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Demand controlled mechanicalextract ventilation (DCMEV)
Guidance for residential installations
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345678
1011
IntroductionExtract and inlet terminalsPositioning of inlets /
grille terminals for air transferFan selectionFan
installationDucting installationSystem verification and
instructionInstallation schematic
Contents
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3This guide is intended to briefly outline the principles
underly-ing the installation of Aereco systems. All components of
the system should be fitted in accordance with manufacturers
specifications and the system design schematic.
Aereco offers ventilation adapted to the needs and demands of
the occupants, while ensuring that Indoor Air Quality (IAQ) is not
compromised. Demand Controlled Ventilation adapts airflow directly
at the source of the pollutant, ensuring that the dwelling is
neither over-ventilated nor under-ventilated. Control is achieved
through use of new generation tech-nologies detecting key
pollutants known to affect IAQ, such as humidity, CO
2, VOC (Volatile Organic Compounds); which
can lead to a build up of condensation, the formation of mould,
and some respiratory conditions.
Good ductwork installation is the key to an effective
venti-lation system. Sub-standard installation leads to increased
energy consumption and poor indoor air quality.
Systems should be installed in accordance with manu-facturers
instructions, as shown on M&E drawings. These drawings are
typically for guidance purposes, and rely on the competence of the
contractor undertaking the works. This guide will provide a
practical approach to such installations, and will make reference
to obligatory standards / regulations.
Ductwork for Aereco DCMEV (Demand Controlled Me-chanical Extract
Ventilation) should be installed to the following standards;HVCA
Standard DW/154 for Plastic DuctworkHVCA Standard DW/144 for Sheet
Metal Ductwork
The component sizes for individual dwelling systems are 204x60mm
and 125mm, using plastic duct. For collective dwelling / communal
installations, sizes range from 100mm-630mm using metal spiral
duct, connecting to the VEC range fan units (not covered in this
document).
Introduction
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4Extract and inlet terminals
Product selection
Aereco has a range extract terminals (see BXC Brochure
FLY447GB), offering a flexibility of control using innovative
integral sensory equipment. Aereco appreciates that humidity is a
main indicator of IAQ within dwellings, and invented the Hygro
control sensor for this purpose.
The Hygro exploits the expansion and contraction of nylon when
exposed to moisture. Harnessing this property has enabled
energy-free control of the aperture size of grille terminals, which
results in a change to the rate of ventilation when combined with a
constant pressure / variable volume fan unit.
Further controlled adjustment to ventilation, by alternative
means, can be offered with or without the Hygro sensor. For
example, smart adjustments can be made with the option of a
pyroelectric (PIR) sensor detecting movement (which only adjusts
airflow when presence is continually detected). The sensor can also
be adjusted to prevent wasteful over-ventilation, such as being
activated by a door opening or closing within the detection
zone.
Advancement in control technology from Aereco has also lead to
the worlds first integrated CO
2 and VOC sensors within grille terminals. Both incorporate
six levels of activation threshold, to ensure the rate of
extraction is suited to its environment. The activation threshold
can also be re-adjusted at any time, (should the environmental
conditions change). The level of pollutant concentration detected,
is shown using an LED display, with green representing levels of
pollutant below the threshold, and yellow representing levels of
pollutant above the threshold. When the pollutant concentration
level rises above the level set, the terminal will open the louvres
to allow maximum permissible airflow, and will continue extracting
at this level for twenty minutes beyond redetection of
concentration below the limit.
Some circumstances may require a nominal amount of manual
control, and Aereco has the response to this. In areas where
additional ventilation over the typical detection range is
required, certain models can be supplied with an impulse switch
function. Terminals are connected to bell button switches, giving
occupants the ability to increase ventilation when required, which
can be particularly useful in kitchens. Aereco also offers a remote
version for increasing the ventilation level to peak airflow. The
terminal incorporates an infrared sensor, activated using a
suitable remote control.
Providing a suitable method of controlled extraction is only
part of an effective ventilation system. Aereco also offers the
Hygro technology in the form of air inlets, to suit both window and
wall installation.
Background ventilation is a necessary feature of a ventilation
system that is often overlooked in terms of its function, when
combined with a mechanical extract system. Conventional air inlets
offer little control over the level of air input. However with
Aerecos Hygro control, the level of air input is adapted to the
occupants requirements on a room by room basis.
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5The purpose of correctly positioning Inlets and Extract units
is to establish and maintain a sufficient rate of air transfer
within the building envelope, and thus ensure good indoor air
quality. To achieve this, air inlets and grilles should be
positioned at points away from the door at a typical height of 1.7m
(to avoid unpleasant draughts).
Internal doors should also be undercut by 10mm (where thick
carpets and floor finishings are fitted this clearance should be
10mm above the finished level), in order to ensure good airflow
between rooms. The undercut will provide a minimum of 7,600mm2 on a
standard width door.
Extract terminals should be installed into, or as close to, the
ceiling as possible to ensure that warm, moist air is extracted.
This should also be positioned away from internal doors, and not
placed directly above a cooker (unless also fitted with a FBE
filter) to prevent damage to the unit from condensing fats /
oils.
In kitchens where a cooker hood is also fitted, this should be
of a kind that filters and circulates the air rather than
extracting. This is because the rate of extraction would be too
great to prevent unnecessary heat-loss.
Extract units using a PIR / CO2
/ VOC sensor should be fitted with the sensor pointing towards
the main area of activity. For example facing the door in a WC, or
facing the cooker / sink in a kitchen.
Installation of air inlets should follow the manufacturers
instructions. Aereco will provide further information regarding the
slot size for window inlets, and wall passage dimensions with the
installation instructions for each specific product. It is
generally advised that on-site inspections are carried out to
ensure that the proposed location is suitable, and to determine
that there are no blockages to the path of the airflow. It is also
required that inlets are sealed in a suitable manner to their
support.
Position of inlets/grille terminals for air transfer
Product selectionType of product Product choice
Quiet environment Noisy environment
WindowsRolling shutters Wall
WindowsRolling shutters Wall
EMM, EHA, EFR EHT
EHA+
Acousticaccessories
EHT+Acoustic accessories
EMM, EHA, EFR EHT
EHA+
Acousticaccessories
EHT+Acousticaccessories
BXC hi BXC h BXC hrc BXC rc
BXC h
BXC i BXC pd BXC p
BXC hp BXC hpd BXC hi
Air inlet
Air inlet
Extract unit
Extract unit
Extract unit
Extract unit
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6Fan selection
Product selection
There are several factors influencing the selection of a fan for
a particular system. Among these factors are; the number of
wet-rooms to be extracted from, whether the system is to be fitted
to an individual dwelling or collectively extract from a number of
dwellings, and sufficient fan power to provide the required number
of air changes.
Aereco has a number of constant pressure / variable volume fan
motors to suit a range particular applications and scenarios.
Although a system would normally be specified and planned by a
designer, this section aims to provide guidance on fan selection
where a designer has not been involved.
The location of the system fan(s) can be determined by the type,
size and layout of the property concerned. Each dwelling type
should be assessed individually.
Typical locations for fan installation include cupboard spaces,
loft areas, or ceiling voids. Where fans are installed within
confined spaces it must be ensured that there is clear space around
the
fan for the final connection of ductwork onto spigots, and for
servicing at intervals specified by the maintenance schedule for
the particular unit.
Once a fan location has been identified, the selection can be
narrowed down based on the units sound pressure levels. When a fan
is located in an area where material construction has poor
attenuation properties, one of Aerecos range of silent units should
be installed.
There are several Aereco fans from which the specifier /
installer can choose, offering a variety of airflow characteristics
and other properties. It should also be ensured that the choice of
unit conforms to current building regulations (Building Regulation
for England and Wales: Approved Document F, Part K Ventilation of
Buildings Scotland, Northern Ireland Technical Booklet K).
Aereco can provide guidance for initial selection from 2-6 wet
rooms, although the exact ventilation provisions should also be
calculated.
Building type Fan units Product choice
Available space in the atticor on terrace
Available place in the inhabitable space
HouseVPH2
(protected place)VAM V2A V4A
Apartments
1 collective fan for several dwellings
or1 whole house fan
per dwelling
VEC 240H VEC 271H
VEC 321H VEC 382H
VAM V2A V4A
(1 per dwelling)
Offices and meeting rooms
1 collective fan for several desks
or1 whole house fan for
several TDA
VEC 240H VEC 271H
VEC 321H VEC 382HVAM
Collective fan
Wholehouse fan
Collective fan
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7L N
230 VACINPUT
12 VAC OUTPUTProduct selection
Fan installation
Aerecos range of DCMEV fans are simple to install. However care
should still be taken to ensure that the construction material the
fan is fixed onto is able to support its weight.
Depending on fan type, the unit is to be attached to its support
using the recommended / supplied fixing brackets. Aereco details
this within the Operation and Maintenance manual for each fan.
Certain models are also capable of being suspended by a cord
from the roofing supports. In some cases it may be necessary to
install the fan(s) onto acoustic / anti-vibration mats to reduce
noise transmission.
In order to carry out servicing, there must be reasonable access
to the unit. Within loft areas and cupboards this should be
achievable without any alterations. However when a unit is fitted
within a ceiling void it would be appropriate to install an access
hatch directly beneath the machines location, with a surface area
large enough for the removal of the casings front cover. With
certain fan(s) this hatch may need to be larger than the front
surface, due to the way the cover is removed.
Aerecos residential ranges of DCMEV units are suitable for
connection to 230 V 50 hz power supply, via a correctly rated fused
spur.
Power Connection
The installer / electrician should first check the electrical
rating label to determine whether an earth connection is
required.
A means of isolating the unit for maintenance purposes must be
provided and it is good practice to locate this near to the fan, or
in an obvious location. Care must also be taken when choosing a
location, to prevent the machine being unintentionally isolated
during normal running conditions.
Grille terminals with electrical boost may also require a power
connection. The PIR and impulse switch boost, can either be powered
via a hardwired supply, or 2x AAA (1.5 V) batteries. CO
2 and VOC type terminals are hardwired only.
When hardwired, a rectifier is always required. This is already
included with the CO
2 / VOC / RC units, and must be purchased separately for other
models. The
rectifier (which also contains an integral 12-3 Vac transformer)
provides an output of 3 Vdc to supply the powered sensors, and
boost facilities, when connected to 12 Vac supply. Certain fans
have an integral 230-12 Vac transformer, while other models do not.
Aereco can supply a stand alone 230-12 Vac transformer where
required.
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8Dont Introduce more bends than necessary.
Allow ducts to be unsupported.
Attempt to fabricate components not suitable for the transfer of
air.
Use flexible duct for the entire installation.
Rush the connections.
Cram flexible duct into small areas where it can be crushed.
Use flexible connections as bends.
Snake ducts unnecessarily
Ducting must be competently installed to ensure minimum air
resistance and leakage within systems. For guidance on air
tightness please refer to HVCA DW/143 document A Practical Guide to
Ductwork Leakage Testing.
In order to minimise pressure loss, rigid duct should be used
throughout with only small lengths of flexible duct used for final
connections, negotiating obstacles or introducing irregular angles
in the duct run. Duct installation must follow the plan as
specified by the designer, (although there may be previously
unanticipated obstacles).
Where the direction of the duct run changes at a 90 angle, rigid
components must be used. It is also appropriate to use rigid
components for shallower bends (e.g. 45 bends), however as not all
angles can be achieved with the use of standardised rigid
components, the use of correctly fitted flexible ducting is
acceptable in such circumstances.
Rigid ducting should be correctly supported using either purpose
made clips or metal banding. Workable duct lengths should be
connected together at floor level before being supported.
Particularly around obstructions. This ensures that the duct can be
suitably sealed. Flexible ducts should be similarly supported,
although extra care must be taken when using banding, as it can
crush the duct and cause restrictions to airflow. Purpose made
clips are therefore recommended.
Lengths of rigid ducting should be connected using duct /
straight pipe connectors or components, and sealed appropriately to
ensure there is no leakage. Ducts should be sealed using tape,
jubilee / speed clamps or sealant. Where sealant is used, a non
hardening variant should be mounted as there may be some slight
movement in the system.
Ducting installation Ducting installation
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9Ducting installation
All ducts must be sealed against leakage, and special care taken
for duct lengths which pass through inaccessible areas, such as
ceiling voids and partition walls. It is also advisable that a
silicone sealant is used rather than duct tape, as this ensures
longevity.
As previously stated, the use of flexible ducting should be kept
to a minimum in order to maximise airflow. Where flexible duct is
used it should be pulled taut to approximately 90 % of its maximum
length. If this is too taut it puts strain on fixings and can
adversely affect duct bends, and if it is not taut enough it can
cause airflow resistance through sagging. The tension applied
should seek to strike a balance between these two extremes.
The sealing of connections to flexible ducting should be via the
use jubilee / speed clamps and neither sealant nor tape alone, as
these do not provide sufficient restraint when the ducting is
pulled taut.
Insulated duct, (flexible or sleeves) should be used where
required for the prevention of condensation on or within ductwork.
This insulation must achieve a thermal conductivity of 0.04 W/mK,
which is characteristically equivalent to 25mm of fibre-glass
insulation. Insulation of ductwork in Aereco DCMEV systems is
required for ductwork which passes through areas which are outside
the insulation barrier of the dwelling. Insulated duct comes in two
formats, standard and acoustic (where the internal bore is
perforated). The acoustic variant should not be used outside the
insulation barrier of the dwelling, as condensation can pass into
the fibre-glass material, and reduce its effectiveness.
Where insulated duct has been installed vertically, it may also
be necessary to install condensation traps. Fire safety is not
covered in this document; however a fire strategy should be applied
with reference to the latest standards and regulations.
Do Ensure ducts take path of least resistance.
Use rigid duct throughout where possible
Avoid unnecessary bends.
Ensure ducts are fixed to the surface securely
and sealed appropriately.
Mechanically fix and tape joints to ensure an airtight seal
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10
Handover
Upon handing over the system to the client, the installer must
provide suitable instruction for maintenance and operation.
Operating and maintenance instructions are provided within the
packaging of Aereco fans and grille terminals. These can also be
downloaded from www.aereco.co.uk.
Instruction must not only be provided in a literary form, but
also in the form of demonstration and advice where appropriate. It
is recommended that the occupier / client is informed of need keep
cross ventilation passages free from obstructions, and settings
which should not be adjusted, in order to maintain the correct
balance of ventilation.
Checklist
Before handing over to the client, it is advisable that the
system is checked and tested to ensure correct operation.
Ductwork should be visually inspected to ensure joints and
fixings are tight and sealed in an appropriate manner to certify
that the system has no defects which are hazardous, or will affect
performance.
All grille terminals should be inspected to ensure shutters can
move freely and that boost functions and sensors (where applicable)
are working correctly. The Hygro should be visually checked to
ensure that that the shutters open correctly when humidity levels
increase. Models with a boost function should be checked in the
test mode (as detailed in the appropriate instruction manual
supplied with each grille).
The positioning and operation of the isolating switch should be
checked. (The fan should only be able to be turned off by the
occupier using the isolation switch).
Once all other checks have been completed a visual inspection of
the fan must be undertaken. After isolating the power to the fan,
the wiring should be checked to ensure connections are secure. The
fan also needs to checked to ensure that it is free of any debris
which could harm the internal working of the unit. After the checks
have been performed and the fans lid has been re-fitted, the power
can be switched on. At this point the fan should be checked for any
abnormal noise, whilst running at both high and low levels of
extraction.
It is advisable to check the airflow with a manometer. The BXC
terminals incorporate a pressure plug which can be used to fix the
Hygro to its minimum position. A reading can then be taken from the
pressure plug and airflow deduced by the conversion table supplied
within the box. Aereco can also provide assistance where
required.
System verification and instruction Installation schematic
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11
Grille termination BXC Extract fan V2A Extract fan V4A Extract
fan VAM Extract fan VPH
Code CodeAVLBXC273 (h) AVLBXC215 (hi) AVLV2A032 AVLV4A336
AVLVAM767 AVLVPH075AVLBXC276 (p) AVLBXC299 (pd)AVLBXC275 (hpd)
AVLBXC401 (CO
2) Characteristics
AVLBXC402 (VOC) AVLBXC404 (RC) Max. airflow: 80m3/hr Max.
airflow: 210m3/hr Max. airflow: 250m3/hr Max. airflow:
300m3/hrAVLBXC406 (hRC) AVLBFX371 (F) Max. pressure: 80 Pa Max.
pressure: 118 Pa Max. pressure: 120 Pa Max. pressure: 130 Pa
Dim.: 390x390x176mm Dim.: 450x450x219mm Dim.: 480x480x240mm
Dim.: 340x335x345mmAirflow characteristics
Humidity controlled InstallationAirflow @ 100 Pa: Max. available
spigots: 4 Max. available spigots: 4 Max. available spigots: 7 Max.
available spigots: 612-70m3/hr: min. position Airflow capacity: 2
extracts* Airflow capacity: 4 extracts* Airflow capacity: 6
extracts* Airflow capacity: 6 extracts*42-120m3/hr: max. position
Installation in inhabitable
space (cupboard, ceiling, etc.)Installation in inhabitable space
(cupboard, ceiling, etc.)
Installation in inhabitable space (cupboard, ceiling, etc.)
Controls Installation in protected non-inhabitable place (attic,
etc.)
Installation in protected non-inhabitable place (attic,
etc.)
Installation in protected non-inhabitable place (attic,
etc.)
Installation in protected non-inhabitable place (attic, etc.)h:
humidity control
i: impulse (switch) Installation in wall on ceiling Installation
in wall on ceiling Installation in wall on ceiling Installation in
wall on ceilingp: pressence (PIR) Installation on floor
Installation on floor Installation on floord: boost delayRC: remote
control Spigots: in the boxCO
2: CO
2 control
Inlet: 80mm dia x 2 Inlet: n/a Inlet: n/a Inlet: 80mm dia x 4
125mm dia x 2VOC: VOC controlF: manually settable Outlet: 100mm dia
x1 Outlet: 125mm dia x1 Outlet: 125mm dia x1 Outlet: 100mm dia
x1
Duct compatibility Accessories125mm dia (up to code 299) Inlet:
80-125mm dia
Code: AVLAEA877Inlet: 125mm dia spigotCode: AVLAEA055
Inlet: 125mm diaCode: AVLAEA808100mm dia (from code 400)**
Bracket** Outlet: 100-125mm diaSpigots available as accessories
Code: AVLCR125100
Installation schematic
* maximum airflow capacity depends oncalculated pressure drop,
figures shown are a estimated average
** please contact Aereco for alternative model codes
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UK Office2B, 4020 MiddlemarchSiskin Parkway EastMiddlemarch
Business ParkCoventry CV3 4SUtel.: 024 7630 7736 fax: 024 7663
[email protected] | www.aereco.co.uk FLY
510G
B_U
K
