (Vector3d): Velocity (m/s) as a vector, e.g. (0, 0, -1), for initialization. Not enforced during solve (dynamic, pressure-driven)	boundary: Carbonfly Dynamic Window boundary
temperature (float): Outdoor temperature in K
CO2 (float): Outdoor $\rm CO_2$ concentration as volume fraction (e.g., 0.000450 for 450 ppm)
pressure (float): Outdoor air pressure in Pa

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InletVelocity

Static air inlet boundary, e.g. for mechanical ventilation

Inputs	Outputs
velocity (Vector3d): Inlet velocity (m/s) as a vector, e.g. (0, 0, -1)	boundary: Carbonfly InletVelocity boundary
temperature (float): Inlet temperature in K (e.g. 293.15)
CO2 (float): Inlet CO₂ as volume fraction (e.g., 0.000450 for 450 ppm)

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internalFields

Initial internal field definitions for the simulation domain

Inputs	Outputs
U_internal (Vector3d): internalFields for velocity (U) in m/s	log (str): Log
T_internal (float): internalFields for air temperature in K	internalFields: Carbonfly internalFields
CO2_internal (float): internalFields for $\rm CO_2$ concentration, as volume fraction (e.g., 0.000450 for 450 ppm)
p_internal (float): internalFields for pressure in Pa

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Outlet

Outlet boundary (zeroGradient)

Inputs	Outputs
	boundary: Carbonfly Outlet boundary

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RecircReturn

Recirculated return from the room. Pair with RecircSupply.

Inputs	Outputs
velocity (Vector3d): Return velocity (m/s) as a vector, e.g. (0, 0, -1)	boundary: Carbonfly RecircReturn boundary

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RecircSupply

Recirculated supply to the room. $\rm CO_2$ can mirror the Return average to model no-fresh-air recirculation. Pair with RecircReturn.

Inputs	Outputs
velocity (Vector3d): Supply velocity (m/s) as a vector, e.g. (0, 0, -1)	boundary: Carbonfly RecircSupply boundary
temperature (float): Supply temperature in K (e.g. 293.15)
return_name (str): Region/solid name of Recirculation Return

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Wall

Fixed isothermal solid wall boundary condition

Inputs	Outputs
temperature (float): Surface temperature in K (e.g. 293.15)	boundary: Carbonfly Wall boundary

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03:Recipe

controlDict

OpenFOAM controlDict settings

Inputs	Outputs
mode (str): Simulation mode: transient or steady-state (or steady / steadystate)	log (str): Log
writeInterval (float): Results write interval, in seconds (transient) / iterations (steady-state)	controlDict: Carbonfly controlDict
endTime (float): Simulation end time, in seconds (transient) / iterations (steady-state)

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fvSchemes

OpenFOAM fvSchemes settings

Inputs	Outputs
mode (str): Simulation mode: transient or steady-state (or steady / steadystate)	fvSchemes_path (str): fvSchemes template path

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fvSolution

OpenFOAM fvSolution settings

Inputs	Outputs
mode (str): Simulation mode: transient or steady-state (or steady / steadystate)	fvSolution_path (str): fvSolution template path

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Residual Control List

A preset list for residual control

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04:Solution

blockMesh

Run blockMesh, creates a simple background mesh from block definitions

Inputs	Outputs
case_path (from createCFCase or custom path (str)): Carbonfly case path	log (str): Log
distro (str): Name of the WSL distribution/profile to run the command in (e.g., "Ubuntu-20.04"); leave blank to use your default WSL
foam_bashrc (str): Path to the OpenFOAM bashrc file to source before running the command (e.g., “/opt/openfoam10/etc/bashrc”); leave blank to skip sourcing/use the current environment
run (bool): When True, run blockMesh

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runFoam

Run OpenFOAM solver (buoyantReactingFoam) for simulation

Inputs	Outputs
case_path (from createCFCase or custom path (str)): Carbonfly case path	log (str): Log
distro (str): Name of the WSL distribution/profile to run the command in (e.g., "Ubuntu-20.04"); leave blank to use your default WSL
foam_bashrc (str): Path to the OpenFOAM bashrc file to source before running the command (e.g., “/opt/openfoam10/etc/bashrc”); leave blank to skip sourcing/use the current environment
run (bool): When True, run OpenFOAM solver

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snappyHexMesh

Run snappyHexMesh, generates a body-fitted mesh around geometry by refining and snapping cells.

Inputs	Outputs
case_path (from createCFCase or custom path (str)): Carbonfly case path	log (str): Log
distro (str): Name of the WSL distribution/profile to run the command in (e.g., "Ubuntu-20.04"); leave blank to use your default WSL
foam_bashrc (str): Path to the OpenFOAM bashrc file to source before running the command (e.g., “/opt/openfoam10/etc/bashrc”); leave blank to skip sourcing/use the current environment
run (bool): When True, run snappyHexMesh

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surfaceFeatures

Run surfaceFeatures, extracts sharp edges/features from surface geometry.

Inputs	Outputs
case_path (from createCFCase or custom path (str)): Carbonfly case path	log (str): Log
distro (str): Name of the WSL distribution/profile to run the command in (e.g., "Ubuntu-20.04"); leave blank to use your default WSL
foam_bashrc (str): Path to the OpenFOAM bashrc file to source before running the command (e.g., “/opt/openfoam10/etc/bashrc”); leave blank to skip sourcing/use the current environment
includedAngleDeg (float): includedAngleDeg for surfaceFeatures, default: 150
run (bool): When True, run surfaceFeatures

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checkMesh

Run checkMesh, checks mesh quality (non-orthogonality, skewness, aspect ratio, etc.).

Inputs	Outputs
case_path (from createCFCase or custom path (str)): Carbonfly case path	log (str): Log
distro (str): Name of the WSL distribution/profile to run the command in (e.g., "Ubuntu-20.04"); leave blank to use your default WSL
foam_bashrc (str): Path to the OpenFOAM bashrc file to source before running the command (e.g., “/opt/openfoam10/etc/bashrc”); leave blank to skip sourcing/use the current environment
run (bool): When True, run checkMesh

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foamMonitor

Run foamMonitor, live monitoring tool to track residuals during simulation.

Inputs	Outputs
case_path (from createCFCase or custom path (str)): Carbonfly case path	log (str): Log
distro (str): Name of the WSL distribution/profile to run the command in (e.g., "Ubuntu-20.04"); leave blank to use your default WSL
foam_bashrc (str): Path to the OpenFOAM bashrc file to source before running the command (e.g., “/opt/openfoam10/etc/bashrc”); leave blank to skip sourcing/use the current environment
start_time (float): Monitor residuals from time/iteration {start_time}, default: 0
run (bool): When True, run foamMonitor

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05:Util

Air Exchange Rate (Maas)

Air exchange rate in m3/h using Maas' formula:

$\rm \dot{Q} = 3600 \cdot \frac{1}{2} \cdot A_{eff} \cdot \sqrt{(C_1 \cdot u^2 + C_2 \cdot H \cdot \Delta \vartheta + C_3)}$

Where:

1. $\rm A_{eff}$: the effective opening area in $\rm m^2$
2. $\rm u$: the outdoor wind speed in m/s
3. $\rm H$: the height of the window sash in m
4. $\rm C_1$: coefficient, $\rm = 0.0056$
5. $\rm C_2$: coefficient, $\rm = 0.0037$
6. $\rm C_3$: coefficient, $\rm = 0.012$
7. $\rm \Delta \vartheta$: the temperature difference between the inside and outside in K

Note: This approximation has only been validated under conditions in which the outdoor temperature is lower than the indoor temperature. Its accuracy under the opposite condition remains unverified.

Source: Anton Maas. Experimental quantification of air exchange during window ventilation. PhD thesis, University of Kassel, Kassel, 1995. URL: https://www.uni-kassel.de/fb6/bpy/de/forschung/abgeschlprojekte/pdfs/maas_diss.pdf

Inputs	Outputs
A_eff (float): the effective opening area in $\rm m^2$	Qdot (float): Air exchange rate in m3/h
u (float): the outdoor wind speed in m/s
H (float): the height of the window sash in m
delta_theta (float): the temperature difference between the inside and outside in K

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BSA (Du Bois)

Calculate Body Surface Area (BSA) using Du Bois' Formula:

$\rm BSA (m^2) = 0.007184 \cdot Height (cm)^{0.725} \cdot Weight (kg)^{0.425}$

Source: D. Du Bois, CLINICAL CALORIMETRY: TENTH PAPER A FORMULA TO ESTIMATE THE APPROXIMATE SURFACE AREA IF HEIGHT AND WEIGHT BE KNOWN, Archives of Internal Medicine XVII (6_2) (1916) 863. doi:10.1001/archinte.1916.00080130010002

Inputs	Outputs
height (float): Height in cm	BSA (float): Body Surface Area in $\rm m^2$
weight (float): Weight in kg

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CO2 generation rate

Get $\rm CO_2$ generation rate (L/s) based on mean body mass in each age group.

Source: Persily and De Jonge, Carbon dioxide generation rates for building occupants, Indoor Air 27 (5) (2017) 868–879. doi:10.1111/ina.12383

Inputs	Outputs
age (float): Age, between 0-100	mass (float): mean body mass (kg)
met (float): Level of physical activity (met), met must be one of [1.0, 1.2, 1.4, 1.6, 2.0, 3.0, 4.0]	BMR (float): Basal Metabolic Rate (MJ/day)
gender (str): "male", "female", None (default returns average for both genders)	CO2_Ls (float): $\rm CO_2$ generation rate (L/s)
breathing_flow_rate (float): Average breathing flow rate in L/min, default: 7.2 L/min	CO2_ppm (float): Exhaled $\rm CO_2$ concentration (ppm)
	CO2 (float): Exhaled $\rm CO_2$ concentration as volume fraction (e.g., 0.000450 for 450 ppm)

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Gagge two-node model

Gagge Two-node model of human temperature regulation Gagge et al. (1986).

Source: Gagge, A.P., Fobelets, A.P., and Berglund, L.G., 1986. A standard predictive Index of human reponse to thermal enviroment. Am. Soc. Heating, Refrig. Air-Conditioning Eng. 709–731.

Inputs	Outputs
tdb (float): Dry bulb air temperature in °C	e_skin (float): Total rate of evaporative heat loss from skin in W/m2. Equal to e_rsw + e_diff
tr *(float): Mean radiant temperature in °C	e_rsw (float): Rate of evaporative heat loss from sweat evaporation in W/m2
v (float): Air speed in m/s	e_max (float): Maximum rate of evaporative heat loss from skin in W/m2
rh (float): Relative humidity in %	q_sensible (float): Sensible heat loss from skin in W/m2
met (float): Metabolic rate in met	q_skin (float): Total rate of heat loss from skin in W/m2. Equal to q_sensible + e_skin
clo (float): Clothing insulation in clo	q_res (float): Total rate of heat loss through respiration in W/m2
wme (float): External work in met. Defaults to 0	t_core (float): Core temperature in °C
BSA (float): Body surface area, default value 1.8258 $\rm m^2$	t_skin (float): Skin temperature in °C
p_atm (float): Atmospheric pressure in Pa, default value 101325 Pa	m_bl (float): Skin blood flow in kg/h/m2
position (str): Select either "sitting" or "standing". Defaults to "standing"	m_rsw (float): Rate at which regulatory sweat is generated in mL/h/m2
max_skin_blood_flow (float): Maximum blood flow from the core to the skin in kg/h/m2. Defaults to 90	w (float): Skin wettedness, adimensional. Ranges from 0 to 1
max_sweating (float): Maximum rate at which regulatory sweat is generated in kg/h/m2. Defaults to 500	w_max (float): Skin wettedness (w) practical upper limit, adimensional. Ranges from 0 to 1
w_max (float): Maximum skin wettedness (w) adimensional. Ranges from 0 and 1. Defaults to False	SET (float): Standard Effective Temperature (SET)
	ET (float): New Effective Temperature (ET)
	pmv_gagge (float): Gagge's version of Fanger's Predicted Mean Vote (PMV)
	pmv_set (float): PMV SET
	disc (float): Thermal discomfort (DISC). DISC is described numerically as: comfortable and pleasant (0), slightly uncomfortable but acceptable (1), uncomfortable and unpleasant (2), very uncomfortable (3), limited tolerance (4), and intolerable (5). The range of each category is ± 0.5 numerically
	t_sens (float): Predicted Thermal Sensation

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Gagge two-node model (sleep)

Adaption of the Gagge two-node model for sleep thermal environment, by Yan et al.

Source: Yan, S., Xiong, J., Kim, J. & de Dear, R. (2022). Adapting the two-node model to evaluate sleeping thermal environments. Building and Environment. 222, 109417. DOI: doi.org/10.1016/j.buildenv.2022.109417

Inputs	Outputs
tdb (float): Dry bulb air temperature in °C	e_skin (float): Total rate of evaporative heat loss from skin in W/m2. Equal to e_rsw + e_diff
tr *(float): Mean radiant temperature in °C	t_core (float): Core temperature in °C
v (float): Air speed in m/s	t_skin (float): Skin temperature in °C
rh (float): Relative humidity in %	skin_blood_flow (float): Skin blood flow in kg/h/m2
clo (float): Clothing insulation in clo	w (float): Skin wettedness, adimensional. Ranges from 0 to 1
thickness_quilt (float): Thickness of the quilt in cm	SET (float): Standard Effective Temperature (SET)
wme (float): External work in met. Defaults to 0	disc (float): Thermal discomfort (DISC). DISC is described numerically as: comfortable and pleasant (0), slightly uncomfortable but acceptable (1), uncomfortable and unpleasant (2), very uncomfortable (3), limited tolerance (4), and intolerable (5). The range of each category is ± 0.5 numerically
p_atm (float): Atmospheric pressure in Pa, default value 101325 Pa	t_sens (float): Predicted Thermal Sensation
height (float): Height of the person in cm. Defaults to 171	met_shivering (float): Metabolic rate due to shivering in W/m2
weight (float): Weight of the person in kg. Defaults to 70	alfa (float): Dynamic fraction of total body mass assigned to the skin node (dimensionless)
c_sw (float): Driving coefficient for regulatory sweating. Defaults to 170
c_dil (float): Driving coefficient for vasodilation. Defaults to 120
c_str (float): Driving coefficient for vasoconstriction. Defaults to 0.5
temp_skin_neutral (float): Skin temperature at neutral conditions in °C. Defaults to 33.7
temp_core_neutral (float): Core temperature at neutral conditions in °C. Defaults to 36.8
e_skin (float): Total evaporative heat loss in W. Defaults to 0.094
alfa (float): Dynamic fraction of total body mass assigned to the skin node. Defaults to 0.1
skin_blood_flow (float): Skin-blood-flow rate per unit surface area in kg/h/m2. Defaults to 6.3
met_shivering (float): Metabolic rate due to shivering in met. Defaults to 0

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Surface Wind Pressure

Computes peak and surface wind pressure for vertical walls of rectangular plan buildings (h/d <=5 and height <= 200m)

Source: DIN EN 1991-1-4:2010-12. Eurocode 1: Actions on structures - Part 1-4: General actions - Wind actions; German version EN 1991-1-4:2005 + A1:2010 + AC:2010. DOI: https://dx.doi.org/10.31030/1625598

Notes: For other building types, please see DIN EN 1991-1-4:2010-12.

Inputs	Outputs
vb0 (float): Fundamental value of the basic wind velocity v_b,0 [m/s] (from National Annex map, 10 m, terrain II, 50 yr)	we (float): Wind pressure on the external surface [Pa]
z (float): Height above ground level of the measured/evaluated point [m]	cpe (float): External pressure coefficients for vertical walls of rectangular plan buildings [-]
h (float): Height of the building [m]	qp (float): Peak velocity pressure [Pa]
d (float): Length of the building [m]	vm (float): Mean wind speed [m/s]
window_size (float): Window size in [m^2]	Iv (float): Turbulence intensity
zone (str): External pressure zones*, A/B/C on side/roof edges along the flow, D windward face, and E leeward face	cr (float): Roughness factor
terrain (int): Terrain type, 0/1/2/3/4, default: 4, corresponding to Type 0/I/II/III/IV**	vb (float): Basic wind velocity [m/s]
c_dir (float): Directional factor, for various wind directions may be found in the National Annex. The recommended value is 1.0
c_season (float): Season factor, may be given in the National Annex. The recommended value is 1.0
c0 (float): Orography factor, taken as 1.0 unless otherwise specified. Note: Information on c0 may be given in the National Annex. If the orography is accounted for in the basic wind velocity, the recommended value is 1.0
rho (float): Air density in kg/m3. The default value is 1.25 kg/m3
k_i (float): Turbulence factor. The value of k_i may be given in the National Annex. The recommended value for k_i is 1.0

*External pressure zones:

Top view:
               <- - - d (length)  - ->
               -----------------------     ^
               |                     |     |
    wind --> D |                     | E   b (width)
               |                     |     |
               -----------------------     -
    D = windward face (positive pressure / stagnation)
    E = leeward face (negative pressure / wake suction)

Side view:
               <- - - d (length)  - ->
               -----------------------     ^
               |   |         |       |     |
    wind -->   | A |    B    |   C   |     | h (height)
               |___|_________|_______|     _
               <- - - e - - ->
                   <- 4/5 e ->
               Where: e = b or 2h, whichever is smaller
    A: leading corner band (strongest suction)
    B: intermediate edge band
    C: outer side/roof band

**Terrain type:

• 0: Sea, coastal area exposed to the open sea.
• 1: Lakes or area with negligible vegetation and without obstacles.
• 2: Area with low vegetation such as grass and isolated obstacles (trees, buildings) with separations of at least 20 obstacle heights.
• 3: Area with regular cover of vegetation or buildings or with isolated obstacles with separations of maximum 20 obstacle heights (such as villages, suburban terrain, permanent forest).
• 4: Area in which at least 15 % of the surface is covered with buildings and their average height exceeds 15 m.

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Manikin LOD 0

Create a manikin with Level of Detail of 0.

Inputs	Outputs
Base Point (Point3d): Location base/reference point of the manikin model	Body Surface Area (float): Body Surface Area in $\rm m^2$
unit (str): "mm" (default), "cm", "m", unit setting in Rhino	Body (Surface): Collection of manikin body surfaces
width (float): Width of the manikin model	Mouth (Surface): Collection of manikin mouth surfaces
height (float): Height of the manikin model	Breathing_U (float): Breathing velocity (for simplified constant exhalation) in m/s
StV_height (float): Stomion (mouth) to vertex height, default: 17 cm *
activity (str): The level of activity: "light" (default) / "medium" / "heavy", affects the size of the mouth opening
breathing_flow_rate (float): Average breathing flow rate in L/min, default: 7.2 L/min
mouth_scaling (float): Mouth opening scaling factor: 1 - 5, default: 4 **
angle (float): Rotation angle in radians of the manikin model

*For reference: 1) Adult: ~16-17 cm (females) / ~17-18 cm (males); 2) Children (6–12 years): ~12-15 cm

**A larger scale factor increases the mouth's opening area, reducing velocity while maintaining flow rate, thereby simplifying the mesh.

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Met List

A preset list for Metabolic rate in met.

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06:Post-processing

internalProbes

Create an OpenFOAM system/internalProbes dictionary for post-processing.

Inputs	Outputs
case_path (str): Carbonfly case path	log (str): Log
points (Point3d): Probe point locations to be written into system/internalProbes. Accepts a single point or a list of points
unit (str): (Optional) Unit of the input points. Supported values: "m", "cm", or "mm" (default). The component automatically converts the points to meters before writing them to the OpenFOAM dictionary
fields (str): Name or list of field names to be sampled at the given points (for example: CO2, T, U, p). Field names must match those available in the OpenFOAM case
run (bool): When True, write internalProbes

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postProcess

Run OpenFOAM post-processing for internalProbes.

Inputs	Outputs
case_path (str): Carbonfly case path	log (str): Log
distro (str): Name of the WSL distribution/profile to run the command in (e.g., "Ubuntu-20.04"); leave blank to use your default WSL
foam_bashrc (str): Path to the OpenFOAM bashrc file to source before running the command (e.g., “/opt/openfoam10/etc/bashrc”); leave blank to skip sourcing/use the current environment
time_selector (str): (Optional) Controls which time(s) to process*
run (bool): When True, run postProcess

*Examples for time_selector:

• leave it empty: process all available times.
• (string) "latestTime" or "latest" or "last": run with -latestTime.
• (int) e.g. "100": run with -time 100.
• (int:int) e.g. "0:100": run with -time 0:100.

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Read Results

Read sampled field values from postProcessing/internalProbes//points.xy and convert probe coordinates back to the current Rhino unit. Use this after you have already:

1. written internalProbes, and
2. run postProcess.

Inputs	Outputs
case_path (str): Carbonfly case path	time_dir (float): Name of the time directory that was actually read (e.g. 2000)
which (str): (Optional) which result to read*	points (Vector3d): Probe coordinates converted to the Rhino unit
field (str): Field name to extract (e.g. CO2, T, U, p)	values (float or Vector3d): Field values at these probes (list of numbers, or list of Vector3d for U)
unit (str): Unit for output probe coordinates (m, cm, or mm; default mm)

*Examples for which:

1. "latest" / "last": read the newest time dir (default)
2. (int) for example:
   1. "0": read the first time dir (smallest time)
   2. "2": read the 3rd time dir
   3. "-1": read the last time dir

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CO2-based IAQ

Evaluate Indoor Air Quality (IAQ) from CO2 concentration, based on different international/national standards.

Warnings:

CO2 is only suitable for assessing IAQ as an indirect proxy indicator of ventilation rate. The assessment should be made aware of the following limitations:

1. CO2 below the threshold does not ensure an acceptable overall IAQ, but an excessively high CO2 may indicate that the room is not well ventilated, e.g. the ventilation system is not functioning correctly or the windows are closed for a long period of time.
2. The direct impact of CO2 on health, well-being, and performance is still controversial. At the same time CO2 should not be used directly as a direct indicator of the risk of disease transmission, but should only be considered as an indirect indicator of ventilation rates.
3. CO2 measurements are greatly influenced by the accuracy of the sensor, its installation location and calibration method.

Therefore, ASHRAE does not have a CO2-based IAQ index, see:

Persily A. 2020. Quit Blaming ASHRAE Standard 62.1 for 1000 ppm CO2, Indoor Air 2020 - The 16th Conference of the Internatinal Society of Indoor Air Quality & Climate.

Inputs	Outputs
CO2_indoor (float or list): Indoor CO2 concentration (ppm)	report (str): IAQ report
CO2_outdoor (float or list): Outdoor CO2 concentration (ppm); if empty, 400 ppm is used	index (float): The IAQ Index/Category. For description please see IAQ report
standard (str): CO2-based IAQ assessment standard to apply*

*Standards:

• European standard CEN/EN 16798-1 = "EN"
• Japanese law for environmental health in buildings (LEHB) = "LEHB"
• Singapore standard SS 554:2016 = "SS"
• Hong Kong Environmental Protection Department = "HK"
• German environmental protection agency (Umweltbundesamt) = "UBA"
• Department of Occupational Safety and Health (DOSH) Malaysia = "DOSH"
• Brazilian standard ABNT NBR 16401-3:2008 and NBR 17037:2023 = "NBR"

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Carbonfly IAQ Standards

A preset list of CO2-based IAQ standards.

Warnings:

CO2 is only suitable for assessing IAQ as an indirect proxy indicator of ventilation rate. The assessment should be made aware of the following limitations:

1. CO2 below the threshold does not ensure an acceptable overall IAQ, but an excessively high CO2 may indicate that the room is not well ventilated, e.g. the ventilation system is not functioning correctly or the windows are closed for a long period of time.
2. The direct impact of CO2 on health, well-being, and performance is still controversial. At the same time CO2 should not be used directly as a direct indicator of the risk of disease transmission, but should only be considered as an indirect indicator of ventilation rates.
3. CO2 measurements are greatly influenced by the accuracy of the sensor, its installation location and calibration method.

Therefore, ASHRAE does not have a CO2-based IAQ index, see:

Persily A. 2020. Quit Blaming ASHRAE Standard 62.1 for 1000 ppm CO2, Indoor Air 2020 - The 16th Conference of the Internatinal Society of Indoor Air Quality & Climate.

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