SimScale teams up with Smartlouvre Technology Ltd. to demonstrate how simulation technology can be used to evaluate the performance of MicroLouvre, a woven mesh of paper-thin bronze louvres. This product is used externally on windows and building facades to block and absorb heat, and control glare. As the only one of its kind on the market, MicroLouvre provides an option for low energy building designers that improves the performance of glazing while still allowing for daylight and natural ventilation. SimScale evaluated the performance of Microlouvre testing its structural properties against airflow, solar, and thermal data.

1. Dr. Naghman Khan, Darren Lynch (SimScale GmbH)
Andrew Cooper, Carter Gilbert (Smartlouvre Technology Ltd.)
Simulating MicroLouvre™
for Low Energy Building
Design

2. About SimScale
Who we are
● Founded in 2012
● Offices in Munich, Boston, and New York
● 80+ employees across 8+ time zones
● 150,000 users worldwide
● 250k simulation projects

3. About SimScale
What we do
We created the world’s first cloud-based
engineering simulation platform.
● Fluid dynamics (CFD)
● Solid mechanics (FEA)
● Thermodynamics
All accessible via a web browser.
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4. About Smartlouvre
Who we are
● Founded in 2015
● We are weavers of metal fabric
● On the only looms of their kind
● Shipped from the US in 2003
● Computerised for the 21st Century

5. About Smartlouvre
What we do
We work with architects, engineers, and developers
to apply our high performing MicroLouvre™ fabric
to their buildings.
● Fine metal mesh made of copper/bronze alloy
louvres
● Manufactured in the UK
● Used to control solar gains and glare whilst
allowing natural ventilation and daylight
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6. Table of Contents
1. MicroLouvre™
2. Simulating Airflow
3. Simulating Thermal Performance
4. Benefits of Using MicroLouvre™
5. Additional Resources

7. MicroLouvre™
Technical Presentation

8. MicroLouvre™ is constructed of paper thin bronze louvres,
woven into a metal fabric and used to enhance the
performance of any glazing or buildings’ facade. It is
commonly attached to external windows and acts as a solar
shading and glare control device.
MicroLouvre™ metal fabric has exceptional properties that
combine to deliver unrivalled performance in its field.
As well as blocking and absorbing heat, it controls glare. It is
lightweight and exceptionally strong, making it uniquely
versatile. Most importantly, it allows through daylight and
natural ventilation.
It has been used in limitless shapes, sizes, and colours for all
types of window coverings, lighting design, and exhibition
displays.
MicroLouvre
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9. Its corrosion resistant, non-combustible, and recyclable
copper alloys (bronze) make it a highly durable and long
lasting, environmentally friendly product.
The unique view through metal fabric is most
commonly fabricated into heat blocking and solar
shading screens, as well as privacy and security screens,
for fire & heat attenuation, burning ember protection,
and as an insect barrier.
The fabric is also utilised in the lighting industry to
mitigate glare and for directional light control, and in
ventilation systems to filter and control air flow.
MicroLouvre
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10. Property Data for Simulation
Open Area face on 67%
Microlouvre angle of louvres 17°
Open Area in-line with louvres 80%
Solar shading >40° 100%
Solar heat block >40° 100%
Solar factor >40° 0
Solar absorptance >40° 0.97
Solar reflectance >40° 0.03
Visual transmittance 51.50%
UV 30° at 68%, 50° at 100%
Privacy 100% >40°
Wind Loading 14.5 Kg/m2 at 60 mph wind
Material Copper alloy
Copper resistance 189 W/m K
Weight (nominal) 1.1 kg/m2
Fire rating
A1/A2-s1,d0 : BS EN
13501-1:2007 +A1:2009
Key Performance Characteristics
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11. Simulating Airflow
Technical Presentation

12. Objective :
● To determine the nominal discharge coefficient of
MicroLouvre.
● To assess the airflow around the louvre system to
understand where pressure loss occurs.
● To determine porosity factors which are generic for
any CFD tool.
Introduction
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13. Set Up & Run
a Simulation
Assess Results
Calculate Discharge
Coefficient
1
3-Part Workflow
1. Run an incompressible simulation in SimScale.
2. Use the pressure and velocity results to
understand how flow moves around your
product, and how it could be improved.
3. Use the pressure values before and after the
louvre to obtain discharge coefficient.
2
3
CFD Simulation Setup
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14. ● Large ‘patterned’ geometry can be tested
using only a small section.
● To do this, the geometry should be
symmetric in both planes, and continuous
(re-patterned test section should get the
original geometry).
CFD Simulation Setup
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15. 15
● A pressure drop across MicroLouvre was
observed to be about 40Pa at 10 m/s
● Using a section area of 220mm², an open
air ratio of 80% (in-line), and 67%
perpendicular to flow.
40Pa
0Pa
Highest pressure is at
stagnation point
Where ⍴ is density, qv is the flow
rate, Cd is the discharge coefficient,
and A is the free area.
Velocity and Pressure
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16. 16
● The speed and direction of the flow
can be looked at in detail around
each louvre.
● It shows clearly stagnation, high
velocity zones, separation points, and
the wake, all of these things increase
the overall pressure drop.
● A large pressure drop leads to large
discharge coefficients, which means
the amount of flow able to pass a
louvre under natural ventilation will
be reduced.
Stagnation
point
Flow separation
Wake
High velocity
Approximately 1.2mm
Airflow Characteristics
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17. Airflow Characteristics
Flow has a distinct upwards trend when exiting
MicroLouvre. This is an aerodynamic pattern that
might be important but not captured in thermal
modelling.
This pattern would be more important when CFD
modelling room cooling strategies.
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18. Using the pressure drops along the MicroLouvre,
a second order model was used to find the
Darcy-Forchheimer Coefficients.
In the local x axis (The local axis of the model in
the simulation, 0.956, 0.292, 0):
d=2.307e6
f=20.78
Y axis coefficients were assumed blocking, with a
coefficients 2 orders higher. In the local y axis
(These are used for directional changes to mimic
louvre angle, -0.292, 0.956, 0)
d=2.307e8
f=2078
The identical test cases were run with porous
media to validate the model.
Porous Media
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19. 19
CFD Simulated Pressure Drop
● Using the displayed equation and the
pressure differences from a CFD simulation.
● Calculated using a section area of 220mm²
and a open air ratio of 67%.
● Discharge coefficient increases with flow
speed due to turbulent effects becoming
greater.
● A nominal Cd 0.4 at 67% open area ratio has
been determined and will be used.

20. 20
MicroLouvre Air Flow Into a Room
Air flow entering a room through MicroLouvre. Observable is the angled inflow due to the
structure of the louvre. The louvre also acts to filter out gusts and draughts.

21. 21
1.5 mm wide
● Assuming 600W/m2 on the top
surface outside face of the
Microlouvre.
● Power applied as a volume
source to the copper louvre.
● Natural convection induces a
flow over the louvres and
upwards.
● This will give a small overall ΔT
to the flow.
● This buoyancy effect is more
pronounced in low wind
conditions.
‘Chimney Effect’

22. Simulating Thermal Performance
Technical Presentation

23. Multi-Storey Building Example
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24. 24
Multi Storey healthcare type building - third floor (South Zone)
● Base Case Model Setup:
○ London (Central)
○ Total floor area 3791 m2
○ Total external opening area (Doors and windows) 329.62 m2
○ Lat: 51.48°
○ Long: 0.45°
○ Alt: 24m
● Standard Constructions Compliant With Part L 2013:
○ Roof U 0.18 w/m2
.k
○ Ground floor U 0.22 w/m2
.k
○ External walls U 0.26 w/m2
.k
○ Internal walls U 1.1 w/m2
.k
○ External glazing (Argon filled double pane) U 1.6 w/m2
.k, G
0.3993, VLT 0.71
● Space conditioning case set at 22° indoor set point occupied hours
(24h with increase from 8 am - 7 pm)
● Gains 10 W/m2
Lighting, 5 m2
/ person (90W Sen, 60W Lat)
● With Natural Ventilation case
Multi-Storey Building Example

25. 25
Method 1 ‘Translucent shade’ and
properties (construction database, see
next slide)
Tip: Use the ‘measure distance’ button
to confirm the plane of the transparent
shade or MicroLouvre (Distance above
ground in the case of ground floor for
example) then draw in on plan view.
Simulation Setup for MicroLouvre

26. Method 1 Translucent shade and
properties (construction database)
Construction set as copper 1.5 mm
thick with thermal conductivity of 189
W/m.K.
Applied explicit angular dependent
solar and optical properties at 10°
increments.
Draw in physically using ‘ModelIT’ as
transparent shade.
26
Construction Database in IES VE, showing a ‘MicroLouvre Single Pane’
Simulation Setup for MicroLouvre

27. 27
IES Angular
dependency
Solar
Transmittance
Visual Light
Transmittance
(VLT)
0 0.678 0.682
10 0.591 0.592
20 0.444 0.449
30 0.315 0.315
40 0.13 0.133
50 0.001 0.001
>50 0.000 0.000
In the construction database in Apache, set up a
new Construction called MicroLouvre Single Pane
(Suggested name). Add a single layer of copper
using the ‘System Materials’ tab, picking ‘Metals’
as the material category. Change thickness to 1.5
mm and conductivity to 189 W/m.K.
NOTE: The same data is read by RadianceIES for
daylight simulation.
Simulation Setup for MicroLouvre

28. Benefits of Using MicroLouvre™
Technical Presentation

29. 29
Annual solar gain with and
without MicroLouvre.
Multi-Storey 3rd Floor results

30. External incident solar flux on
windows with and without
MicroLouvre.
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Multi-Storey 3rd Floor results

31. 31
Multi-Storey 3rd Floor results
Cooling plant sensible load with
and without MicroLouvre
installed.
Up to 50% reduction in energy
needed to cool a space.

32. 32
Setup of MicroLouvre in IES Macroflo
Modelling Natural Ventilation
Defining natural ventilation parameters:
With MicroLouvre modelled either as a ‘Louvre’
with 17.32% openable area and discharge
coefficient of 0.4.
This gives an ‘equivalent orifice area’ of 11.174 as
% of gross. This is the key value which needs to be
managed and we arrive at this using an easy to
remember ‘rule of thumb’; the MicroLouvre
reduces airflow by ⅓ so the equivalent orifice area
of your default windows needs to be adjusted by
the same amount.
Default window can also be adjusted.

33. 33
Setup of MicroLouvre in IES Macroflo
Modelling Natural Ventilation

34. Daylight
Technical Presentation

35. Model settings using Radiance IES
3D model with and without MicroLouvre
Daylight
Model room with a set of windows
with and without MicroLouvre
installed. Default window is as before
and MicroLouvre settings are showing
in image.
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36. RadianceIES simulation of default window (left) and
with MicroLouvre installed (right)
RadianceIES simulation showing daylight lux
values with and without a ML
Daylight for Standard CIE Overcast Sky in Sep
Using a CIE Overcast sky on Sep 21st (Standard design day)
we can see with an additional MicroLouvre layer on top of a
double glazed window (0.71 Tv) enough daylight is still
available.
Important to note what daylight factor, internal illuminance
or other criteria are needed when considering
MicroLouvre.
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37. Compliance
Technical Presentation

38. 1. BREEAM international rating system under the Health & Wellbeing section:
● HEA4 Credit for thermal comfort analysis using a simulation tool to demonstrate methods to control and
reduce overheating risk using TM59/49 guidelines by modelling MicroLouvre
● ENE1 Energy Credit for reducing cooling demand leading to lower electricity use and carbon emissions
● WELL/BREEAM aligned
2. GLA Overheating criteria to reduce high risk of solar gains and internal thermal comfort issues on glass buildings
3. LEED EA (Energy) credit using strategies to reduce demand, harvest free energy, increase efficiency
4. Indoor Environmental Quality (EQ):
a. Ventilation effectiveness (Natural Ventilation)
b. Thermal comfort (With Natural Ventilation)
c. Daylight & Views
Credits for Energy Rating Systems - BREEAM/WELL
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39. 1. Case Study https://www.simscale.com/customers/smartlouvre-technology-ltd/
2. Smartlouvre Technology Ltd https://www.smartlouvre.com/
3. Microlouvre™ resources https://www.smartlouvre.com/downloads
4. Getting started with CFD https://www.simscale.com/signup/
Additional Resources
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