EPP Air Handling Unit with
swept internal air flow paths
Steel powder coated frame
External insulated volume
control damper
Acoustic Air treatment zone
24V Actuators to
dampers
Internal louvre grille supplied
as a standard in white.
Other colours available upon
request
Linear grille for recirculation
and natural ventilation air
paths
Recirculation and natural
ventilation air volume
control damper
Halifax House,
Cressex Business Park
High Wycombe
Buckinghamshire HP12 3SE
T: +44 (0) 1494 897700
F: +44 (0) 1494 532465
E: info@monodraught.com
W: www.monodraught.com
Façade Plus series (F+)
Hybrid Thermal Mixing (HTM) system - Façade Plus series (F+)
The Hybrid Thermal Mixing (HTM) system from Monodraught is designed to provide natural ventilation, hybrid
ventilation incorporating mixed tempered air for winter periods with the ability to provide secure night time cooling
and boosted levels of ventilation during summer. The system is designed to work in conjunction with natural
ventilation provided by manual or automatic windows and can be used in single sided or cross flow ventilation
strategies. The units can be mounted horizontally above windows or mounted vertically to the sides of rooms and
can also be ducted to provide ventilation to deep plan rooms.
The system comprises of an intelligent and fully automatic control system coupled with a low energy ventilation
system which switches between operational modes dependant on season, external/internal temperature
conditions and indoor air quality (IAQ).
Designed to meet Priority School Building Programme requirements, the Monodraught HTM F+ series uses
exceptionally low specific fan powers and features an intelligent control system which is supplied as standard with
full data logging facility, temperature control and CO2 control. With the optional BACnet module, each unit has the
ability to output key performance data to a central BMS to show compliance within PSBP guidelines.
TECHNICAL DETAILS
• Material:
»» EPP (Expanded Polypropylene) 100% recyclable.
»» ABS, aluminium and rubber sealed volume control dampers.
»» Composite high density glass wool cladding.
• Performance:
»» Daytime hybrid ventilation rate of approximately 200 l/s (SFP 0.15).
»» Night time hybrid ventilation rate of approximately 300 l/s (SFP 0.30).
»» U-value through external air shut off damper = 1.2 Wm²K.
»» Air tightness = 2 m3/h/m² @50Pa.
• Options:
»» BACnet BMS interconnection module.
»» Alternative grille colours available on request.
• System Requirements:
»» Connection to clean outside air source (inlet positioned away from sources of pollution).
»» 240V 3A fused switched spur mounted within 1m of unit.
2
F+
System Width
Natural Ventilation
Effective Free Area
Weight of System
Typical Louvre Size
required (50%)
1000 mm
0.36 m2
32 kg
1300 mm x 500 mm
1500 mm
0.5 m
40 kg
1800 mm x 500 mm
2
Façade Plus series (F+)
• Dimensions:
»» 1000 mm deep x 500 mm high, width varies with model.
SPECIFICATION
Hybrid thermal mixing ventilation system to suit a façade application.
Each system is supplied complete with a fully automatic control system managing a low energy fan, insulated
external volume control damper with rubber sealed low leakage aerofoil blades and re-circulation volume
control damper. System constructed from EPP airflow paths and composite panels providing high levels of
acoustic operation and composite panels to meet BB93 requirements.
Systems are available in two widths of 1000 mm or 1500 mm wide with an overall height 500 mm and a depth
of 1000 mm. Installed using drop rod (provided by others) or Gripple® supports with white panel finish or
boxing in by others following installation.
White louvred supply grille and white linear recirculation grille are provided as standard.
Fully automatic intelligent control system with traffic light indicator for manual window operation, temperature
and carbon dioxide sensing and user overrides. Seasonal time and date clock built in with full data logging
functionality. Optional BACnet module is available to allow BMS data interconnection.
An external weather louvre (provided by others) is required for connection to HTM F+. Louvre panel to be
supplied fitted with bird guard mesh and a spigot/ transition.
HTM F+ system to be capable of providing an assisted ventilation rate of 200 l/s and night time purge mode of
300 l/s to provide secure night time cooling. Each system to provide a natural ventilation air path to assist
natural ventilation through openable windows and reduce fan operation.
CONTROLS AND USER INTERFACE
Wall mounted user controls with:
•
•
•
•
3
Room Temperature and CO2 sensor.
On/Off control.
High, Medium(auto) and Low fan speed settings.
LED wall panel to indicate when to open windows.
F+
Façade Plus series (F+)
TYPICAL INSTALLATION/OPERATION DETAIL
• Cross Flow:
Openable windows
Summer Day
Summer Night
Winter Day
Monodraught HTM F+ system mounted at the rear of a room to assist with cross flow ventilation using
openable windows on the facade. System automatically provides secure night time cooling through natural
ventilation opening or fan assisted if required. Winter ventilation automatically modulates dampers to mix
re-circulated air with external air to ensure optimum ventilation temperatures.
• Single Sided Flow:
Openable windows
Summer Day
Summer Night
Winter Day
Monodraught HTM F+ system mounted on the façade (can be ducted to provide ventilation to the rear of deep
plan rooms) to assist with single sided ventilation using openable windows. System automatically provides
secure night time cooling through natural ventilation opening or fan assisted if required. Winter ventilation
automatically modulates dampers to mix re-circulated air with external air to ensure optimum ventilation
temperatures.
• Single Sided Flow:
Classroom 1
Classroom 2
Full height glazing & openable windows
Section - Summer Night
Section - Winter Day
Plan View - Summer Day
Monodraught HTM F+ units can be mounted vertically on the façade and can be ducted to provide ventilation
to the rear of deep plan rooms to assist with single sided ventilation from manually openable windows. The
duct can be a builders work plenum and is shown here with three linear grilles. This installation method allows
full height glazing to be used at the elevation to maximise daylight levels within the room.
4
F+
• Optional Connections
Façade Plus series (F+)
WIRING DETAILS
• Standard Connections
OPTIONS
• Widths – 1000 mm, or 1500 mm (10 or 15).
• Horizontal or Vertical Mounting (H or V).
• White panel finish for exposed installation or Silver panel finish for boxing in by others (W or S).
• Order code example – HTM F+ (15, H, W).
Controls interconnection options include:
• Master / slave mode to synchronise multiple units in a single zone.
• Inhibit input to enable / disable HTM F+ series system from BMS or Fire Alarm circuit.
TYPICAL SPECIFICATION
...No. Monodraught Hybrid Thermal Mixing ventilation systems to suit a façade application (HTM F+ code).
Overall dimensions are 1000 mm/1500 mm wide x 1000 mm deep x 500 mm high.
Each system is supplied complete with a low energy fan to provide 200 l/s (SFP 0.15) for mixed ventilation
air, with the capability for night time purge mode of 300 l/s (SFP 0.30) to provide secure night time cooling,
an insulated external volume control damper with rubber sealed low leakage aerofoil blades and a
re‑circulation volume control damper.
The system comes complete with a fully automatic intelligent control system including a wall mounted
controller with integral temperature & carbon dioxide sensor, user overrides, and a traffic light indicator to
advise room occupants regarding window operation. A built in seasonal time and date clock with full data
logging functionality is also included.
5
F+
Façade Plus series (F+)
The system is constructed from EPP airflow paths with composite cladding, providing high levels of acoustic
attenuation and is supplied with Gripple® fixings for installation. The HTM is suitable for boxing in following
installation.
Please note, the external weather louvre and transition to HTM are to be supplied, by others. Monodraught
are able to provide a separate quotation for these items if required.
CONTROL STRATEGY
The HTM F+ incorporates a fully automatic control system based on a seasonal control strategy. The seasonal
strategy is determined by time and date but is weather compensated to pick up unseasonal conditions. The
system looks to provide natural ventilation as the default method of ventilation indicating when manual
windows should be utilised to maximise IAQ and maintain comfort levels.
The control system incorporates a number of temperature sensors integral to the unit to monitor external
temperature, mixed air temperature and supply air temperature. In addition, a wall mounted controller
fitted with an internal temperature, CO2 sensor and user override and a manual window traffic light indicator
are included as standard. Data is stored per minute on an integral data card for data analysis and compliance
requirements as required.
During daytime periods in the Spring, Summer and Autumn seasons, if the internal room temperature
exceeds 26°C or the CO2 level goes above 1500 ppm, the system will provide a boosted level of ventilation
until which time optimum conditions are met. If the external temperature is below 15°C the system will
operate under a hybrid ventilation strategy as per winter mode.
During Summer periods between midnight and 7 am and the internal temperature is above 18°C, the system
will provide night time cooling providing a peak ventilation rate of 300 l/s until such time that the internal
temperature goes below 18°C.
During Winter periods the system will operate under a hybrid ventilation strategy utilising the fan to mix and
re-circulate warm room air to minimise cold draughts.
All settings are customisable during commissioning phase.
WINTER TIME THERMAL MIXING
Depending on the external air temperature, the system will introduce ventilation air mixed with recirculated room air with the ratio of mixed to fresh air to minimise cold draughts and maintain IAQ / comfort
conditions. Generally the system will try to supply a mixed air temperature above 15°C.
• Thermal Mixing Conditions:
»» Internal room temperature = 23°C
»» Ventilation rate set at 200 l/s
»» External Temperature range varies
»» Mixing of recirculation and external air supplies vary to maintain minimum supply air temperature of 15°C. System automatically modulates over 100% and these mixing levels are for representation only.
6
F+
Façade Plus series (F+)
Internal Room Temperature 23oC
Ventilation Rate 200 l/s
External Temperature range varies
Mixing of recirculation and external
air supplies vary to maintain minimum
supply air temperature of 15 oC.
System automatically modulates over
100% and these mixing levels are for
representation only
Resulting mixed air temperature passed into room
(temperature reading 1 m from edge of diffuser)
Thermal Mixing Conditions
20
15
Min supply
temperature
10
5
0
Text 15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
Mixing Rate 2:5 - 60 l/s Fresh air 140 l/s Recirculated air
20.8 20.6 20.5 20.4 20.3 20.2 20.1 20.0 19.9 19.8
19.7 19.4 19.1 18.8 18.4 18.1 17.9 17.7 17.5 17.2
17.0
Mixing Rate 1:2 - 70 l/s Fresh air 130 l/s Recirculated air
20.4 20.2 20.0 19.9 19.7 19.6 19.4 19.3 19.1 19.0
18.8 18.5 18.1 17.7 17.4 17.0 16.7 16.5 16.2 15.9
15.6
Mixing Rate 2:3 - 80 l/s Fresh air 120 l/s Recirculated air
19.9 19.6 19.4 19.1 18.9 18.7 18.5 18.3 18.0 17.8
17.6 17.1 16.7 16.3 15.9 15.4 15.1 14.8 14.4 14.1
13.7
Mixing Rate 3:4 - 85 l/s Fresh air 115 l/s Recirculated air
19.7 19.3 19.1 18.8 18.6 18.3 18.1 17.8 17.6 17.3
17.1 16.6 16.2 15.7 15.2 14.8 14.4 14.0 13.7 13.3
12.9
Mixing Rate 4:5 - 90 l/s Fresh air 110 l/s Recirculated air
19.5 19.2 18.9 18.7 18.4 18.1 17.9 17.6 17.3 17.1
16.8 16.3 15.8 15.4 14.9 14.4 14.0 13.6 13.2 12.9
12.5
Mixing Rate 1:1 - 100 l/s Fresh air 110 l/s Recirculated air
19.1 18.7 18.4 18.0 17.7 17.4 17.1 16.8 16.4 16.1
15.8 15.3 14.7 14.2 13.7 13.1 12.7 12.2 11.8 11.4
10.9
Mixing Rate 3:2 - 120 l/s Fresh air 80 l/s Recirculated air
18.3 17.8
Mixing Rate 2:1 - 130 l/s Fresh air 67 l/s Recirculated air
17.7 17.2 16.7 16.2 15.7 15.2 14.8 14.3 13.8 13.3
12.8 12.1 11.4 10.7 10.0
Mixing Rate 3:1 - 150 l/s Fresh air 50 l/s Recirculated air
17.1 16.4 15.9 15.3 14.7 14.2 13.6 13.0 12.5 11.9
11.3 10.6
8.2
7.4
16.9 16.5 16.1 15.7 15.3 14.8 14.4
14.0 13.4 12.7 12.1 11.5 10.8 10.3
9.8
9.2
8.7
8.1
9.3
8.7
8.1
7.5
6.9
6.3
7.5
6.8
6.1
5.4
4.7
4.1
6.8
9.0
TESTING
During December 2013 an HTM F+ system was installed within a climatic test chamber and a special heat
sensitive membrane was fitted running through the centre of the system. An insulated chamber fitted below
the HTM F+ system was heated to 23°C to represent an internal room condition. Thermal imaging video
cameras were used to record the temperature profile of the mixing of air in real time. The thermal imaging
cameras were set to record three zones with averaged temperature readings within each zone :- external air
temperature, internal room air temperature and mixed supply air temperature. The system was then set to
provide 200 l/s of mixed ventilation air to represent maximum daytime ventilation rates.
Zone 1 is recording the external air
temperature with an average temperature
within the measured zone of 11.7°C
Zone 2 is recording an internal room
temperature with an average temperature
within the measured zone of 22.7°C
Zone 3 is recording the mixed air supply
temperature with an average temperature
within the measured zone of 16.4°C
7
F+
DELIVERING
SUSTAINABLE
SOLUTIONS
1974 - 2014