1. Mikael Salonvaara, Andreas Nicolai, Hui Li, Jensen Zhang
Overview of CHAMP – Combined Heat Air Moisture and Pollutant Transport Simulation Model
Mikael Salonvaara, Andreas Nicolai, Hui Li, Jensen Zhang
and John Grunewald

2. Modeling objectives Develop
An integrated computer simulation environment for assessing the Combined Heat, Air, Moisture and Pollutants Transport in a whole building system (CHAMP)
Mathematical models and computer simulation tools for the assessment of the long-term energy, indoor environmental quality (IEQ), and durability performance of building envelope systems
Fast CHAMP simulation models for real-time predictive control of building environmental systems
Benchmark and validate the simulation models by conducting small and full-scale laboratory experiments, and field tests
Apply models to analyze the effects of IAQ control options and building envelope design on individual exposure, energy efficiency and durability

3. Envelope Model Model development Model implementation
In-material diffusion and sorption; coupled moisture, VOCs
Effects of leakage (air) flows
Boundary conditions
Model implementation
2-D heat, air, moisture and VOC program in C++
Development of a user interface and ‘helper tools’
Shared database development
Coupling with other models
Model benchmarking
Parametric study and sensitivity analysis (trend and uncertainties)
Determination of transport properties of building materials
Comparison with full-scale experimental data and existing models
Comparison with field performance

4. CHAMP Building Envelope Model Overview
Heat, Air, Moisture and Pollutant (VOC) transport and sorption
Multilayered assemblies (walls, roofs, components)
C++, 2D (will be extended to 3D)

5. CHAMP Building Envelope model
Simulation of one and two-dimensional multilayered structures, components and materials…
Walls (exterior, interior)
Furniture, …
exposed to natural climates
Indoor climate
Temperature, humidity, pressure, VOC concentrations
Outdoor climate
Temperature, humidity, pressure, wind speed and direction, solar radiation, counter radiation (sky, clouds, surfaces), rain
User defined conditions

6. IAQ & Energy Performance of Building Systems
long wave radiation
solar radiation
temperature
(Extinction: Adsorption, Dispersion, Reflection)
heated cellar
garage
cooking, laundry
Emissions
warm roof
cold roof
humidity
wind
rain
air pressure
cloud covering
diffusion
transmission
convection
air tightness
air leakage
(rot, mold)
Coupled
Heat
thermal bridge
(surface condensation, mold)
Air
temperature
relative humidity
transmission
ventilation
convection
air exchange
Moisture
air leakage
Pollutant
Simulation
thermal bridge
imperfect sealing
(salt efflorescence)
capillary flow
diffusion
ground water
ground
water

7. Model equations Equations are included for Material properties
Heat conduction
Air transport in porous materials and cavities (carrying heat, vapor, VOC)
Water vapor diffusion, liquid transport
VOC diffusion
Material properties
Sorption
Transport properties
Liquid phase
Vapor phase

8. Equations - Diffusion
Water vapor diffusion

9. Model Parameters/Material Characterization
Moisture storage property (sorption, water retention)
VOC sorption similarly but at low concentrations

10. VOC sorption
VOC sorption is commonly presented with partition coefficients i.e.
Cm = Kma  Ca
Kma is strongly dependent on temperature (e.g. doubles every 10K)
Water vapor sorption
w = f(RH = pv/pv,sat)
Much less dependent on temp.
Usually only one curve used
New concept for VOCs
Cm = f(RC) = Kma  Ca,sat  RC
RC = Ca/Ca,sat
Evidence in literature data
Sorption of benzene in soil
Henry’s law constant at 50C = 10x at 14C
…etc.

11. User Interface – Input and Output Processing
User interface creates an ascii data file

12. Tool - Material Property Inspector
Visualize material properties and check anomalies

13. Post-Processing
User can select outputs (points, fields, flows) and intervals
Internal chart engine and conversion tool to Tecplot

14. Example: Investigation of 2 VOC Sorption Models
Cm = Kma  Ca (KMA model, no temp. effects)
Cm = f(RC) = Kma  Ca,sat  RC (RC model)
Simulation of a light-weight wood frame wall exposed to exterior and interior climate with air infiltration through the wall
Air infiltration rate m3/m2h (small)
Indoor conditions constant 20C, 50% relative humidity
Weather: Syracuse – Comparison of months
January
July
Assumed initial conditions
High concentration of toluene in OSB

15. Light-Weight Wood-Frame Wall
OSB
Fiberglass insulation
Gypsum board
Air leakage from top outside to bottom indoor side
How much VOC is transported indoors by diffusion and airleakage?
Air leakage through wall is shown with arrows.
Indoor air is on the right.
Outdoor air is on the left.

16. Total VOC Flux to Indoor Climate

17. Full-Scale Experimental Validation
Air flow characterization
VOC emissions with airflow through wall assembly

18. Test Wall with Instrumentation
Supply
Top wood
Supply S7
Roof space
Return
OSB S5 S2 S4
Gypsum board
RH28
RH29
VOC injection port
Facing of insulation
Insulation S1 S3
VOC sampling port S6
Return
Bottom wood
Floor space
Pressure sensor
T/RH sensor
Climate chamber
(Outdoor)
Test wall
IEQ chamber
(Indoor)

19. VOC Emissions to IEQ Chamber
+10 Pa pressure difference
Emission factor (g/m2h)

20. What is Next? Model availability Develop user group
First release version of CHAMP, August 2006
Available to everyone interested
Develop user group
Feedback
Collaborative development possibilities
Shared database development
Material properties
Experimental data
Analyzed properties
Applications to specific emission problems
Formaldehyde from office furniture and composite wood products
Moisture/mold control in critical building envelope structures
Outdoor to indoor pollutant transport