NATURAL VENTILATION SYSTEMThe Complete Solution
NATURAL VENT 2
FEB 2010
PUBLICATION
Mistrale (Cooling Katabatic Wind)Natural ventilation, unlike mechanical fan forced
ventilation, simply uses the naturally occurring
pressure differential forces of air movement, wind
and buoyancy to deliver a steady supply of fresh air
for building ventilation and space cooling.
In an environment where energy conservation is
at a premium this sounds ideal�and it is! Naturally
ventilating a building actually offers the best of both
worlds combining little or no energy consumption with
low capital costs, whilst still providing adequate fresh
air and comfort temperature conditions throughout the
year.
With plant room also eliminated, services space
minimised and lower servicing/maintenance costs
Natural Ventilation now makes for one the most
practical choices of the day.
Modern buildings with their low u values and high
heat gains typically have a high cooling requirement.
The climate in the UK and many parts of central
through Northern Europe is perfectly suited for
Natural Ventilation applications with low extremes
of temperature providing an ample supply of fresh
cooling air even in a typical summer.
Natural Ventilation strategies are founded on two
basic operational strategies and essentially comprise
either of wind driven systems or a buoyancy (stack
effect) system. The Gilberts Mistrale Natural
Ventilation range embraces both of these
philosophies.
In some locations and building designs wind alone
can be used as the principal driving force.
In wind driven systems the air on the wind ward side
of the building creates a positive pressure with
corresponding negative pressure generated on the
leeward side. Using this effect air can be easily drawn
through the building. Although wind driven systems
can be effective, building design, orientation and
location factors are important here for a successful
result.
Although helpful, Natural ventilation systems
do not need wind to operate satisfactorily.
More effective strategies employ alternative buoyancy
and stack effects instead to provide the ventilation
base. Instead of wind pressure a vertical stack or
shaft in the building can be utilised to allow warmer
air to migrate and rise through the building to high
level outlets whilst drawing fresh cool air in from low
level. Stack ventilation does not rely on the wind at all
and, because it does not rely on the pressure or
direction of the wind either, offers greater reliability as
well as more flexibility on the placement and location
of the air intakes.
Gilberts Natural Ventilation engineers are on hand
to discuss whether wind driven, stack driven or,
in more challenging areas, consideration of a mixed
mode system that includes mechanical ventilation, is
the most appropriate strategy for your project.
Stack Driven
Natural Ventilation Strategies
Wind Driven
Wind wardCool fresh
air in
Cool fresh
air in
Warm stale
air rises
Warm stale
air out
Warm stale
air out + VE
pressure
Cool
fresh
air in
Stale
air
out
- VE
pressure
Lee ward
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Introduction
Mistrale system strategies
Mistrale Model A
Mistrale Model B
Mistrale Model C
Mistrale Model D
Mistrale Model E
Mistrale Model F
Mistrale Natural Ventilation Components
Intake Louvres
Volume Control Damper
Heating or Cooling Coil
Fascia Grilles
Roof Top Penthouse Turret Louvres
Type 1 - Exhaust Turret Terminal
Type 2 - Exhaust Turret Terminal with Mounting Sleeve
Type 3 - Exhaust Terminal with Mounting Sleeve and
Damper
Type 4 - Wind Driven Terminal
Type 5 - Wind Driven Terminal with Air Distribution Plenum
Penthouse Louvre Performance Data
Acoustic Silencer
Acoustic Information
Mistrale Natural Ventilation Control
Control Strategy
Control Display Options
System Performance
Ordering Specifications
4
Low Level
Low level floor installations, whether in glazing or the wall
structure itself, is the most popular installation location
providing for optimum air flow and comfort
conditions. Cooling outside air will be
drawn through the assembly at low
room level ventilating through higher
level wall grille and damper
assemblies into the stack.
Since the airflows are usually
unrestricted this typically
maximises the air movement
efficiency.
Under Floor
An under floor ventilation arrangement gives the opportunity
to keep walls and window areas free or can simply be used
for areas where external wall areas may not be available.
A louvre intake and damper arrangement draws air into
the floor void and distributes this into the room at floor
level through standard design floor grilles. The cool
fresh denser air displaces the lighter warm air
upwards where it is extracted through high level wall
grille and damper assemblies into the stack. Under
floor systems which have fewer depth/thickness
restrictions also give greater opportunity for acoustic
insulation in areas where external noise might
be a problem.
CeilingSimilar to an under floor installation a ceiling displacement
arrangement gives the opportunity to keep walls and window
areas free and can be used for areas where wall space may
not be available. Cooling air is drawn in through a louvre and
damper arrangement for distribution through traditional
ceiling diffuser air outlets or even laminar flow outlets.
The cooler air sinks displacing the warmer stale air which
can then be drawn out into the stack through higher level
wall grille and damper arrays. Because natural
ventilation relies mostly on a buoyancy effect
ceiling systems are inherently less efficient
unless they are also wind driven. However
ceiling systems again have fewer
depth/thickness restrictions and so also
give greater opportunity for acoustic
insulation in areas where external noise
might be a problem.
Mistrale System Strategies
Natural ventilation systems comprise of a number of key
components. Although windows can be used for ventilation the
Gilberts Mistrale system does not feature a window based
strategy. Window based systems can be simple but are also
inherently disadvantaged. With natural ventilation systems often
using low overnight temperatures for cooling, opening windows
are usually not desirable from a security aspect. Other issues
such as noise penetration and water ingress are also difficult to
avoid and window motorisation can also compromise aesthetics.
Windows may also not offer the fine levels of control and
balance required for a modern ventilation system. For this
reason Gilberts Mistrale System focuses on using optimum,
measured performance components that include a secure intake
louvre, a fully controllable insulated volume control damper, a
heating or cooling coil, a covering fascia grille and
intake/exhaust penthouse roof turrets.
A typical Mistrale natural ventilation assembly comprises of an
intake louvre, air regulating damper and fascia grille. Installation
options are varied with the opportunity for window, low level
floor, under floor or even over ceiling installation. This installation
strategy will affect your detailed choice of louvre, damper and
fascia components.
5
Floor Swirl DisplacementFloor outlet swirl diffusers allow fresh natural
ventilation air to enter the space from the floor
void. The cool fresh air will displace the warmer
stale air which can evacuate through the transfer
grilles into the stack. Standard linear bar type floor
grilles which have a lower pressure resistance, can
also be utilised.
Ceiling Laminar Flow DiffusersCeiling laminar flow diffusers allow natural
ventilation air to enter the space from the ceiling
void. The cool fresh air will intermix and sink
displacing the warmer stale air which can evacuate
though the transfer grille into the stack.
TransferThe transfer grille is usually
fitted at high level within the
conditioned space.
This provides a pathway for
the warm stale exhaust air to
rise and pass from the room
space into the ventilation stack.
Exhaust Wall OutletHigh level exhaust outlets
offer an alternative to roof top
turrets and allow the warm
stale air entering the stack
to rise and ventilate to the
outside.
Penthouse Exhaust TurretRoof level exhaust turrets are the popular
means to allow the warm stale air in the stack
to ventilate. These turrets can also be set up
for use as combined fresh air intake and
exhaust outlets when used in wind driven
systems.
Stack
Mistrale Natural Ventilation
Mistrale Model AIntake unit with Heating or Heating/Cooling
Coil
Model A is the most popular natural ventilation unit choice
and is primarily intended as a supply/intake unit for low
level mounting installation. A low level model provides for
optimum air flow and comfort conditions as cooling outside
air will be drawn through the assembly at low room level
with the warmer air then ventilating through higher level
wall grille and damper assemblies (See Model F) into the
stack. Units are typically fitted with a coil to allow for initial
heating of the air, when required, before entering the room.
Standard arrangement (as illustrated) comprises
• External Louvre - Standard high efficiency
weather louvre with choice of flange, channel
or window beading fixing frame options.
• Insulated Volume Control Damper - Manual
or Motor control.
• Heating/Cooling Coil.
• Decorative Fascia Grille - Standard routed or perforated
face pattern fascia panel in standard or low surface
temperature format.
Size Range
Effective damper size.
Width 300, 800 or 1300mm
Height 206, 406 or 606mm
Structural opening sizes
Damper width + 260mm
Damper height + 110mm
Finish
Both the external louvre and the fascia grille finished to
standard BS/RAL colours.
Our Mistrale Natural Ventilation System has been developed
with maximum project flexibility in mind. Different buildings
and structural designs combined with the building location
and design purpose present a wide variety of factors which
can affect system selection. As standard we offer 6 model
configurations (Model A to Model F) but the ability to also
pick and mix the various components of Mistrale enables us
to adapt our product for a multitude of different installations.
Louvre Glazing
Bead
Channel Louvre Flanged Louvre
Dim ‘A’ WG/100 - 121mm
WH/75 - 121mm
WG/75 - 72mm
WG/38 - 50mm
Fixing Options
5mm
Enlarged
detail
Damper
drive
position
(electric
actuator
illustrated)
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Mistrale Model BIntake unit with Heating Coil
Model B is a further variation on Model A and is primarily
intended for installation above the floor level at low or mid
room heights whilst still providing for optimum air flow and
comfort conditions.
Cooling outside air will be drawn through the assembly
with the warmer air ventilating through higher level wall
grille and damper assemblies out into the stack. Units are
fitted with a coil to allow for initial heating or cooling of the
air before entering the room.
A typical arrangement (as illustration) comprises
• External Louvre - Standard high efficiency weather
louvre with choice of flange, channel or window
beading fixing frame options.
• Insulated Volume Control Damper - Manual
or Motor control.
• Heating/Cooling Coil.
• Decorative Fascia Grille - Standard routed or perforated
face pattern fascia panel or any of our other grille
designs such as eggcrate or linear bar type grille.
Size Range
Effective damper size (internal blade area).
Width - 300 up to 2000 in 100mm increments
Height - 206 up to1006 in 100mm increments
Structural opening sizes
Damper width +260mm
Damper height +110mm
External LouvreBoth the external louvre and the fascia grille
finished to standard BS/RAL colour.
Louvre Glazing
Bead
Channel Louvre Flanged Louvre
Fixing Options
Dim ‘A’ WG/100 - 121mm
WH/75 - 121mm
WG/75 - 72mm
WG/38 - 50mm
Mistrale Natural Ventilation
Mistrale Model CConcealed Intake unit with Heating Coil
Model C is an alternative to the popular Model A and is
primarily intended as a supply/intake unit for installation
above the ceiling or below floor level. Cooling outside air
will be drawn through the assembly and delivered to the
occupied zone via standard ceiling or floor diffusers.
Although slightly less efficient in terms of the air
movement path this model does have the distinct
advantage of having more space (due to the physical
location) which also then allows installation of silencers to
attenuate incoming noise. This potentially makes the unit
a better selection in more urban city environments where
noise ingress might be an issue.
Standard arrangement (as illustration) comprises
• External Louvre - Standard high efficiency
weather louvre with choice of flange, or channel
fixing frame options.
• Insulated Volume Control Damper - Manual
or Motor control.
• Heating/Cooling Coil.
• Acoustic Silencer - Optional silencer in single
or double bank assembly.
Size Range
Effective damper size (internal blade area).
Width - 300 up to 2000 in 100mm increments
Height - 206 up to1006 in 100mm increments
Structural opening sizes
Damper width +260mm
Damper height +110mm
External LouvreExternal louvre finished to standard BS/RAL colours.
Louvre Glazing
Bead
Channel Louvre Flanged Louvre
Fixing Options
Dim ‘A’ WG/100 - 121mm
WH/75 - 121mm
WG/75 - 72mm
WG/38 - 50mm
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Model DIntake unit without Heating Coil
Similar to Model C, Model D is primarily intended for
installation above the floor level at low or mid room height
and provides for optimum air flow and comfort conditions.
Cooling outside air will be drawn through the assembly
with the warmer air ventilating through higher level wall
grille and damper assemblies into the stack. In Model D
however units are designed for installation where an
independent heating system is employed and so are not
fitted with integral heating/cooling coils.
Standard arrangement (as illustration) comprises
• External Louvre - Standard high efficiency weather
louvre with choice of flange, channel or window
beading fixing frame options.
• Insulated Volume Control Damper - Manual or Motor
control.
• Decorative Fascia Grille - Numerous type of fascia
grilles can be fitted.
Size Range
Effective damper size (internal blade area).
Width - 300 up to 2000 in 100mm increments
Height - 206 up to1006 in 100mm increments
Structural opening sizes
Damper width +260mm
Damper height +110mm
External LouvreBoth the external louvre and the fascia grille
finished to standard BS/RAL colours.
Louvre glazing
bead
Channel Louvre Flanged Louvre
Fixing Options
Dim ‘A’ WG/100 - 121mm
WH/75 - 121mm
WG/75 - 72mm
WG/38 - 50mm
Mistrale Natural Ventilation
Model EExhaust unit without Heating Coil
Model E is primarily intended for installation at high wall or
stack level to provide an external outlet for the warm stale
exhaust air. Depending on the functional area units may
require an insulated damper or non insulated blade
damper. With no air tempering requirements in these
areas no heating/cooling coil options are available.
A typical arrangement (as illustration) comprises
• External Louvre - Standard high efficiency weather
louvre with choice of flange, channel or window
beading fixing frame options.
• Volume Control Damper - Volume control damper
may be insulated or un-insulated and with Manual
or Motor control.
Size Range
Effective damper size (internal blade area).
Width - 300 up to 2000 in 100mm increments.
Height - 206 up to1006 in 100mm increments.
Structural opening sizes
Damper width +200mm
Damper height +110mm
External LouvreBoth the external louvre and the fascia
grille finished to standard BS/RAL colours.
Louvre Glazing
Bead
Channel Louvre Flanged Louvre
Fixing Options
Dim ‘A’ WG/100 - 121mm
WH/75 - 121mm
WG/75 - 72mm
WG/38 - 50mm
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Model FTransfer Exhaust unit without Heating Coil
Model F is primarily intended for installation at high room
level for exhaust or transfer application. Stale warmer air
from the room will be drawn through the assembly into the
stack. With no air tempering requirements units are not
fitted with heating coils.
Standard arrangement (as illustration) comprises
• Volume Control Damper - Insulated or non insulated
and with either Manual or Motorised control
• Decorative Fascia Grille - Numerous type of fascia
grilles can be fitted to one or both damper sides.
Size Range
Effective damper size (internal blade area).
Width - 300 up to 2000 in 100mm increments
Height - 206 up to1006 in 100mm increments
Structural opening sizes
Damper width +260mm
Damper height +110mm
External LouvreFascia grille finished to standard BS/RAL colours.
Mistrale Natural VentilationComponents Depending on the ventilation strategy and the preferred
location the installation may require a mix and match of
various standard Mistrale components
Intake Louvre
Gilberts intake louvres provide a high weather efficiency
design with only a standard single louvre bank arrangement.
This slender robust but weather efficient and patented
design offers a much lower pressure resistance than
conventional double bank weather designs. This allows us
to use smaller louvre areas for any given air requirement
or in effect provide more air, size for size, as compared to
competitive designs ensuring maximum design cost
efficiency. Structurally strong they can be fitted in to
either window openings or walls.
Air Volume Control Damper
Close control is one of the key factors for an effective
natural ventilation system with the ability to regulate airflows
accurately to meet occupancy levels and temperature
requirements vital. The patented Gilberts volume control
damper is a unique design that is fully adjustable ranging
from full open to full closed. When closed the damper has
an extremely low leakage rate that prevents draughts and
inefficiencies.
The casing is manufactured from low conductivity material
which prevents any cold bridge effect allowing total isolation
from internal to external areas. Furthermore the damper
comprises a double insulated blade arrangement which
means that the damper has a very low ‘U’ value (when
closed) of 1.6 w/m2 ˚C, which is as good as a sealed double
glazed window unit This prevents wasteful energy losses
or gains. The insulation also provides a secondary acoustic
reduction effect.
Heating or Cooling Coil
Heating coils add a wide degree of flexibility to the system
providing not only for tempering of the air but also for some
heating capacity to be employed within the design. When
used to support heating the system air movement is actually
accelerated, resulting in a faster and more efficient heating
process as compared to pure radiator based systems alone.
Alternatively cooling coils or dual purpose heating/cooling
coils can also be fitted to allow full control over air intake
temperatures.
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Performance Assured
Specific designs will use a combination of some or all
of these components along with a bespoke controls
strategy using room temperature and/or CO2 sensors
to deliver comfort conditions. Incorporated in 1960
Gilberts have been meeting the challenges of air
distribution for nearly 50 years and have all the tools,
techniques and expertise available to make your
project a success. All of our products are designed
and tested in our own air movement laboratory and
supported with airflow CFD modelling
Fascia Grilles
Gilberts manufacture a wide variety of fascia grilles
and diffusers for floor wall or ceiling mounting.
With a wide range of both standard and bespoke tested
designs we can provide grille design solutions to meet
the requirements of the most demanding projects.
Decoratively designed punched panels can also be used
on internal faces which can be fitted with insulation to
maintain a low surface temperature where required.
Intake/Exhaust Penthouse Turret
Louvre
The Gilberts intake/exhaust turret can be specifically
manufactured in a wide variety of configurations to
suit the system design parameters. The turrets can
be designed to suit wind driven systems or stack effect
with internal partitions and dampers providing for full
and accurate air movement control.
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Gilberts Natural Ventilation intake louvres provide a high
weather efficiency design with only a standard single louvre
bank arrangement. Under driving wind and rain conventional
single bank louvres will allow some degree of water ingress.
With motorised dampers (and possibly coils) behind the louvre
this is undesirable and for this reason Gilberts Natural
Ventilation louvres are all of a high efficiency design as
standard.
Our slender weather efficient, patented louvre design is not only
narrow but also offers a much lower pressure resistance than
conventional double bank high weather protection designs.
This allows us to use smaller louvre areas for any given air
requirement or, in effect, simply provide more air, size for size as
compared to competitive designs. A key benefit here is that this
reduces the size requirements not only for the louvre but also
for expensive associated components like dampers and
heating/cooling coils to ensure maximum design cost efficiency.
Manufactured from extruded aluminium our louvres are
structurally very strong and can be fitted into either the
window openings or into the walls.
All louvres are fitted with bird guard screens as standard
with insect screens and weather cills also optionally available.
A durable polyester powder finish to any BS/RAL colour also
allows architectural choice to blend or contrast with the building
structure as required
Intake Louvres
Dim
ensi
on o
ver F
lang
es =
Lis
t Hei
ght +
45 (+
1m
m)
_
List
Wid
th o
r Hei
ght _
10m
m
mm57hctiP
Stru
ctur
al O
peni
ng =
Lis
t Wid
th o
r Hei
ght
121mm
Type NV-WHF/75
- Flange Face Border
Type NV-WHC/75
- Channel Frame Border
Dim
ensi
on o
ver C
hann
el =
Lis
t Hei
ght _
10 ( +
1m
m)
_
m m 5 7 h c t i P
Stru
ctur
al O
peni
ng =
Lis
t Wid
th o
r Hei
ght
121mm
Efficiency Graph Water Repellent & Drainage FeaturesTesting in accordance with European Standard EN13030 for
weather louvre Performance shows our WH unit be 99.5%
effective in screening/exhaust applications and 99% effective
even with face velocities of up to 1m/sec (rated at class ‘A’).
The performance graphs below illustrate effectiveness under
differing weathering parameters.
All testing was conducted in accordance with European
Standard EN 13030 ie: simulated conditions of 13m/sec (30mph)
wind speed with heavy rain. Even at extremes of selection the
unit offers excellent weather protection.
Similarly the pressure loss graph clearly indicates the minimal
pressure losses incurred by the WH design. Performance at
this level ranks the units alongside the very best in performance
louvres.
All Natural Ventilation assemblies are normally provided as
standard with a high efficiency weather louvre on the outside.
These units have been classified to the current weather louvre
test standard reference BS EN 13030 and offer a high degree
of water protection.
If however a small amount of water does pass through the
weather louvre blades, provision has been built in to the Natural
Ventilation design which will cater for collection and the drainage
of this water back to the outside via the lower section of the
assembly.
This design is similar to the design used on some double glazed
units and prevents water lodging in any part of the assembly.
It is however recommended that the units are cleaned on a
regular basis with all drain channels checked.
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E C N A T S I S E R W O L F R I A
LOU
VRE
PRES
SUR
E D
RO
P Pa
m R E P E T A R N O I T A L I T N E V 2 E R V U O L F O m ( A E R A E C A F 3 m / s / 2 )
M R E P E T A R N O I T A L I T N E V 2 AE R A E C A F E R V U O L m ( 3 m / s / 2 )
S T S E T L L A N I D E E P S D N I W s / m 3 1 ) A : E T O N m / m m 5 7 ) B 2 E C A F E R V U O L O T N O Y A R P S R E T A W
S T S E T L L A N I
0 5 0
0 6
0 7
0 8
0 9
0 0 1
5 . 0 0 . 1 5 . 1 0 . 2
EFFE
CTI
VEN
ESS
% Y C N E I C I F F E R E H T A E W
0 8 0 7 0 6 0 5 0 4
0 3
0 2
0 1
0 . 3 0 . 2 0 . 1 5 . 0
5
2
2 e l b a T 1 e l b a T
ing parameters.
v
c Pressure/Volume Graph Effectiveness/Volume Flow
Graph
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Volume Control Damper
Controllability is one of the essential key factors for an effective
natural ventilation system with the ability to regulate airflows
accurately to meet occupancy levels and temperature
requirements very important.
The patented Gilberts volume control damper is a unique design
that is fully adjustable from full open to full closed. When closed
the damper has an extremely low leakage rate that prevents
all draughts and system inefficiencies.
The casing is manufactured from low conductivity material
which prevents any cold bridge effect allowing total isolation
from internal to external areas. Furthermore the damper
comprises a double insulated blade arrangement which means
that the damper has a very low u value (when closed) of 1.6
w/m2 °C, which is as good as a sealed double glazed unit
preventing wasteful energy heat loss or gain. The insulation
also provides a secondary acoustic reduction effect. For less
sensitive areas, such as for exhaust, damper units can also be
specified without insulation without affecting leakage rates
The damper will typically be motor actuator controlled but can
also be manually operated if required.
In order to establish the increase in resistance that will apply
as the damper closes a graph showing pressure drop against
percentage open is detailed on page 17.
Current Building Regulation Requirement
Graph No.2 illustrates current building regulations maximum
leakage rate of 10m3/H/m2 and the actual leakage rate of a 1m2
damper.
The current damper design is approximately 40% below these
regulation requirements.
Casing Leakage Rating
Testing was conducted in accordance with BS/EN 1751 in order
to establish the casing leakage rate for a 1m2 damper. Following
these tests it was established that the unit conformed with Class
C which is also equivalent to Ductwork DW 144 specifications
Torque Rating
Tests were conducted on a 1m2 damper to establish the drive
torque requirement under operating conditions.
It was confirmed that 4 Nm was required to operate the
damper rising to 12 Nm to compress the seals for total closure.
Minimum recommended motor torque for this size of
unit = 20nm. For reduced damper sizes the following
would be recommended:- 2Nm reduction for every
100 mm reduction in damper height.
Pressure Leakage
In order to meet current building regulations graph details
are provided to illustrate the air leakage rates against various
pressure differentials (Graph Ref. 2)
The data has been derived from a 1 m2 damper tested in
accordance with BS EN 1751 and indicates the maximum
leakage now acceptable under current building regulations
against actual leakage rates at 50 Pa differential pressure.
Manual Control Motor ControlDamper Drive Options
Ref 1 - Manual Handle Operation
Ref 2 - Manual Teleflex Operation
Ref 3 - (3 Point) SM24A Actuator AC 24v/DC 24v
Ref 4 - (3 Point) SM24A-S Actuator AC 24v/DC 24v
Ref 5 - (3 Point) SM230A Actuator AC 100~240v
Ref 6- (3 Point)SM230A-S Actuator AC 100v/DC 240v
Ref 7 - (Modulating) SM24A-SR Actuator AC 24v/DC 24v
Ref 8 - (Modulating) SM24A-M Actuator AC 24v/DC 24v
Ref 9 - (Modulating) SM230A-SR Actuator AC 100~240v
17
Unit make-up Air space
6 10 12 16 20
4 mm/air 4 mm 3.18 2.87 2.78 2.68 2.67
4 mm/argon/4 mm 2.93 2.69 2.62 2.56 2.55
4 mm/air/4 mm k 2.59 2.07 1.91 1.73 1.70
4 mm/argon/4 mm k 2.18 1.73 1.60 1.5 1.48
4 mm/air/4 mm/air/4 mm 2.25 1.95 1.87 1.78 1.77
‘U’ values in W/m2K for vertical glazing subject to normal
exposure conditions according to BS 6993 Part 1
Thermal InsulationThermal transmittance testing was carried out in accordance
with the requirements laid down in BS EN 1751 to determine
the amount of heat that would be transferred through a 1 m2
damper assembly. Testing was carried out with the blades
insulated and also without insulation with the following results:-
Mill finish damper assembly after a minimum test period of
4 hours.
‘U’ value (Wm2/K) = 1.99
With damper blades insulated on both sides with 6.0 mm
of pyrosorb insulation material.
‘U’ value (Wm2/K) = 1.52
This compares favourably with values for a typical double
glazed panel.
0.01
0.1
1.0
10
2
3
4
5 6 7 8 9
2
3
4
6 5
7 8 9
3
2
4
5 6 7
9 8
0.1
10
100
1000
2
3
4
5 6 7 8 9
2
3
4
6 5
7 8 9
3
2
4
5 6 7
9 8
1 100 1000 1010 0.1 4 3 2 9 8 7 6 5 4 3 2 9 8 7 6 5 7 2 6 5 4 3 9 8 7 2 6 5 4 3 9 8
Volume L/S/m²
Pre
ssur
e (P
a) m
²
Volume L/S/m²
Pre
ssur
e (P
a) m
²
Full open
75% open
Act
ual l
eaka
ge a
t 50
PA
1.7 l/s @ 50Pa = 6.1m3/H/m2 2.77 l/s = 10m3/H/m2
Max
Allo
wed
leak
age
at 5
0 PA
25% open
50% open
Pressure Drop / Volume Graph (based on 1m2 High efficiency damper)
Open (Ref. 1 Various open positions) Full Closed (Ref. 2 Leakage)
Gra
ph 1
Gra
ph 2
Heating or Cooling Coil
The addition of a heating coil allows an extra degree of
control to your natural ventilation system.
Although we have a year round ventilation requirement
there are many days when outside air temperatures may
simply be too cold for direct input. In these instance in-line
heating coils can be used to temper the incoming air
to allow continuous ventilation rates without compromising
temperature control. Heating coils also add a wider degree
of flexibility to the system allowing an amount of space
space heating to be employed within the overall Ventilation
design. When used to support the heating system, air
movement actually results in a faster and more efficient
heating process as compared to pure radiator based
systems alone.
Type VN-H - Heating Coil
Type VN-HC - Combined Heating and Cooling Coil
A dual 4 pipe combined heating and cooling system is
also optionally available to provide summer cooling should
a suitable supply of chilled water be available. Since the
units require relatively high chilled water temperatures, in
order to avoid supply air condensing on the coil, they are
particularly suitable for including in a chilled ceiling water
circuit.
Coil Connections
The heating coils terminate with industry standard 15mm
copper connections. If combined heating/cooling coils are
fitted then separate flow and return connections are
provided for both the heating and cooling sections.
Coil Capacities
Heating and cooling capacities can be calculated
from the graphs on page 19.
Overall Coil Width = Effective Damper Size 75mm
Overall Coil Width = Effective Damper Size 75mm
Ove
rall
Coi
l Hei
ght =
Effe
ctiv
e D
ampe
r Siz
eO
vera
ll C
oil H
eigh
t = E
ffect
ive
Dam
per S
ize
Combined Heating and Cooling Coil
Heating Coil (only)
18
19
0 0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
1 2 3 4 Duty (kW)
Water flowrate against temperature drop (heating)
Wat
er fl
owra
te (l
itres
/s)
Hea
t out
put (
kW)
Coo
ling
outp
ut (k
W)
5 6 7 8 9 10 11 12
5˚C 10˚C 15˚C 20˚C 25˚C
Heat output against temperature difference
0
1
2
3
4
5
6
7
8
9
10
Mean water - outside air temperature (°C)
Cooling output against temperature difference
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Outside air - mean water temperature (°C)
per m2 coil face
per m2 coil face
0
0.05
0.1
0.15
0 0.5 1 1.5 2 2.5 3
2˚C
0.2
0.25
0.3
0.35
Duty (kW)
Water flowrate against water temperature rise (cooling)
Wat
er fl
owra
te (l
itres
/s)
0
0
5
10
15
20
25
30
35
40
10
20
0.30
0
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35
0.1 0.2 0.3 0.4 0.5 0.6
40
50
60
70
Water flowrate (litres/s)
Water flowrate (litres/s)
Water pressure drop against flowrate (heating)
Water pressure drop against flowrate (cooling)
Wat
er p
ress
ure
drop
(kP
a)
Wat
er p
ress
ure
drop
(kP
a)
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
Face velocity (m/s)
Coil airside pressure drop
pres
sure
dro
p (P
a)
4˚C 6˚C 8˚C
Htg Coil Htg/Clg coil
20
Fascia Grilles Gilberts manufacture a wide variety of fascia grilles and
diffusers for floor wall or ceiling mounting. With a wide
range of both standard and bespoke tested designs
we can provide grille design solutions to meet the
requirements of the most demanding projects.
Decoratively designed punched steel panels can be used
on internal faces of low level wall units and these can be
fitted with insulation to maintain a low surface temperature
where required. As standard we offer the routed face
panel (flat or curved), a fixed blade linear bar grille with
blades angled at 0, 15 or 40 degrees and an eggcrate
pattern.
All grilles are manufactured from aluminium or steel and
can be finished in a durable polyester powder finish to any
BS/RAL colour.
Type VN/RP-1
Type VN/KO
Type VN/SK
Type References
VN/RP-1 Curved Routed Panel (Model A)
VN/RP-2 Flat Routed Panel (Models B, C, D & F)
VN/RP-3 Perforated Face Panel (Models B, C, D & F)
VN/KO Bar Grille (Models B, C, D & F)
VN/K15 Bar Grille (Models B, C, D & F)
VN/K40 Bar Grille (Models B, C, D & F)
VN/SKO Bar Grille (Models B, C, D & F)
VN/GE Eggcrate Core Type (Models B, C, D & F)
Type VN/RP-1 Type VN/RP-3
Type VN/KO Type VN/GE
Type VN/RP-3
Type VN/GE
Roof Top Penthouse Louvre
The Gilberts intake/exhaust penthouse turret
can be manufactured in a wide variety of size
and shape configurations to suit the system
design or aesthetic parameters. The turrets
can be designed to suit wind driven systems
or stack effect with internal partitions and
dampers providing for full and accurate air
control. All penthouse units are of our
patented high weather efficiency design as
standard to eliminate weather ingress and
can be fitted on to both flat and pitched roofs.
Design styles are flexible with traditional
square designs most popular and with a
variety of roof top options. Special or
bespoke roof tops can also be included to
complement or contrast with your building
design.
A durable polyester powder finish to any
BS/RAL colour allows a free matching
architectural choice. Bird guards screens are
fitted to the rear as standard
with insect screens also optionally available.
21
22
Penthouse Turret Options
Type 1 - Exhaust Turret Terminal
The Type 1 exhaust turret provides an attractive and
efficient means for rooftop exhaust of natural ventilation
air. Warm air rising up through the building can be easily
vented through standard rooftop exhaust terminals.
Manufactured with high weather efficiency blades the units
are designed to provide maximum weather protection to
prevent problematic ingress of rain. Standard blade pitch
is 75mm with a steep 45 degree blade angle.
Units can also be provided with eliminator sections behind
the standard blade profile to offer increased water
protection at high wind velocities.
TYPE VNT/1 - Standard Terminal
TYPE VNT/2 - Terminal with eliminator
The table below provides dimensions and weights for both
types of assemblies..
Nominal
Width ‘W’
(internal duct
width)
400
600
800
1000
1200
1400
400
600
800
1000
1200
1400
Eliminator
N
N
N
N
N
N
Y
Y
Y
Y
Y
Y
Unit
VNT/1
VNT/2
Nominal
Length ‘L’
(internal duct
width)
400
600
800
1000
1200
1400
400
600
800
1000
1200
1400
Height ‘H’
(Standard)
467
568
670
847
949
1051
467
568
670
847
949
1044
Weight
(kg)
22
35
51
79
104
134
26
42
62
95
125
172
Number of
blades
3
4
5
7
8
9
3
4
5
7
8
10
Standard roof illustrated above
Section showing
internal
eliminator array
on Type VNT/2
Curb Type - B1
23
Type 3 - Exhaust Terminal with Mounting Sleeve
and Damper
The Type 3 exhaust turret provides a means for rooftop
exhaust of natural ventilation air and includes a purpose
factory built mounting sleeve and volume control damper.
The louvre enjoys the exact same specification as the
Type 2 Terminal.
Type 3 however is a fully self contained terminal that does
not rely on further ducting or separate volume control.
It includes a motorised volume control damper at the base
which allows the unit to fully open, close or modulate
as demand requires. The damper is mounted on the sleeve
outlet and can be linked in to the natural ventilation building
management system. The damper (see full details on page
16) is our patented fully insulated design which again
provides a full thermal barrier with a U value of 1.6w/m2˚C.
Standard fixing is via kerb mounting flange and bird guards
are also fitted as standard with insect screens optionally
available.
Type 2 - Exhaust Turret Terminal with
Mounting Sleeve
The Type 2 exhaust turret provides a means for rooftop
exhaust of natural ventilation air and includes a purpose
factory built mounting sleeve. The louvre features the exact
same specification as the Type 1 detailed on page 22.
For Type 2 however the additional duct sleeve provides a
safe effective means to fit the louvre to the roof structure
and also allows for convenient ducting off below the roof
level. The sleeve is available in both an insulated and non
insulated format. The insulated version is standard with the
sleeve design incorporating a phenolic thermal foam barrier
which prevents transfer of heat/cooling energy from inside
to outside. This thermal barrier has a U value of 1.6w/m2˚C.
Standard fixing is via a kerb mounting flange and bird
guard screens are also fitted as standard to the rear.
Insect screens are available on request
Curb Type - B4
24
Type 5 – Wind Driven Terminal with Air Distribution
Plenum
The Type 5 provides a wind powered terminal that features the
exact same specification as the Type 4 but also includes a 4 way
distribution plenum at the base.
The turret is fitted to the roof using our standard installation
sleeve with built in thermal barrier. This sleeve terminates with a
motorised volume control damper which allows the unit to fully
open, close or modulate as demand requires. The damper is
mounted on the sleeve outlet and can be linked in to the natural
ventilation building management system. The damper (see
details on page 16) is our patented fully insulated design which
again provides a full thermal barrier with a U value of 1.6w/m2˚C.
The 4 way plenum fitted at the base allows for fitting of a variety
air grilles and diffusers.
Type 4 – Wind Driven Terminal
As well as Natural Ventilation Exhaust turrets we are able
to offer a complete range of wind powered terminals. Wind
powered systems operate somewhat differently than stack
effect system and, as explained on page 2, they rely on the
wind driving cool fresh air down into the building with the
warmer air exhausting both through buoyancy and
incoming air pressure displacement. In order to create this
feature the turret is fitted with specialised splitters that
provide four separate air paths. Air is driven down into the
occupied zone through one or more of the airways and is
then exhausted through the remaining airways. The wind
direction will determine which airways are used at any
particular time.
The turret is fitted to the roof using our standard installation
sleeve with built in thermal barrier. This sleeve terminates
with a motorised volume control damper which allows the
unit to fully open, close or modulate as demand requires.
The damper is mounted on the sleeve outlet and can be
linked in to the natural ventilation building management
system. The damper (see details on page 16) is our
patented fully insulated design which provides a full thermal
barrier and a U value of 1.6w/m2˚C.
25
1
2
3
9 8 7 6 5 4 3 2
4
5 6 7 8 9
2
3
4
7 6 5 4 3 2 1 9 8 1
2
3
4
5 6 7 8
1 9
2
3
4
6 5
7 8 9
3
2
4
5
1
6 7
9 8
1000
100
100 1000
10
4 3 2 1 9 8 7 6 5
6 5
7 8 9 1
3
2
4
5
7 2 6 5 4 3 1 9 8
6 7
9 8
1
Volume L/S
Pre
ssur
e (P
a)
1
2
3
9 8 7 6 5 4 3 2
4
5 6 7 8 9
2
3
4
7 6 5 4 3 2 1 9 8 1
2
3
4
5 6 7 8
1 9
2
3
4
6 5
7 8 9
3
2
4
5
1
6 7
9 8
4 3 2 1 9 8 7 6 5
6 5
7 8 9 1
3
2
4
5
7 2 6 5 4 3 1 9 8
6 7
9 8
1
Volume L/S per Sq m
Pre
ssur
e (P
a)
100 1000
1000
100
10
Pressure Drop Volume Graphs
Blades at 45° Blades at 45° with eliminator
Airflow Diagrams
Intake or Exhaust Turret
Types 1, 2, & 3 Wind Driven Terminals Types 4 & 5
Sizing And Selection Charts
The following data has been obtained from actual
tests of penthouse turret assemblies.
Graphs A & B represent pressure drops associated
with various volume flow rates as taken from a
1 cubic metre area penthouse.
With four sides this equates to an active louvre face
area of 4 sq metres.
In order to establish the air flow rate that would give
the same pressure drop through a 1 sq metre face
area louvre therefore the volumes given would be
divided by a factor of 4.
Two different weather louvre designs are available.
The Type NVT/1 is our standard single bank design
and the Type NVT/2 is a single bank design with
additional rear eliminator channels. Whilst both of the
designs meet class A specification the Type NVT/2
offers the extra degree of weather ingress protection
that may be required for certain projects.
Natural flow of
air to and from
building
depending on
design
requirements
and temperature
differentials
Exhaust on
leeward side
Wind
pressure
Graph A Graph B
26
Penthouse LouvrePerformance DataThe following tabulated table provides comprehensive
sizing data for all of our standard size penthouse
turret louvre range.
Figures in the table are based upon air volume
and duct velocity variables and these can easily
be changed within a selection program to give
new data on alternative sizes where required.
Eliminator
N
N
N
N
N
N
Y
Y
Y
Y
Y
Y
Unit
VNT/1
VNT/2
Nom Size
(internal
duct size)
400
600
800
1000
1200
1400
400
600
800
1000
1200
1400
Nominal Height
(Blades x 75)
225
300
375
525
600
675
225
300
375
525
675
750
Theoretical
Blade
Requirement
3
4
5
7
8
9
3
4
5
7
8
9
Standard
Blade Qty’s
3
4
5
7
8
9
3
4
5
7
8
10
Modified
Blade
Qty
3
4
5
7
8
9
3
4
5
7
9
10
Over
Blade Size
765
965
1165
1365
1565
1765
765
965
1165
1365
1565
1765
Structural
Opening
(on plan)
532
732
932
1132
1332
1532
532
732
932
1132
1332
1532
Free
Area of
Duct
0.16
0.36
0.64
1.00
1.44
1.96
0.16
0.36
0.64
1.00
1.44
1.96
Geometric
Free Area
through
Louvre
0.19
0.39
0.64
1.14
1.56
2.05
0.19
0.39
0.64
1.14
1.76
2.28
Volume at
1m/s
through
Duct (l/s)
160
360
640
1000
1440
1960
160
360
640
1000
1440
1960
Active
Face Area
of Louvre
(m2)
0.57
1.03
1.60
2.61
3.48
4.47
0.57
1.03
1.60
2.61
3.85
4.91
l/s/m2 of
Louvre
(Face
Velocity)
279
350
400
384
414
438
279
350
400
384
374
400
LEGEND:
Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Standard order code
Eliminator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Two Alternatives, recommend Type 1 for wind catchers and Type 2 for stacks for water ingress reasons
Nominal Size (internal duct size) . . . . . . . . . . . . . .This will be the list size, the internal dimensions of the stack
Nominal Height (blades x 75+320) . . . . . . . . . . . . .The total height of the unit including lid and plinth from the top surface of a flat roof
Theoretical Blade Requirement . . . . . . . . . . . . . . .This is the quantity of blades required to get the louvre blade free area to equal or to the desired ratio over stack free area
Standard Blade Qty . . . . . . . . . . . . . . . . . . . . . . . .This is the quantity of blades proposed for the standard product, sized to give a coefficient of discharge above 0.5
Proposed Blade Qty . . . . . . . . . . . . . . . . . . . . . . . .This is the quantity of blades used to calculate the Heights/Pressures/areas/coefficients of discharge.
Over Blade Size . . . . . . . . . . . . . . . . . . . . . . . . . . .The overall size of the units
Structural Opening (on plan) . . . . . . . . . . . . . . . . .The size of the opening required in the roof skin
Free Area of Duct . . . . . . . . . . . . . . . . . . . . . . . . . .Stack internal width x internal length (footprint)
Geometric Free Area through Louvre . . . . . . . . . . .The total free area path through the four faces of the unit
Volume at 1m/s through Duct (l/s) . . . . . . . . . . . . .Volume flow rate through the louvre at 1m/s stack velocity (likely velocities may be 0.25 to 0.5
Active Face Area of Louvre (m_) . . . . . . . . . . . . . .The active area of the unit, 4 x blade pack height x width between internal blade end supports (if
l/s/m2 of Louvre . . . . . . . . . . . . . . . . . . . . . . . . . . .Volume passing through the louvre (at 1m/s) / Active face area -Relates to the pressure drop tests
Pressure Drop@ 1m/s . . . . . . . . . . . . . . . . . . . . . .Pressure drop on the Terminal unit with 1m/s coming out of the stack
Pressure Drop@ 'above' m/s . . . . . . . . . . . . . . . . .Pressure drop on the unit with the duct velocity setting in the square above the table (user settable)
Pressure Drop@ 'above' l/s . . . . . . . . . . . . . . . . . .Pressure drop on the unit with the air volume setting in the square above the table (user settable)
Terminal Coefficient of Discharge (or entry) . . . . . .Coefficient of discharge of a terminal unit -(open duct ~1, with terminal sized for 0.5 min, or 100% free area ratio min)
Louvre Coefficient of Discharge . . . . . . . . . . . . . . .Coefficient of discharge of a single louvre unit weight
Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Unit weight not including duct and skirt
Nominal Duct Length . . . . . . . . . . . . . . . . . . . . . . .Nominal length of duct for roof angles and thickness set in boxes above the table
To use as a selection calculator please contact Gilberts Technical Department
27
Unit
VNT/1
VNT/2
Pressure
Drop@
1m/s
0.58
0.92
1.20
1.10
1.28
1.44
0.86
1.35
1.76
1.62
1.54
1.76
Pressure
Drop@
above m/s
9.33
14.72
19.16
17.66
20.54
23.02
13.69
21.59
28.10
25.90
24.60
28.10
Pressure
Drop@
above m/s
364.50
113.60
46.77
17.66
9.91
5.99
534.60
166.62
68.60
25.90
11.87
7.31
Terminal
Coefficient
of
Discharge
0.712
0.628
0.578
0.593
0.564
0.542
0.642
0.555
0.505
0.520
0.530
0.505
Louvre
Coefficient
of
Discharge
0.283
0.283
0.283
0.283
0.283
0.283
0.234
0.234
0.234
0.234
0.234
0.234
Weight
22
35
51
79
104
134
26
42
62
95
125
172
Nominal
Duct
Length
1400
1600
1800
2000
2200
2400
1400
1600
1800
2000
2200
2400
28
Acoustic SilencerMistrale model Type C provides the facility to
include an acoustic silencer to reduce noise
migration from external sources. Although the
combination of louvres, dampers and coils on
other models does provide some degree of
noise reduction for more urban areas an extra
degree of noise reduction may be desirable.
The Mistrale model Type C is particularly suited
since it is designed to be installed either above
the ceiling or below the floor where the extra
depth required for a silencer is less critical.
Two silencer models are available with the
Type 1S just 220mm deep and the Type 2S
presenting at 420mm deep.
Noise reduction performance guidance for
various configurations including the silencer
model Type 1S is provided on page 29.
Effective damper width +200mm
Effective damper width +300mm22
0 de
pth
220 or 420 depth
Effe
ctiv
e da
mpe
r hei
ght
Effe
ctiv
e da
mpe
r hei
ght
29
Acoustic InformationExtensive acoustic testing has been carried out
in order to establish the noise reduction values
which can be reasonably expected from each
component of our Natural Ventilation assembly.
Whilst heating/cooling coils give limited
reductions both the weather louvres and
dampers do contribute to the overall noise
reduction index.
A slim 200mm deep acoustic silencer was
also tested with the other key components to
provide a higher performance acoustic option
if required.
The figures provided below illustrate the 1/3
octave db reductions in sound pressure levels
when measured in accordance with BS EN ISO
140-3:1995 (sound reduction index) and BS EN
20140-10 1992, ISO 140-10:1991 (elemental
normalised level difference).
Unit Area
1 m2
0.5 m2
0.25 m2
0.125 m2
63
3
6
9
12
125
4
7
10
13
250
6
9
12
15
500
9
12
15
18
1.0k
14
17
20
23
2.0k
20
23
26
29
4.0k
24
27
30
33
Rw
14
17
20
23
Dn,e,w
22
25
28
31
MEAN FREQUENCY (OCTAVE BANDS) Hz
SOUND REDUCTION INDEX FIGURES (dB) for WEATHER LOUVRE + OPENDAMPER (acoustically lined blades) +200 WIDE TUBULAR SILENCER
Unit Area
1 m2
0.5 m2
0.25 m2
0.125 m2
63
3
6
9
12
125
4
8
10
13
250
3
7
9
12
500
4
8
10
14
1.0k
7
11
14
17
2.0k
10
14
17
20
4.0k
14
18
19
26
Rw
8
12
15
20
Dn,e,w
16
19
22
25
MEAN FREQUENCY (OCTAVE BANDS) Hz
Unit Area
1 m2
0.5 m2
0.25 m2
0.125 m2
63
3
6
9
12
125
4
7
10
13
250
3
6
9
12
500
4
7
10
13
1.0k
5
8
11
14
2.0k
6
9
12
15
4.0k
10
13
16
19
Rw
5
8
12
17
Dn,e,w
14
17
20
23
MEAN FREQUENCY (OCTAVE BANDS) Hz
Unit Area
1 m2
63
12
125
12
250
12
500
22
1.0k
27
2.0k
32
4.0k
35
Rw
26
Dn,e,w
34
MEAN FREQUENCY (OCTAVE BANDS) Hz
AS ABOVE WITH DAMPER HALF OPEN
AS ABOVE WITH DAMPER CLOSED
NoteIf RW figures have been
given on a reduced
opening area they have
been calculated back
to a 1m2 opening.
SOUND REDUCTION INDEX FIGURES (dB) forWEATHER LOUVRE + OPEN DAMPER (acoustically lined blades)
30
Mistrale Natural Ventilation Control
The Mistrale fresh air Natural Ventilation unit marks a new
era for room environmental controls. It greatly simplifies the
building infrastructure normally required with fan coil units
by removing the need for large air handling units and ducting
systems within the building. Fresh air is supplied directly to
each room space as required avoiding cross contamination
and providing a level of freshness ‘like opening a window’.
Mistrale has no fan. It is therefore quiet and energy efficient.
Mistrale units are available with the following control
options�
• Manual fresh air control with no heating or cooling
requirement.
• Fresh air control with free cooling.
• Fresh air control with free cooling and hot water heating
coil.
• Fresh air control with free cooling, chilled water cooling
and hot water heating.
Air quality can be maintained by fitting a room CO2 sensor
to any of the above options. This provides automatic fresh
air control. A humidity sensor can also be fitted to manage
condensation in bathrooms and wet areas.
The controls are mounted inside the ventilation unit and
manage the complex relationship between dampers,
actuators and temperature measurements.
An attractive LED wall control provides a simple intuitive
control for settings such as space temperature and fresh air
level. A 3 button 2 line LCD control panel is used to set up
the control parameters, set-points and options for a room or
local area. The LCD also displays system parameters and
fault conditions such as sensor fail or low temperature
conditions.
The room space temperature sensor and CO2 sensor are
mounted on the wall in a small brushed stainless steel
enclosure which matches the wall control plate and provides
durability.
The system extracts air at a high level using body heat and
temperature gradients within the space to drive the airflow.
Extract dampers are controlled directly from the unit.
Controllers in different room spaces can be linked by a
twisted pair network to control a common extract damper.
High limit sensor(ref.9)
Heat exchangers heating or cooling
TC02 Controller (ref.1)
water valve actuators (ref.7&8)
Low limit sensor (ref.10)
Fuse spur (ref.12)
Mistral LCD area control plate option (ref.2)
Mistral LED control plate (ref.3)
Extract damper (ref.6)
CO2 and temperature sensor (ref.4)
Mistral Computer control option
Damper actuator (ref.5)
Outside air sensor (ref.11)
Ref
Ref1
Ref2
Ref3
Ref4
Ref5
Ref6
Ref7
Ref8
Ref9
Ref10
Ref11
Ref12
Component description
TC02 controller din rail mount with transformer
TCB LCD panel display for area control
TCB LED panel display for room control
CO2 and temperature sensor unit
Damper Actuator
Damper Actuator
Water valve actuator
Water valve actuator
High limit sensor
Low limit sensor
Fresh air sensor
Fused spur 230 Vac
Positioned by
Gilberts
Client
Client
Client
Gilberts
Gilberts
Client
Client
Client
Client
Client
Client
Wiring Connection
Gilberts
Client to controller (Belden 8723)
Client to controller (Belden 8723)
Client to controller (Belden 8723)
Gilberts within unit
Gilberts within unit
Client to controller flying lead
Client to controller flying lead
Gilberts flying lead
Gilberts flying lead
Gilberts flying lead
Client power flex
31
Control Strategy
The system maintains space air at the requested temperature
set-point with closed loop PID control by monitoring a wall
mounted air temperature sensor.
To save energy the system utilises free heating or cooling
as required.
There are 4 modes of operation, 2 heating and 2 cooling...
• Free heating (if supply fresh air is warmer than inside
air temperature)
• Standard heating (if supply fresh air is cooler than inside
air temperature)
• Free cooling (if fresh air is cooler than inside air temperature)
• Standard cooling (if fresh air is warmer than inside
air temperature)
If the unit enters free heating or cooling mode the system will
stay in this mode until it has remained at 100% capacity for
5 minutes (default) without achieving set-point temperature.
Only after this period will it switch to using heating or cooling
energy.
The system offers four fresh air level settings. With manual fresh
air control the dampers are opened by fixed amounts
for each setting with automatic control the dampers maximum
opening is limited to the setting. These amounts are configurable
from the LCD display. For example setting 1 opens the dampers
to 25%, setting 2 to 50%, setting 3 to 75% and setting 4 to
100%. In automatic mode the damper position
is regulated according to the difference between actual
and requested temperature.
During free heating or cooling the fresh air level settings have
no effect as the dampers are modulated to control space
temperature.
Space set-point and fresh air level settings are controlled from
a wall mounted plate this has two buttons and 10 LEDs, 5 for
set-point and 5 for fresh air level. Set-point is selectable by
pressing the top button which cycles through the five settings
(LED colour in brackets), from left to right these are 17°C (blue),
19°C (blue), 21°C (green), 23°C (red), 25°C (red). Fresh air level
is indicated by 5 green LEDs as off, 1, 2, 3, and 4. These
settings are also available for the LCD unit.
The fresh air damper will close if the water coils are in danger
of freezing (outside air temperature below 2°C default). The
maximum opening position of the fresh air damper will be
limited to a fixed value (default 10%) under extreme low
outside temperature conditions (default below 10°C).
Under these conditions the fresh air dampers will not be
influenced by the CO2 sensor.
The CO2 level of the room air is monitored and at 950ppm
(CO2 hi default) the fresh air and extract dampers are opened by
approximately 3% more. Once triggered, for every 1 minute
period (default) that the CO2 level remains above 950ppm
(CO2 hi default) the dampers are opened by a further 3% until
fully open. For every 1 minute period (default) the CO2 level falls
below 900ppm (CO2 lo default) the dampers are closed by 3%
until back to its original position. The damper position is left
unchanged if the level remains between the CO2 hi
and CO2 lo limits.
During free cooling the fresh air temperature entering the room
is monitored and if it is 3°C less than the set-point temperature
is tempered with the heating coil. The cool air entering the room
will never be more than 3°C below the set-point. This avoids
a very cold layer of air building up at floor level.
A temperature sensor also monitors the low pressure hot water
system and only allows the damper to open if hot water is
available.
The surface temperature of the outlet grille can be optionally
monitored to limit the surface temperature to approximately
40°C.
A seven day time clock is available with two on/off settings per
day. At switch on time the default room set-point and fresh air
settings are automatically selected. During the off period the
unit can be manually turned on from the LED wall plate, after
two hours the unit will automatically switch off.
A night cooling feature is available during the summer months,
which allows cool air to enter the room space during the night
cooling the building infrastructure. This provides a level of free
cooling the following day.
Network Connection Network connection points can be Ethernet or RS485 type. Ethernet allows for connections to be made to an existing infrastructure. This may be a convenient option in larger buildings with well defined communication RS485 is ideal for the more industrial or smaller building. Network with Modbus protocol can be supplied. This allows for connection to main BMS.
Dumb slave units save the controller cost. The dumb slave unit must be wired to the nearest Master Mistrale Controller. All actuators and dampers will be driven directly by the master.
Intelligent slave units save the site wiring cost. The intelligent slave unit must be connected to the chosen Master nearest Master Mistrale Controller. All actuators and dampers will be driven directly by the Slave under control of the master.
Mistrale controller in unit
Wiring to controller
Wiring to controller
Local LON connection Belden 8723
Local LON connection Belden 8723
Group option shows Mistrale and 2 dumb slaves
Group option shows Mistrale and 1 dumb slave
Typical local Mistrale unit network 1 to 32 units
Typical local Mistrale unit network 1 to 32 units
Mistrale LCD area control plate option
Mistrale LCD area control plate option
Internet connection
Mistrale computer control option
RS485 Communications Belden 8723
RS485 Communications Belden 8723
Group option shows Mistrale and 1 intelligent slave
Group option shows Mistrale and 2 intelligent slaves
32
MISTRALE LCD display
The LCD unit may be used to provide a programmable interface to the Radiator
system for overall strategy and comfort control.
A switch on the LCD unit displays its module address for about 4 seconds.
Up to 8 LCD units can be connected to the LON cable, which can be up to
100m long. Each LCD unit must be given a different module address (0 to n).
To set the LCD module address hold down all three buttons for >10 seconds.
The unit will then display “module X”, press the right button to increase the module
address and the left button to decrease it.
Pressing the centre button selects the next menu item, which is the LCD backlight on
time, this can be between 1 and 25 seconds or OFF for always off and ON for always
on. Once set up just wait 10 seconds (without pressing a button) for the display to
return to normal and the new settings to be saved.
MODBUS
The TC02 unit supports the MODBUS RTU open network protocol. This allows
connection to any standard BMS, a PC based area control system or HID panel.
The hardware interface is half duplex RS485 (single twisted pair) and we normally
use a unit load driver chip with +/-60 volt line protection (LT1785CN8).
There are four screw terminal connections on the board these are RS485 B, RS485 A,
Shield In, and Shield Out. Either or both Shield In and Shield Out can be connected
to local ground via a jumper link. Normally only the Shield Out is linked to local ground.
The open protocol we use is MODBUS RTU at 19200 baud, no parity, 8 data bits,
and 1 stop bit. Each unit has a network address ID from 1 to 247 (8bit) settable
from the LCD interface.
The following MODBUS function codes are implemented�
Read Holding Registers (3)
Write Single Register (6)
Write Multiple registers (16)
LON LED HVAC plate Specification
The LON LED HVAC plate is design as a direct replacement for the standard
plastic wall units found on many HVAC systems.
The unit consist of user display board of approximately 95 x 60 mm fitted
with a stainless steel front plate. This board has ten LEDs and two push buttons for
controlling damper positions and set point. It is connected to the TC range of control
units via a twin twisted pair cable.
• Can be surface or flush mounted in a standard UK back-box or patress.
• Simple multi-drop digital twin twisted pair connection to controller.
• Powered via the twisted pair cable.
• Five temperature settings indicated by multi-colour LED’s
• Four Fresh Air damper positions and ‘closed’ indicated by five LED’s.
• Flashing LED’s indicate status information such as Damper or sensor fail.
• Engineering mode for full system status.
• Front plate Standard Supply is Brushed Stainless Steel (plates can be
customised to client requirements, e.g. brass or anodised aluminium.)
Control Display Options
System Performance
0.1 1.0 10 1
2
3
9 8 7 6 5 4 3 2
4
5 6 7 8
1 9
2
3
4
7 6 5 4 3 2 9 8 1
2
3
4
5 6 7 8
1 9
2
3
4
6 5
7 8 9 1
3
2
4
5
1
6 7
9 8
1 4 3 2 1 9 8 7 6 5
6 5
7 8 9 1
3
2
4
5
7 2 6 5 4 3 1 9 8
6 7
9 8
1
Face Velocity m/s
Pre
ssur
e (P
a)
Natural Ventilation Unit
Pressure Drop
33
Unit Size
1300 x 600
1300 x 400
1300 x 200
800 x 600
800 x 400
800 x 200
300 x 600
300 x 400
300 x 200
Effective
Area m2
0.78
0.52
0.26
0.48
0.32
0.16
0.18
0.12
0.06
Volume @
0.3 m/s
effective
face
velocity
0.234
0.158
0.078
0.144
0.096
0.048
0.053
0.036
0.018
Pressure
drop (Pa)
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.6
Ce
1.18
1.18
1.18
1.18
1.18
1.18
1.18
1.18
1.18
Example
Example
For the sizing of all unit types when incorporated into building
designs please refer to Gilberts selection software program
Alternative effective face velocities can be selected from the graph with
revised pressure details
Although pressure/volume graphs are provided
for individual components the information here
provides pressure loss details for a complete
natural ventilation assembly.
Data based on Model Type A for all standard
sizes.
34
Ordering SpecificationNatural Ventilation Unit
Product Reference (VN)
Damper + Coil + Silencer (depending on model selected)
External Louvre
Internal Grille
VN/100
VN/WH /Z /32 /BG /WC RAL 9060 75 1560 x 716
/A 1300 x 606 1560 x 716 /2A /IN /AF /RH /H /1S
Model A to F
Effective Damper Width x Height (mm)
Minimum structural opening size to suit Could be larger with louvre size specified
Drive System Manual or motorised Ref. 1 to 9
Structural Opening (Width x height mm)
Structural Opening (Width x height mm)
If Border Size Z Specified Above, Glass Thickness (mm)
Drive Handing RH or LH (As viewed from inside)
Coil Type /H or /HC (Models A, B or C only)
Silencer Type/1S or /2S (Model C only)
Product Reference VN/WH or WG
Border Style C, F or Z
Guard Options IS or BG
External Finish RAL Colours etc
Internal Finish RAL 9010 standard
Internal Grille Types (with low surface temp option Ref. LST)
Weather Cill (WC) Border Style “C” only
Louvre Blade Pitch 38, 75 or 100
Blade Insulation Required (IN)
Adjustable Feet (AF)
VN/RP-1 1560 x 716 RAL 9010
VN/RP-1 Curved Routed Panel (Model A) VN/RP-1/LST Curved Routed Panel (Model A) VN/RP-2 Flat Routed Panel (Models B, D & F) VN/RP-3 Flat Routed Panel (Models A, C, D & F) VN/RP-3/LST Flat Routed Panel (Models A, C, D & F) VN/KO Grille (Models B, D & F) VN/K15 Grille (Models B, D & F) VN/K40 Grille (Models B, D & F) VN/SKO Grille (Models B, D & F) VN/GE Grille (Models B, D & F)
35
Product ReferenceVNT-1 standardVNT-2 with eliminator
Penthouse Turret
VNT-1 /2 600 x 600 1000 B1 3
Type (1 to 5)
Nominal Size (width x height)
Insulated duct length400 to 2000mm in 200mm increments
Roof & curb details
Drive actuator options (3 to 9)(Types 3, 4 & 5)
NOTE: For detail of border types B2, B5 & B6 contact Gilberts Technical Department
Plinth (type 1 only) Illustrated B1Flat ‘C’ Bottom frame (type1 only) Not illustrated B2Flat slab type roof and curb Types 2, 3, 4, B4 illustratedPitch cladded roof (angle of slope) Max 45° Types 2, 3, 4, B5(12) not illustratedPitch tiled roof (angle of slope) Max 45° Types 2, 3, 4, B6(12) not illustrated
Ordering SpecificationPenthouse Terminals
Gilberts (Blackpool) Limited
Clifton Road, Blackpool FY4 4QT Telephone 01253 766911 Fax 01253 767941
Email: [email protected] Web: www.gilbertsblackpool.com
Gilberts (Blackpool) Ltd reserve the right to alter the specification without notice. For our latest product data please visit www.gilbertsblackpool.com
The information contained in this leaflet is correct at time of going to press © 2009.