Deliverable 5.1 Report on Available Products and Passive

Transcrição

Deliverable 5.1
Report on Available Products
and Passive Cooling
Solutions
Final Version
Report prepared under the project Transforming the market from “cooling” to “sustainable
summer comfort”, supported by the European Commission by the Grant Agreement
EIE/07/070/SI2.466264 Keep Cool II.
Project management: Barbara Droeschel
Work package leader (WP5): Carlos Laia and Mathieu Richard
Authors:
PART A:
and
PART B: Martin Vukits, Dagmar Jähnig
The sole responsibility for the content of this report lies with the authors. It does not
represent the opinion of the European Communities. The European Commission is not
responsible for any use that may be made of the information contained therein.
INDEX
PART A – Product Sheets for Sustainable Summer Confort – SOLAR SHADING
1.
2.
3.
4.
5.
6.
7.
8.
9.
Summary Overview
Light-Directing Blinds
External Venetian Blinds
Roller Shutters
Roller Blinds and Awnings
All Indoor Products (blinds, fabrics, curtains, foils)
Horizontal Solar Fins, Louvers and Balconies
Vertical Solar Fins and Louvers
Sun Protection Glass and Sun Protection Foils
PART B – Report on Passive Cooling Solutions
1. Night Ventilation
2. Burglary and Weather Protection for Free Ventilation
3. Plaster and Plasterboard Integrated with Phase-Change-Material
4. Air-Ground-Heat-Exchanger
5. Decentral Air Conditioning Appliance Integrated with PCM
6. Direct Cooling with Ground Energy Source
7. Water Basin, -wall and -fountain
8. Indoor Plants
9. Daylight Illumination
10. Fans
PART A
Product sheets for
sustainable summer comfort
SOLAR SHADING
Summary overview
Performance data of the various shading systems differ greatly. The table below provides a summary of the functions
and features listed in the product factsheets by way of comparison. Each shading variant thus has its own characteristic prof le.
Key
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Maximum achievable energy transmission for use of solar energy / passive heating (based on the g value of the respective glazing)
Maximum achievable energy transmission for passive cooling purposes (based on the g value of the respective glazing)
Introduction of light through the shading (basic value is respectively the light transmission of the glazing TL)
Variability of a shading - Adaptation to changed energy flow during heating/cooling period (the higher the value, the more flexible)
Selectivity number (light transmission TL to total energy transmission value gtotal, values above 5 are extremely good)
Heat loss through glazing can be reduced by certain shading systems
Effects on the cooling requirement of active cooling systems as a result of passive cooling / sun protection
Effects on the heating energy requirement during the day as a result of utilisation of solar energy (passive heating)
Effects on the heating requirement at night as a result of shading systems
Effects on the thermal comfort, e.g. overheating, transmission of cold
Effects on the visual comfort, e.g. protection against direct glaring, light density restriction, daylight regulation
Effects on psychological factors, in particular view to the outside, contact to the outside world when shading is activated
Effect on the electricity requirement for artificial lighting as a result of shading systems
Preferred installation position / orientation of the shading
Wind speed up to that a shading is functional
Average expected serviceable life of a product
Dy n a m i c S o l a r S h ad in g With D aylight Transport
(i n fro n t o f / i n b etw ee n /b e h in d g lazing)
LI G H T- D I R E C T IN G B L IN D S
PRODUCT DESCRIPTION
Light-directing blinds are characterised by their highly ref ective slat curtain. In order to provide the best possible sun protection, the slats are adjusted depending
on the position of the sun while diffuse (low-energy) light from the sky is simultaneously transported via the ref ectors (slats) into the room.
The energy balance of such systems is optimal, they achieve the best sun protection values, reduce the requirement for artif cial illumination by up to 80 %, and
also ensure solar gains for passive room heating.
Light-directing blinds are highly eff cient passive cooling systems that, as
they are adjustable and retractable, can be adapted very well to the outside
conditions(direct and diffuse radiation).
In the heating period, signif cant free, natural solar gains can be achieved as the
shading system can be retracted to allow the solar energy into the building - passive heating.
Light-directing blinds require motorised drives in combination with a user-oriented, automatic control.
Motorised light-directing blinds, in connection with motorised drives, a well designed control system and openable windows ensure that no or only little cooling
energy is required during the day, while ensuring eff cient cooling at night.
PRODUCT WILL PROVIDE
• Sun protection /passive cooling - Protection against overheating and
greenhouse effect. Signif cant reduction of the heat transmission from outside;
the load on the active cooling system can be minimised and/or active cooling is
not necessary at all.
• Use of free, renewable solar heat gains / passive heating - The curtain can
be retracted and/or adjusted to let in welcome solar heat in winter time, which
will reduce the load on the active heating system.
• Better utilisation of natural daylight and better daylighting strategy - The
curtain can be adjusted to let daylight into the room , which reduces the energy
requirement for artif cial lighting (internal heat load) by up to 80%.
• Glare protection - The slats can be adjusted to provide glare protection while,
at the same time, directing the daylight - important for computer work.
• Increased comfort - Mirror slats are normally mounted behind glazing,
resulting in relatively high glass surface temperatures despite a low
transmission of energy (referred to the room).
• Heat loss through windows - Closed curtains can signif cantly reduce the
heat loss through windows during winter.
• Contact to the outside world - Since the curtain is very f exible, contact to
the outside world is ensured at all times.
FAC T SH E E T Lig h t-d irec tin g B linds
IMPORTANT PARAMETERS and Typical Performance
Energy transmittance value (g value), total energy transmittance value (gtotal value) and shading coeff cient (Fc)
The energy transmittance value (g value) is the fraction Example - Light-directing blind
of solar radiation that enters through the window and is
Glass g = 0.65 (according to EN 410)
converted to heat in the room. The energy transmission is Glass + solar shading gt = 0.10 (acc to EN 13363)
composed of the direct transmission and the secondary
Shading coeff cient Fc = gt/g = 0.15
heat transmission of the glazing.
As slats are tiltable, the shading coeff cient can be adjusted as required.
The total energy transmission value (gtotal or gt) indicates the energy transmission for a system that compris- Cooling period - solar shading activated
gt = 0.10 - The load on the room climate is only 15% of
es the glazing and the shading; this value is determined
the sun energy (corresponds to passive house standard).
according to EN 13363.
The quality of a shading system is def ned by the shading coeff cient (Fc value) - Fc = gt/g. The lower this
value, the more eff cient is the sun protection.
Fc = 1.0 … no shading
Fc = 0.1 … very good shading
Heating period - solar shading deactivated
gt = g = 0.65 - 65 % of the solar energy can be
utilised for heating.
Effect on energy consumption
Cooling period: energy saving of approx 30 kWh/m2
a and more
Heating period: energy saving of up to 10 kWh/m2a
Heat transfer coeff cient (U value), reduction of heat loss through the window
Depending on the user behaviour, the glazing, the glazThe U value (formerly k value) is the measured value of
ing percentage and the installation position and tightness
the heat transfer through a component; it is indicated in
W/m2K. The smaller the U value the better, as less heat is of the curtain, an improvement of the U value by 5 - 10 %
can be achieved.
transferred through the component.
Example - passive house
U value wall 0.12 W/m2K
U value window 0.80 W/m2K
Effect on heating energy requirement
Saving of up to 5 kWh/m2a
Light transmission (TL or LT), reduction of power requirement for lighting
Ref ector slats that follow the sun offer more eff cient
The light transmittance TL indicates how much of the
daylight utilisation than shading systems mounted in front
visible light spectrum (380 nm to 780 nm) is transmitted
of or behind the glazing over the entire window.
through a glazing, in percent.
A high light transmission value of the glazing (TL > 80 %)
is required to ensure good lighting of the room.
Other
Wind resistance during use
Expected serviceable life
Saving of artif cial light requirement during the day:
up to 30 kWh/m2a
Not relevant (light-directing systems are protected
against outside inf uences by the window glass.
Requirement approx 15 years (+/- 5)
The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of
a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the
individual case, many parameters must be considered depending on the specific object, with different results.
• With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection
• With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains
• With regard to the lighting, the values refer to a simple, manually controllable glare protection.
Energy values refer to the end energy.
Dy n a m i c e x t e r n al s o lar s h ad in g
EX TE R N A L V E N E T IA N B L IN D S
PRODUCT DESCRIPTION
The typical characteristic of external Venetian blinds, often called outside Venetian blinds, is the curtain of horizontal slats that can be tilted, raised and lowered.
The tilting allows adjustment of the position of the slats in relation to the position of the sun in order to ensure good view to the outside and optimum use of
free, natural daylight. Of course, it is possible to raise all the slats, for instance
when there is no direct solar radiation or, conversely, if free solar gains are to be
utilised.
External Venetian blinds are highly eff cient, versatile shading systems that can
be adapted very well to the outside climatic conditions, being adjustable and
retractable.
When solar radiation is too strong, up to 90% of the incident solar energy can be
blocked by external Venetian blinds, by ref ection and absorption of the energy,
so that overheating of the interior of the building is avoided and load on active
cooling systems is drastically reduced - passive cooling.
External Venetian blinds, in connection with motorised drives, a well designed
control system and openable windows ensure that no or only little cooling energy
is required during the day, while ensuring eff cient cooling at night; besides, they
provide the necessary protection of the private sphere.
greenhouse effect. Signif cant reduction of heat transmission from outside; the
load on the active cooling system can be minimised and/or active cooling is not
necessary at all.
• Use of free, renewable solar heat gains / passive heating - The curtain can be
retracted to let in welcome solar heat in winter time, which will reduce the load on
the active heating system.
• Better utilisation of natural daylight and better daylighting strategy - Adjusting
the slats according to the position of the sun allows optimum use of natural
daylight, while at the same time providing protection against the sun. When
selected properly (slat colour and size), the blinds will allow reduction of the energy
need for artif cial lighting, which indirectly helps reduce the load on any active
cooling system.
• Glare protection - Reduces the luminance values (the brightness of the light)
at the workspace whenever required by law or for better comfort (e.g. computer
work).
• Increased comfort - The surface temperature of the glazing - and thus the room
temperature - is considerably reduced when the sun is high and the blinds are
down. During the heating period, a retracted blind will ensure relatively higher
temperatures on the glass surface, which helps heat the building.
• Heat loss through windows - During winter, fully closed blinds (at night) can also
help slightly reduce the heat loss through windows - depending on the U value of
these.
• Contact to the outside world - As the slats are very f exible and can be adjusted
as desired, contact to the outside world is ensured at all times.
FAC T SH E E T Ex tern al Ven etian Blinds
The energy transmittance value (g value) is the fraction
converted to heat in the room. The energy transmission is
The total energy transmission value (gtotal or gt) indicates the energy transmission for a system that comprises the glazing and the shading; this value is determined
Example - external Venetian blind
Glass + solar shading gt = 0.11 (acc to EN 13363)
As slats are tiltable, the shading coeff cient can be adjusted as required)
Cooling period - solar shading activated
a and more
Depending on the user behaviour, the glazing, the glazThe U value (formerly k value) is the measured value of
ing percentage and the installation position and tightness
W/m2K. The smaller the U value the better, as less heat is of the curtain, an improvement of the U value by 5 - 10 %
can be achieved.
Saving of up to 5 kWh/m2a
Slats that can be adjusted in relation to the position of
the sun ensure a more eff cient utilisation of daylight
than continuous shading systems mounted in front of or
behind the glazing.
Saving of artif cial light requirement during the day:
up to -15 kWh/m2a
Other
approx 10-20 m/s
approx 10-20 years
Dy n a m i c e x t e r n al s o lar s h ad in g
RO L L E R S H U T T E R S
PRODUCT DESCRIPTION
Roller shutters are characterised by a curtain made of many horizontal prof led
bars (mostly made of aluminium, plastic or wood) hinged together. These can
be raised to open and can be closed tightly for solar protection and darkening
purposes; to some extent, roller shutters fulf l some of the security requirements
of the user. The entire curtain can be raised, for instance when there is no direct
solar radiation or if free solar gains should be used.
Special designs may have adjustable slats (similar to blinds) or special prof les to
ensure that more natural daylight is utilised better.
Roller shutters are very eff cient passive shading systems that can be adapted
well to the outside climatic conditions (height adjustable).
If solar radiation is too strong, up to 85% of the incident sun energy can be
blocked (ref ected and absorbed) from the interior of the building drastically reducing the use of active cooling systems.
During the heating period, signif cant solar gains can be achieved as the shading
can be deactivated (retracted).
Roller shutters, in connection with motorised drives, a well designed control system and openable windows ensure that no or only little cooling energy is required
during the day, while ensuring eff cient cooling at night; besides, they provide the
necessary protection of the private sphere.
necessary at all.
• Use of free, renewable solar heat gains / passive heating - The curtain can be
retracted to let in welcome solar heat in winter time, which will reduce the load on
the active heating system.
• Better utilisation of natural daylight and better daylighting strategy Depending on the height of the curtain, the amount of daylight can be regulated
from 0 - 100%. Roller shutters are consequently particularly suited for relaxation
rooms or bedrooms.
• Glare protection - Only ensured to a minor extent if curtain is almost closed.
Consequence: no contact to the outside world, artif cial light must be switched on.
• Increased comfort - The surface temperature of the glazing - and thus the room
temperature - is considerably reduced when the sun is high and the curtain is
down. During the heating period, a closed curtain will ensure relatively higher
temperatures on the glass surface, which helps heat the building.
• Heat loss through windows - Roller shutters can signif cantly reduce the heat
loss through windows during winter - depending on the U value of these (between
10 and 40 %).
• Contact to the outside world - Roller shutters with adjustable slats or specially
shaped daylight prof les ensure contact to the outside world even when the curtain
is closed.
FAC T SH E E T Ro lle r S h u tte rs
Example - Roller shutter
a and more
The U value (formerly k value) is the measured value of
W/m2K. The smaller the U value the better, as less heat is
Improvement of the U value depending on the material
of the curtain and the tightness of the system in percent
according to EN ISO 10077-1:
3-pane insulating glass (UG 0.8 W/m2K) 7-17%
2-pane insulating glass (UG 2.1 W/m2K) 16-35%
Non insulating glass (UG > 3.0 W/m2K) 20-44%
Saving of 5 to 30 kWh/m2a
Continuous shading systems reduce the incident light
(shading principle). In order to reduce the artif cial light
requirement, the height of the curtain must be adapted to
the outside light conditions.
Conventional roller shutters: additional energy consumption of > 5 kWh/m2a
Daylight roller shutters: saving of up to 10 kWh/m2a
Other
approx 20-30 m/s
approx 15-25 years
D y na m i c e x t e r n al s o lar s h ad in g
R O LL E R B L I ND S a n d AWN IN GS
PRODUCT DESCRIPTION
Roller blinds and awnings are characterised by a curtain made of textile that normally has a transmission value of 2-15% so that one can see through it; besides,
the entire curtain can be retracted, for instance when there is no direct solar
radiation or, conversely, if free solar gains are to be utilised.
When solar radiation is too strong, up to 80% of the incident solar energy can be
blocked by external roller blinds and awnings, by ref ection and absorption of the
energy, so that overheating of the interior of the building is avoided and load on
active cooling systems is drastically reduced - passive cooling.
Roller blinds and awnings, in connection with motorised drives, a well designed
control system and openable windows ensure that no or only little cooling energy
is required during the day, while ensuring eff cient cooling at night.
necessary at all.
be retracted to let in welcome solar heat in winter time, which will reduce the
load on the active heating system.
• Better utilisation of natural daylight and better daylighting strategy
- Transparent screens ensure utilisation of daylight while simultaneously
providing protection against the sun.
• Glare protection - Reduces the luminance values (the brightness of the
light) at the workspace whenever required by law or for better comfort (e.g.
computer work).
• Increased comfort - The surface temperature of the glazing - and thus the
room temperature - is considerably reduced when the sun is high and the
blinds are down. During the heating period, a retracted blind will ensure
relatively higher temperatures on the glass surface, which helps heat the
building.
• Heat loss through windows - During winter, fully closed blinds (at night) can
also help reduce the heat loss through windows - depending on the U value of
these.
• Contact to the outside world - The view through a textile shading system is
determined by its transparency, type of holes and colour of the fabric.
FAC T SH E E T Ex tern al R o lle r B linds and Awnings
Example - Awning
a and more
Depending on the user behaviour, the glazing, the glazing percentage and the installation position and tightness
of the curtain, an improvement of the U value by 5 - 20 %
can be achieved.
Saving up to 5 kWh/m2a
Continuous shading systems reduce the incident light. In
order to reduce the artif cial light requirement, the height
of the curtain or the light transmission must be adapted
to the outside light conditions.
Higher use of artif cial light during the day, > 5 possible
Other
approx 10 m/s (+/- 5)
approx 10-15 years
D y na m i c I n d o o r S o lar S h ad in g
A LL I N D O O R P R O D U C T S
(b l i n d s , f a b ri cs , c u rta in s, fo ils )
PRODUCT DESCRIPTION
The characteristic of indoor shading systems is that they are installed inside the
room; due to the physical conditions (conversion of sun energy into thermal radiation) this results in a relatively low sun protection effect. Only highly ref ecting and
pure white surface achieve more favourable values thanks to their high degree of
ref ection.
The type and the materials used for indoor shading devices are relatively insignif cant in terms of the sun protection effect; aluminium slats, foil roller blinds and
textile curtains differ primarily by their glare protection effect and by the degree of
utilisation of daylight.
As far as energy balance is concerned, a combination of indoor shading devices
and insulation glazing offers better results than a combination of indoor shading
devices and sun protection glazing; even though overall energy transmission is
slightly better if sun protection glazing is used, due to the low daylight transmission, the energy requirement for illumination and thus also the cooling required
due to the electrically generated internal thermal loads will increase; also, the
usable solar gains decrease during the heating period.
In connection with a well-thought out control and openable windows, indoor shading devices contribute to lowering the cooling energy requirement during the day
while ensuring eff cient cooling at night; in addition, some systems provide the
necessary protection of the private sphere.
• Sun protection /passive cooling - Moderate reduction of heat transmission
from outside; the requirement for active cooling may be minimised.
be retracted to let in welcome solar heat in winter time, which will reduce the
load on the active heating system.
• Better utilisation of natural daylight and better daylighting strategy Adjustable slats and height-adjustable curtains allow optimum use of natural
daylight, while at the same time providing protection against the sun. When
selected properly (slat colour and size), the blinds will allow reduction of the
energy need for artif cial lighting, which indirectly helps reduce the load on any
active cooling system.
• Glare protection - Reduces the luminance values (the brightness of the
light) at the workspace whenever required by law or for better comfort (e.g.
computer work).
• Increased comfort - The surface temperatures of indoor shading systems
are generally higher than those of comparable outdoor shading devices; this
may result in discomfort during summer, whereas in winter, this is usually
experienced as comfort.
• Heat loss through windows - Closed curtains can signif cantly reduce
the heat loss through windows - depending on the U value of these. (In
comparison, the heat loss is less than for outside shading systems).
• Contact to the outside world - As the curtains are very f exible and can be
adjusted as desired, contact to the outside world is ensured at all times.
FAC T SH E E T all in d o o r so lar s h adings ( blinds, f abrics, curt ains, f oils)
The energy transmittance value (g value) is the fraction Example - Textile inside shading
converted to heat in the room. The energy transmission is Glass + solar shading gt = 0.40 (acc to EN 13363)
gt = 0.40 - - The load on the room climate is only 40% of
The total energy transmission value (gtotal or gt) indicates the energy transmission for a system that compris- the sun energy. Values above 0.25 normally do not suff ce to cover peak loads.
es the glazing and the shading; this value is determined
a and more
Two-dimensional shading systems reduce the incident
light (shading principle). In order to reduce the artif W/m2K. The smaller the U value the better, as less heat is cial light requirement, the height of the curtain must be
adapted to the outside light conditions.
Continuous glare protection: additional energy
consumption of > 5 kWh/m2a
Glare protection slats: saving of < 5 kWh/m2a
Depending on the adjustability of the curtains, light
control between 5 and 100 % is possible (tightly closing
systems may also darken a room).
For light, tiltable slats up to 10 kWh/m2a
Higher artif cial light requirement for textile shading systems
Other
Not relevant
approx 10 years (+/- 5 years)
Sta tic e x t e rn al s o lar s h ad in g (s wivelling or rigid)
Ho r iz o n t a l SO L A R F IN S , L O U V E RS and BALCONIES
PRODUCT DESCRIPTION
Horizontally mounted rigid or swivelling shading devices (protruding or mounted
to the front) normally fulf l architectural requirements, while simultaneously
offering protection against the sun and a largely unobstructed view.
Horizontally protruding systems are suited as sun protection for facades facing
South; swivelling louvers mounted to the front are suited for low sun altitudes at
Eastern and Western facades. Normally, the f ns are made of aluminium, while
some are made of glass, stainless steel or fabric.
Compared to outside dynamic solar shading systems, horizontally mounted
louvers (rigid or swivelling) feature good sun protection values. As these shading
systems are permanently present, they can be adapted to different outside
conditions only to a certain extent, resulting in a reduced utilisation of diffuse
daylight (natural light) and solar gains (passive heating).
The low f exibility of the systems consequently also affects the energy balance
(cooling, heating, light). Accurate planning of the system is required to ensure
optimal sun protection.
Front-mounted swivelling shading devices, in connection with motorised drives, a
well designed control system and openable windows ensure that no or only little
cooling energy is required during the day, while ensuring eff cient cooling at night.
The performance data for non-swivelling systems are accordingly lower, with a
negative effect on the energy balance.
• Sun protection /passive cooling - Moderate reduction of heat transmission
from outside; however, the load on active cooling systems can be minimised.
In the case of horizontally protruding systems on a lightweight construction,
thermal problems might still be experienced in the building when sun is low.
• Use of free, renewable solar heat gains / passive heating - Normally, the
system does not provide shading when the sun is low; solar heating is thus
ensured.
• Better utilisation of natural daylight and better daylighting strategy Rigid horizontal shading systems hardly allow for any utilisation of the zenith
light; swivelling louvers, on the other hand, may transmit daylight.
• Glare protection - When the sun is low, additional glare protection (mounted
on the inside) is required.
• Increased comfort - Protruding louvers only shade the glass surface when the
sun is high, however, the introduced heat is highest when the sun is low. Frontmounted swivelling louvers may reduce the surface temperature of the glazing
and thus the room temperature.
• Heat loss through windows - Due to the design of the system, the heat loss
through windows during winter cannot be reduced.
• Contact to the outside world - Contact to the outside world is ensured at all
times.
FAC T SH E E T Ho rizo n tal S o larfin s, Louvers and Balconies
The total energy transmission value (gtotal or gt) indicates the energy transmission for a system that comprises the glazing and the shading.
The effectiveness of a permanent horizontal shading is
def ned by the shading coeff cient (F0 value) in
DIN V 18599-2; it depends on the position of the sun, the
orientation of the façade and the form of the shading, and
is in the range between 0.6 and 1 (1 no shading effect).
Example - Large horizontal louvers
Glass + solar shading gt = 0.39 (acc to DIN V 18599-2)
Best shading coeff cient F0 = 0.6 (South-facing facades)
Cooling period (sun protection depends on position
of the sun)
gt = 0.39 - In the best case scenario, the load on the
room climate is only 39% of the sun energy. Values
above 0.25 normally do not suff ce to cover peak loads.
Heating period (utilisation of solar energy depends
on position of the sun)
Provided the systems do not produce an own shade, up
to 65% of the solar energy can be used for heating when
the sun is low.
Cooling period: energy saving of up to 10 kWh/m2a
(effect is lower for unfavourable arrangement)
No improvement is possible.
Saving of 0 kWh/m2a
A permanently mounted shading system will result in a
loss of valuable daylight (diffuse radiation) particularly
during times of the day and year with little light.
Increased requirement for artif cial light during the day,
> 5 kWh/m2a
Other
Requirement > 30 m/s (as non retractable)
approx 10-20 years
Sta tic e x t e rn al s o lar s h ad in g (s wivelling or rigid)
Ve r ti c a l SO L AR F IN S a n d L O U V ERS
PRODUCT DESCRIPTION
Vertically mounted, swivelling louvers and solar f ns must fulf l architectural
requirements, while simultaneously offering protection against the sun and an
unobstructed view.
Vertical louvers and solar f ns are suited as sun protection in particular for Eastern and Western facades, however, they may also be used for facades facing
South. Normally, the f ns are made of aluminium, while some are made of glass,
stainless steel, metal or fabric. To ensure visual contact to the outside world also
when closed (when sun is low), metal systems are often perforated.
Most systems provide only a moderate shading effect and daylight utilisation;
however, they do ensure good contact to the outside world. If the distance to the
glazing is large, daylight utilisation, in particular of the zenith light part, can be
reduced signif cantly owing to the produced own shade. The performance data
for swivelling systems are signif cantly better.
Accurate planning of the system is required to ensure optimal sun protection.
Swivelling vertical louvers, in connection with motorised drives, a control system
that automatically follows the sun, and openable windows ensure that only little
heat is introduced during the day, while ensuring eff cient cooling at night.
The performance data for non swivelling systems are accordingly lower, which
normally affects the energy balance negatively.
• Sun protection /passive cooling - Depending on the type of product, good
to moderate reduction of the introduced heat; the load on the active cooling
system can be reduced and/or active cooling is not necessary at all.
• Use of free, renewable solar heat gains / passive heating - The f ns can
optionally be opened towards the sun to reduce the load on the active heating
system during the heating period.
• Better utilisation of natural daylight and better daylighting strategy Adjusting the f ns according to the position of the sun allows optimum use of
natural daylight, while at the same time providing protection against the sun.
Rigid louvers, on the other hand, increase the artif cial light requirement.
• Glare protection - Only swivelling systems combined with separate glare
protection can reduce luminance values (the brightness of the light) at the
workspace whenever required by law or for better comfort (e.g. computer
work).
• Increased comfort - Only swivelling f ns reduce surface temperatures of the
glazing - and thus the room temperature - when the sun is high.
• Heat loss through windows - Normally, the heat loss through windows
cannot be reduced due to the design of the system.
• Contact to the outside world - As the f ns are f exible and can be adjusted as
desired, contact to the outside world is ensured at all times.
FAC T SH E E T Ve rtica l S o larfin s a nd Louvers
The total energy transmission value (gtotal or gt) indicates the energy transmission for a system that comprises the glazing and the shading.
The effectiveness of a permanent vertical shading is def ned by the shading coeff cient (F1 value) in
DIN V 18599-2; it depends on the position of the sun, the
orientation of the façade and the form of the shading, and
is in the range between 0.6 and 1 (1 no shading effect).
Example - Large vertical louvers
Glass + solar shading gt = 0.42 (acc to DIN V 18599-2)
Best shading coeff cient F1 = 0.65 (East- and Westhfacing facades)
Cooling period (sun protection depends on position
of the sun)
gt = 0.42 - In the best case scenario, the load on the
room climate is only 42% of the sun energy. Values
above 0.25 normally do not suff ce to cover peak loads.
Heating period (utilisation of solar energy depends
on position of the sun)
Provided the systems do not produce an own shade, up
to 65% of the solar energy can be used for heating when
the sun is low.
(effect is lower for unfavourable arrangement)
Saving of 0 kWh/m2a
A permanently mounted shading system will result in a
loss of valuable daylight (diffuse radiation) particularly
during times of the day and year with little light.
Increased requirement for artif cial light during the day,
> 5 kWh/m2a
Other
Requirement > 30 m/s (as non retractable)
approx 10-20 years
P e r m a n e n t , s elec tive s u n p ro tect ion
S UN PR O T EC T IO N GL A S S a n d S UN PROTECTION FOILS
PRODUCT DESCRIPTION
Sun protection glass and foil-laminated (laminated) glass primarily fulf l architectural requirements, ensuring “strut free” or respectively “unobstructed” contact
to the outside world. The sun protection function results from the selection of
specif c wave lengths, i.e. specif c sun spectra, primarily short-wave infrared, are
f ltered out. Systems with a low g value (g < 0.4) also f lter out part of the visible
light; this results in a low light yield and a colour shift of the daylight.
Due to the technology used, sun protection glass and laminated glazing have an
unfavourable energy balance; they cannot reduce the energy input to the same
extent as outside shading systems (ratio approx. 3:1). As they are permanently
active, the solar gains for heating are reduced to a minimum. Besides, with an
increasing sun protection effect, utilisation of daylight decreases or respectively
the requirement for artif cial illumination increases (percentage of electrically
produced internal thermal loads increases). Trying to compensate for a reduced
light yield by increasing the glazing part will result in increased heat losses. Sun
protection glass and laminated glazing are also effective when there is no functional necessity for it!
• Sun protection /passive cooling - Suff cient to cover the basic load to
prevent over-heating during summer. Additional passive or active measures
are required for peak loads.
• Use of free, renewable solar heat gains / passive heating - Not ensured to
a suff cient degree (not approved for passive house standard).
• Better utilisation of natural daylight and better daylighting strategy Utilisation of daylight decreases the higher the sun protection!
• Glare protection - A dynamic glare protection mounted on the inside is
required when sun is low.
• Increased comfort - As the glass surfaces are not positioned behind louvers
or fabric, the surface temperatures are relatively high when the sun shines on
them.
• Heat loss through windows - Sun protection lamination does not improve the
U value of glazing.
Increasing the part of the non-laminated glass surface to compensate for the
daylight loss will result in increased losses of heating energy (deterioration of
the U value of the façade).
• Contact to the outside world - Contact to the outside world is ensured at all
times.
FAC T SH E E T Su n P ro tec tio n G lass and Foils
The energy transmittance value (g value) is the fraction Example - Sun protection glass without additional
shading
converted to heat in the room. The energy transmission is Glass g = 0.35 (according to EN 410)
the sun energy. Values above 0.25 normally do not sufFor sun protection glass, a shading coeff cient is already
f ce to cover peak loads
included in the system (lamination); for additional shading
systems, gt must be calculated according to EN 13363-2.
30 to 65 % solar energy gains less result in accordingly
higher heating requirement.
The total energy transmission value (gtotal or gt) indicates the energy transmission for a system that compris- Effect on energy consumption
es the glazing and the shading.
Heating period: additional energy requirement of up to 10
kWh/m2a
The result of the energy balance (saving for cooling relative to increased heating requirement and power requirement for lighting) may also be negative. Sun protection
glazing may therefore not be installed in passive houses.
Saving of 0 kWh/m2a
For g values < 0.45, the visible light is selectively blocked
(20 - 50 %), resulting in an increased requirement for
artif cial light. Increasing the percentage of the glass
surfaces cannot compensate the light loss, but causes a
higher cooling load and heating energy requirement.
Increased requirement for artif cial light
of 5 to 15 kWh/m2a
Other
Requirements according to national standards
Requirement: 20 years (+/- 5)
FAC T SH E E T
Imprint
Keep Cool II is an projekt of IEE Intelligent Energy Europe
Project management: Barbara Dröschel, IZES GmbH, www.izes.de
Published and produced by: ES-SO Europeas Solar Shading Organization
ES-SO vzw, Naessenslaan 9, B-1860 Meise, Belgium, Tel: +32-475-27 47 42, Email: [email protected], HP www.es-so.eu
Author: J. Gesrtmann, SLS Praun & Gesrtmann GmbH, Graz, www.s-l-s.at
Other
Reviewing: Author: J. Gerstmann, SLS Praun & Gesrtmann GmbH, Graz, www.s-l-s.at
Layout: Author: SLS Praun & Gerstmann GmbH, Graz, www.s-l-s.at
Images: SLS Praun & Gerstmann, ES-SO, Somfy
The sole responsibility for the content of this report lies with the author.
The
values
listed in the
values
from tests and simulations and refer to a building situated at the outskirts of
It does
not represent
thefactsheets
opinion ofare
theaverage
European
Communities.
aThe
city;European
they should
indicate
the
potential
of
solar
shading
terms
of of
energy
savings. The
values are
not applicable in the
Commission is not responsible for any useproducts
that mayinbe
made
the information
contained
therein.
allowed
parts
and energy,
with detailed
reference
•Reprint
With regard
to in
the
cooling
the values
refer only.
to a conventional two-pane insulating glass without sun protection
on non-chlorine
bleached
paper.
•Printed
With regard
to the heating
energy,
the values refer to a two-pane sun protection glass with low solar gains
PART B
Report on Passive Cooling Solutions
Products for Passive Cooling
Night Ventilation
The thermal storage capacity of materials can be used to reduce the
peaks of temperature in buildings. During summer, thermal mass
can be used to lower the upper daytime temperature, thereby
reducing the need for cooling. The over a day warmed-up thermal
mass is cooled by night time ventilation, when outdoor temperatures
are low, and allow heat dissipation at the following day when indoor
temperatures are high. If a night-ventilation-system is performed
well, the building has got adequate thermal mass and solar gains
are reduced to a minimum, the installation of an active cooling
system can be dispensable.
Free night ventilation is operating due to the density difference of
internal and external air; density is a function of the temperature.
Because night temperatures are - at least in central Europe - mostly
under 21°C and room temperatures are higher, a dens ity difference
is most of the time effective. Wind also generates pressure
differences between air-inlet- and -outlet-openings. To do efficient
night ventilation it is indispensable that the building can be good
flown through by air.
Free night ventilation via opened windows can achieve air flow rates
-1
from 10 h and more. Free ventilation can also be realized with
overflow-elements in the façade.
The thermal mass of a building is the stabilisation-element of the
room temperature. The bigger thermal mass, the more evenly the
room temperature. Big thermal masses (density x specific heat
capacity) are making temperature-vacillations smoother. For the
temperature-vacillation within a day the surfaces in the room are
crucial. The heat-penetration-coefficient is a mass of the short-termheat-impact. The higher the heat-penetration-coefficient, the faster
heat can be absorbed or emitted. So, heat peaks can be absorbed
at day and given off from the building component at night. If there is
too less thermal mass existing, overheating will take place.
With heat loaded thermal mass has to be cooled with fresh external
air during night and early in the morning. Short time ventilation and
ventilation at morning is not sufficient, the penetration time is too
short. The recooling period should take at least 5 hours. Ideally night
ventilation should take place from 10pm to 10am.
Night Ventilation
1/2
Boundary conditions for free night cooling:
o
o
o
o
o
o
o
The (daily total) cooling load of the building should not be
higher than 150 Wh/m²d (external shading!)
The building should own an adequate thermal mass
An operative air change during day should be done
Night ventilation of at least 5 hours per night when the
external air temperature is under 21°C.
-1
Air change rate should be (much) more than 2 h
Free night ventilation only implementing, when the building
can be streamed through well by air; burglary and weatherprotections are existing.
Mechanical night ventilation only, if free ventilation is not
feasible
With the help of thermal building simulation programmes, room
temperatures of buildings in dependence of the construction and the
weather can be determined.
Zimmermann, M.; Rationelle Energienutzung in Gebäuden; Handbuch der passiven Kühlung; EMPA
ZEN; 1999
Blümel, E., Fink, C., Kouba R.; Passive Kühlkonzepte für Büro- und Verwaltungsgebäude; Leitfaden
zur Planung von passiven Kühlkonzepten mittels Nachtlüftung und luft- bzw. wasserdurchströmten
Erdreichwärmetauschern; Programmlinie Haus der Zukunft des bm:vit; 2002
N.N.; Specialist Natural And Energy Efficient Ventilation Applications; http://www.passivent.com/;
17.02.2008
Pfafferott, J.; http://www.bine.info/fileadmin/content/Publikationen/Themen-Infos/I_2003/themen0103internet-x.pdf, BINE Informationsdienst, 18.02.2009
Night Ventilation
2/2
Burglary and weather protection for
free ventilation
To guarantee undisturbed free- and night-ventilation, it is important
that weather occurrences don’t influence its operation and the walland window-openings are burglar-proofed. Free night ventilation can
be done via opened or tilted windows and via overflow elements
integrated in the façade, roofs or windows. There are loads of
possibilities to configurate overflow-elements and protect opened
windows.
Overflow elements situated in walls and windows have to be
equipped with weather- and insect-protection and with an automatic
controlled ventilation flap. Such elements can be integrated in the
building during construction or they can be adapted in an existing
building.
Burglary and weather protection for free ventilation
1/2
Windows can be opened manually or automatically to
generate an air flow. In both cases weather- and burglarprotection can be guaranteed.
Burglar protection can be done with:
o window grills
o automatic window-chain-drives and spindle drives
are protecting tilted windows
o lockable window brackets by tilted windows
o construction preventatives
o roller shutter
o blinds
o sun protection devices in front of windows
(lamellae)
o etc.
Weather protection can be managed with:
o automatically window closing with the assistance
of rain- and wind-sensors
o reeled out roller shutters or blinds
o construction preventatives
o sun protection
o bottom-up tilted windows
o forward situated façade
o etc.
Insurance coverage must be warranted in both cases.
Protection-measures must be approved by insurances
explicitly.
Sources:
http://www.somfy.at/
http://www.dh-partner.com/en/dh-gruppe.asp
http://www.colt-info.de/produkte-systeme/brandschutz/produkte/euroco/
http://www.alukoenigstahl.com
http://www.wicona.de;
http://www.dorma.at
http://www.passivent.com/
http://www.wohnatelier.de/innenausbau/fenster_einbruchschutz.htm
Burglary and weather protection for free ventilation
2/2
Plaster and plasterboard
integrated with
Phase-Change-Material
Systems that use Phase Change Materials (PCM) can be used to
store energy and they increase the thermal mass of a building. All
substances store energy when their temperature changes, but
when a phase change occurs in a substance, the energy stored is
higher. Furthermore, heat storage and recovery occur
isothermally, which makes them ideal for space heating /cooling
applications.
Microscopically plastic-capsules with a core made of wax get
insert into the plaster or plaster-boards during fabrication. The
melting temperature of the wax can be defined during
manufacturing. If the room temperature is rising above this
melting point (around 21 to 26 °C), wax gets liquid and it absorbs
the surplus of room-heat. If room-temperature is falling, the wax is
getting hard and is giving heat to the room-air. For the periodical
melting and solidification, air-temperature differences during day
and night are used, for example via night ventilation.
The PCM-primary-product (Micronal PCM from basf) is delivered
as liquid dispersion or as powder. During manufacturing it is
added to plaster, plasterboards, spackle or chipboards.
BASF started to merchandise the PCM-primary-product Micronal®PCM in 2004. 2005 maxit Germany GmbH has taken a plaster
containing Micronal PCM into their product assortment, called
maxit clima.
All constructions integrated PCM have to be regenerated during
night to have a sufficient heat storage capacity next day. This
regeneration can occur via night ventilation, with integrated
capillary tubes or if existing via static cooling systems or air
conditioning.
Plaster and plasterboard integrated with Phase-Change-Material
1/2
In the following table plaster-boards integrated with PCM are
faced to a conventional one [1]:
Parameter
Micronal
PCM
Smartboard
23
Micronal
PCM
Smartboard
26
Standard
plaster
board
Switch-temperature
23 °C
26 °C
-
Latent heat capacity at
the switch point
330 kJ/m²
330 kJ/m²
0 kJ/m²
Specific heat capacity
1.2 kJ/kgK
1.2 kJ/kgK
0.85 kJ/kgK
Heat conduction
0.18 W/mK
0.18 W/mK
0.19 W/mK
There is available the simulation software PCMexpress,
whereby it is possible to generate a building and simulate a
trend of room temperatures over a year. The result shows the
impact of PCM-components to the room temperatures
compared to conventional materials.
Available products:
Plaster: Maxit clima 21, 26
Plasterboards: micronal pcm smartboard 21, 23, 26
Primary product: Micronal® PCM
N.N.; plasterboards; http://www.micronal.de/portal/basf/ien/dt.jsp?setCursor=1_290798; 17.02.2008
Plaster and plasterboard integrated with Phase-Change-Material
2/2
Air-ground-heat-exchanger
Air-ground-heat-exchangers are air-flown plastic-, concrete- or fibrecement-tubes which are horizontally placed in the ground. The nearly
constant temperature of the ground in a certain depth is utilized.
External air gets pre-cooled in summer or pre-heated in winter before it
reaches the ventilation system of the building. In the following figure
there is shown the temperature-trend through an air-ground-heatexchanger in summer. They are placed either in the foundation of a
building or in a free surface in a frost free depth. The ground serves as
thermal mass which balances heat seasonal and day wise.
Those ground register should be applied in such climate where large
temperature differences between summer and winter as well as
between day and night occur.
Example of a temperature profile through an air-ground-heat-exchanger
1/2
The functional principle of air-ground-heat-exchangers is quite
simple. Although there exist a number of parameters, which
influences the performance of the exchanger. Beside factors
which have a direct impact on the power of the exchanger
(flow-rate, tube diameter, laying depth, length, material and
ground consistence) there are some indirect factors (drop in
pressure through the exchanger, impact of air-hygienic,
investment costs and so on) which have to be considered by
planning and construction.
The biggest sensitivity of the cooling capacity shows the flowrate-parameter. Although the drop in pressure through the
tubes is from a decisive impact. Further parameters with a
decisive impact are the length of the air-ground-heatexchanger, the laying depth and the ground consistence. A
low impact of the cooling capacity shows the tube-diameter
and the tube-material.
The air ground heat exchanger must not be overloaded during
a season. The operating time of the air flow rate through the
exchanger should be tuned to the capacity of the ground.
Basically the flow rate through the heat exchanger should not
be very much higher than the hygienic one.
Cooling power is a function of:
Dimensioning (rool-of-thumb):
Air velocity through the register:
Drop in pressure per tube:
Distance betweet single tubes:
Tube length:
Laying depth:
Air flow rate
Tube-diameter
Laying depth
Length of heat exchanger
Ground consistence
1 – 5 m/s
1 – 1.5 Pa/m per tube
Around 1 m
> 30 m
1.5 – 4 m
Ideal dimensioned air-ground-heat-exchangers reach a
specific cooling energy gain of 300 Wh/m²d. Based on the
laying area, a specific cooling power of 40 to 60 W/m² can be
determined.
Blümel, E., Fink, C., Kouba R.; Passive Kühlkonzepte für Büro- und Verwaltungsgebäude; Leitfaden
zur Planung von passiven Kühlkonzepten mittels Nachtlüftung und luft- bzw. wasserdurchströmten
Erdreichwärmetauschern; Programmlinie Haus der Zukunft des bm:vit; 2002
ZEN; 1999
2/2
Decentral air conditioning appliance
integrated with PCM
Systems that use Phase Change Materials (PCM) can be
used to store energy. All substances store energy when their
temperature changes, but when a phase change occurs in a
substance, the energy stored is higher. Furthermore, heat
storage and recovery occur isothermally, which makes them
ideal for space heating /cooling applications.
With decentral air conditioning appliances integrated with
PCM it is possible to cool a building without active cooling
system. These devices are using the temperature difference of
the external air between night and day. At day external air
gets cooled by the PCM-storage module before it reaches the
room. The heat of the external air gets stored in the PCMpackage. At night the package gets regenerated with cool
external air.
Decentral air conditioning appliance integrated with PCM
1/2
In the device integrated is one heat exchanger for heating or
cooling function. If the cooling power of the PCM-package
doesn’t suffice, the heat exchanger can deliver additional
cooling power. The mode of operation is either circulation-aircooling or fresh-air-cooling.
Basically, cooling power is resulting out of the temperature
difference between melting-point of the PCM-package and the
room-air-temperature as well as the air flow rate through the
package.
Melting point and heat capacity of a PCM-package:
20 °C and 30 Wh/kg
Rated air flow per device:
3
≈ 160 m /h
Dimensioning parameters for cooling loads up to 50 W/m²:
mPCM ≈ 5,5 kg/m²
Sources:
N.N., PCM air conditioning device, http://www.emco-klima.de/de/d/607/koid/22/start/0/produktfinder.
20.html, 23.02.2009
N.N., PCM-package: http://www.sglgroup.com/cms/international/products/product-groups/eg/coldstorage-systems-for-engine-off-operation-of-truck-air-conditioning/index.html?__locale=en
Decentral air conditioning appliance integrated with PCM
2/2
Direct cooling
with ground energy source
Ground shows a relative constant temperature of around ten
degrees in a certain depth. Thermodynamically viewed it can
be used directly as cold source for room cooling applications
where temperatures of around twenty-five degrees are aspired
in summer. The cooling energy gets transported out of the
building via water or brine. The heat exchanger in the ground
can be a deep-ground-sond or a pile-foundation-tube. It is
possible to do free cooling; the only energy demand shows the
pump, which transfers cooling energy to the ground-heat
exchanger.
energy-sond:
The cold contribution in the building can occur by space
cooling systems which need a higher cold water temperature
like ceiling cooling elements or concrete core activation.
The heat transfer medium can be water in frost free depth
otherwise brine. The energy delivery runs between cold
contribution and ground heat exchanger.
The cold source is the deep ground energy. As mentioned
above, ground has got a temperature of around ten degrees in
a certain depth. This cold source is made available via pilefoundation-tubes, so called pile-sond or deep-ground-sonds,
so called energy-sonds.
pile-sond:
Energy sonds are plastic double-tubes which are brought in
ground-boreholes. These boreholes are separately drilled and
they can reach a depth of one hundred meters or deeper with
a diameter of around ten decimetres.
The number of boreholes is according to the cooling energy
demand of the building.
Direct cooling with ground energy source
1/2
The position of energy-piles is different. Local build pilefoundation sond-tubes are fixed in the concrete-reinforcementcage.
The sonds can be situated relative free in the impalement. The
bigger the number of sonds in a pile, the bigger the peak of
power; but thereby the average power rises insignificant.
Energy-sonds and -piles are a relative inexpensive system to
generate heat or cold out of the ground. Where no flowing
ground water is present, a carefully planning and an equated
energy balance between heat-removal and heat-input is very
important. This shows not only simulation-results, also the
experience by realised applications.
The power of energy-sonds and energy-piles is lying between
15 and 80 W/m borehole- or pile-depth. It is a function of the
ground-conditions (wet or dry ground, ground water, material).
A soil analysis has to be done in every case to know the
exactly power of a ground source. The energy yield of ground
energy usage has to be considered, the boreholes and piles
must not be overloaded. That means cooling power and
times should be adapted smart. The energy output can be
between 10 and 80 kWh/ma. As mentioned before, each case
has to be specially considered.
Sources:
ZEN; 1999
Rehau; Raugeo Systemtechnik zur Erdwärmenutzung, 2007
Rehau; Geothermie, 2007
Direct cooling with ground energy source
2/2
Water basin, -wall and -fountain
By a selective positioning of water surfaces in buildings,
respectively building parts, a not insignificant contribution to the
space-cooling can be realised due to the exploitation of the
evaporating heat of water. Concerning to the evaporation of
water, ambient air will be detract evaporating heat and so, airtemperature decreases.
For this kind of cooling water basins (indoor ponds, artificial
creek courses and water landscapes), water walls and indoor
fountains are available and can be integrated aesthetically in
the building.
Volatilizing is a slow evaporating of water, where the
evaporating heat of the environment is detracted.
The amount of evaporated water and required heat from the
ambience is proportional to the difference of the partial
pressure of the unsaturated humid air and the partial pressure
of the water vapour in the interface. Provided that the partial
pressure of the water vapour is bigger than the partial pressure
of the unsaturated humid air.
1/2
The generated cooling power per m² water-surface due to
volatilizing is depending on:
Air humidity [kg/kg]
Interface humidity [kg/kg]
Evaporating heat of water [kJ/kg]
Evaporating amount [kg/m²h]
and
Values out of literature:
Wet-bulb-temperature/ water-surface-temperature [°C ]
Air temperature [°C]
Convective heat transfer between sheet surface and air
[W/m²K] (depending on air velocity)
65…600 W/m² (silent water surface … fountain) [1,2]
[1] Recknagel, H., Sprenger, E., Schramek, E.R.; Taschenbuch für Heizung- und Klimatechnik,
einschließlich Warmwasser- und Kältetechnik, Oldenbourg, München, 1999, 69. Auflage, page 1606
[2] Lichtmeß, M.; Analyse der theoretischen Kühlleistung eines Wasserbeckens in Gebäudenähe,
www.enec.de/Download/STUDY_COOL.pdf; 10.02.2009
2/2
Indoor plants
Indoor plants improve the room indoor environment quality by
temperature decrease and natural air-humidification; out of it a
resulting cooling-function, which is very efficient in summer.
Plants are improving air quality, binding house dust and
eliminating pollutants. Due to this psychologically features they
contribute to human well being in buildings.
Due to evaporating of water on the surface of the plant’s
sheets a certain cooling power is generated. This cooling
power is depending on the volume of evaporating water, air
temperature, velocity and humidity.
The evaporating-amount of plants is directly proportional to the
current illumination-power, so that there are significant
day/night fluctuations. The light demand of plants should be
considered where they get placed (sunny or shady position).
Interesting for office-rooms is the acoustic-absorption function
of indoor plants; sheet surfaces are absorbing, reflecting and
spreading acoustic waves.
Indoor plants
1/2
The evaporating amount [kg/m²h] of
plants is depending upon:
Cooling power per transpiration
active sheet surface is depending
upon:
Type of plant
Season
Difference of air- and sheet-interface-humidity x [g/kg]
Illumination power [lux]
Evaporating amount of the plant [kg/m²h]
Evaporating heat of water r [kJ/kg]
and
Convective heat transfer between sheet surface and air
[W/m²K] (is depending on air velocity)
Difference of air- to sheet-surface-temperature [K]
Value from literature:
“By close planting a cooling power of 16 W/m² due to
evaporating power can result” [1]
Every individual case should be considered especially.
[1] Preisack, E.B., Holzer, P., Rodleitner H.; Neubau Biohof Achleitner, Gebäude aus Stroh & Lehm, Raumklimatisierung mit Hilfe von Pflanzen, Programmlinie Haus der Zukunft des bm:vit; 2002, page 42
Indoor plants
2/2
Daylight illumination
Electrical lighting generates a certain amount of cooling load.
In some buildings it is necessary to active lighting during day,
even when the sun is shining. With so called SolaTubes it is
possible to use daylight instead of electrically generated
illumination. With that device, it is possible to decrease the
consumption of currant for lighting and also the demand of
cooling energy.
Daylight respectively sunlight is collected via a lense at the top
of the roof or at the exterior side of a wall. This lense avoids
over-illumination at midday in summer.
A reflected tube conducts the collected light to a second lense,
which is smoothly spreading the light inside a room. 99.7% of
the light comes through this lens-pipe-lense-system. A further
feature is the UV-blocking function and the lighting power is
dimmable. The light contribution lens integrated can be a
conventional lighting system, so no additional lighting is
necessary. The tube could also be used for ventilation
activities.
In the two following pictures an unlighted bathroom is faced to
a (day)lighted one.
1/2
An extract of features of Solatubes is shown here:
pipe diameter
250 mm
350 mm
lighted area
14 m²
25 m²
maximum length
6
9
Source: http://www.solatube.at/; 20.04.2009
2/2
Fans
An alternative way respectively an additional
application to fulfill the summer comfort criteria within
buildings is to increase the heat removal from human
body with the usage of desk-, ceiling- and fan coilfans instead of cooling the room air with an active
cooling system.
The increased air velocity is resulting in higher heat
dissipation from the human body to the surrounding
air. A further aspect is the increased evaporating rate
of sweat on the skin. With this increased heat
dissipation from the body the felt room temperature is
lower than the air temperature within a room.
Due to the application of ceiling desk-, ceiling- and/or
fan coilfans it is possible to generate a partly
summer comfort. The operation of active cooling
systems could be avoided totally respectively the
operation time can be reduced significantly.
Generally, the selection and positioning of fans and
the higher air velocity have to be selected under the
requirements of the comfort criteria of P. Ole Fanger.
Fans
1/1

Deliverable 5.1 Report on Available Products and Passive

Transcrição

Documentos relacionados

Data sheet

Ranking Configurations of Shading Devices by Its

Solar Systems catalogue-ENG

CelCulture

evaluation of estimated radiation solar data for using in apsim/oryza

WASHING AND RINSING MACHINE LAboRAtoRy SAMpLE

ub inox solar 200 erp

estimation of hourly global radiation at campina grande

MR1S - Infratemp

instruction manual

rehva Journal RJ1402 - Ventilation Systems and Equipments

Pair-Copulas Modeling in Finance

UB INOX 80-120-200 ErP UB INOX 80-120-200 ErP UB

Microwaves are moving beyond organic synthesis, but there is still

AVIO 24 kW

VICTRIX PRO 35 - 55 2 ErP

Financial innovation and bank behavior