MAKING MODERN LIVING POSSIBLE

Installation Guide

Duct Systemfor Danfoss Air Units

www.heating.danfoss.com

Danfoss A/S is not liable or bound by warranty if theseinstructions are not adhered to during installation or service.

The English language is used for the original instructions.Other languages are a translation of the original instructions.(Directive 2006/42/EC)

© 2011 Copyright Danfoss A/S

1 Installing Valves

Placing the valvesStart by deciding on the location of the valves, using the enclosedtechnical drawing as a guideline. If the drawing indicates a valve inthe path of e.g. electrical wiring, water ducts or wooden joists, thefvalves can of course be moved.

Avoid placing air diffusion valves above places where people maybe located for long periods, such as sofa, bed, dining table, etc. If awood-burning stove is present, it is best to place the air diffusionvalve nearby.The extraction valves are meant to remove moist ”contaminated”air. They should therefore be placed as close as possible to thesource, e.g. above washbasins, in shower cabinets, etc.

Drilling holes in the ceilingA hollow drill should be used for making the holes for the valves.Use the following drill sizes:

▪ Ø 100 mm valves: hollow drill Ø 108 mm.▪ Ø 125 mm valves: hollow drill Ø 133 mm.

Avoid damaging the damp course unnecessarily and always re-member to repair it with weatherproof tape from the ceiling sideafterwards.The size and shape of the valves varies depending on the air direc-tion and volume.

Supply air valve Extract air valve

Mounting the valvesFix the valve bayonet socket to the ceiling. For gypsum ceilings,place a wooden plate on the back for the screws to bite into.

200

200

If the duct needs to pass through insulation, we recommendmeasuring the insulation section and installing a duct sectionalong a suitable length of the bayonet socket (VGU or VGM). Use aNPU connection nipple to connect the VGM and the duct section.

Installation Guide Duct System

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2 Installing Ducts

To achieve the highest operational efficiency, the duct systemshould be installed as compact as the building construction allowsby keeping the duct sections as short as possible and using as fewbends as possible.If the ducts are located on the loft floor, they can be secured usingduct clips.

Duct clip

Duct clips can also be used if the duct system is suspended fromthe roof, using UV fixing hangers, if required.

Example of duct installations

Note!

▪ the ducts must not rest on the valves or hang in the roof ter-minals.

▪ place a soft material between the duct and the rafters/ductclip to avoid vibration noise.

▪ avoid installing damaged products (e.g.dented ducts), as thismay reduce the performance of the system and can result inleaks.

▪ the ducts should be placed in the insulation, in order to mini-mise heat loss (see page 5 "Insulating the Duct System").

Adjusting the ductsUse a hacksaw or angle grinder to adjust the ducts.Remove all sharp edges on the duct to avoid damaging the rubberseals on the fitting parts.

Adjusting duct length

Always use appropriate protective equipment (i.e. protective gog-gles, ear defenders, etc.).

Connecting the duct systemPush the connector into the duct, until the stopsick is reached(slightly turning the connector will make the assembly easier).

��

T-connector

Fix the connectors to the duct with at least two self-tappingscrews or pop rivets (three for ducts of Ø140 mm or more). Makesure that the safe rubber strips are not damaged. In case of incor-rect assembly, screw/pop rivet holes should be sealed up.

Assembling T-connector and ducts

The standard length of ducts is 3 metres. To connect two ducts,use an NPU nipple with a rubber strip.

NPU nipple

To reduce a branch, use a TCPU T-section.To reduce the main duct, use a RCFU reduction.

Ø 1

25

Ø 100

Ø 1

00

TCPU RCFU

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Crossing ductsIf two ducts need to cross, we recommend installing the duct thatruns along the beam underneath the duct crossing it to reduceheat loss.

30˚

30˚

30˚

Crossing ducts

To get your duct down into the insulation as quickly as possible,we recommend the solution illustrated.

30˚

70

600

1200

SLU

SR

SR

BU

Connection to unit (side view) Connection to unit (top view)

Connection between ducts and unitIt is important that all 4 flanges are connected to the ducts with aflexible connection, so that potential vibrations are not transferredfrom the unit to the ducts system.

Avoid bending the flex pipe as this will add to an increased pres-sure loss in the system. When mounting, the flex pipe should bestretched as far as possible – without deforming the pipe.It is recommended to use an insulated flex pipe type THISOL.Mount hose clamps around the outer layer of plastic in order toensure air tightness.

Insulating the duct systemIt is important that the duct system is insulated correctly.The supply and the extract must as minimum be covered by 100mm of insulation. It is recommended to use two layers of 50 mmpaper or foil covered lamella mat mounted with staggered joints.

Insulation of ducts

The fresh air intake and the exhaust must as minimum be coveredby 30 mm of insulation to protect against condensation.

If a preheating or geothermal surface is present, the fresh air in-take must as minimum be covered by 100 mm of insulation.50 mm of insulation is adequate for sound dampers, as they al-ready have 50 mm of insulation.Make sure that the insulation is fixed tightly around the ducts.

Incorrect insulation

If possible, the ducts can be run in or under the attic insulation.

Ducts in attic insulation

If steel wire is used to fasten the insulation, make sure that the in-sulation is not deformed or broken by the wire.

Note! The above should be considered as recommendations only. Al-ways follow any country-specific regulations.

Sound DampingSound damping the duct system is a very important element inachieving the general feeling that you have the perfect indoor cli-mate. The noise in a ventilation system comes primarily from theunit’s ventilators. This noise can be propagated throughout theduct system and out into individual rooms unless there is propersound damping. It is therefore also very important that silencersare positioned correctly in the duct system.There are several methods of sound damping, e.g.:

The silencer positioned directly after the unit, before the main ductbranches out (sound damper effective on entire system).

Two silencers positioned on each side of theT-section, beforebranching to a room.

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As well as damping the noise from the ventilators, it is importantto ensure that noise does not propagate from room to room, i.e.where noise runs through the ventilation ducts from room toroom. To avoid this, install a small silencer on the branch to therooms that you want to damp.For room-to-room sound damping, use SLU-100-300 andSLU-125-300, depending on the dimension of the branch.

Roof TerminalsRoof terminals/wall grills and roof ducts are the outside visiblepart of the ventilation system. If possible, they should therefore beadapted to the architectural style of the house.The roof terminals should be placed at least 3 metres apart hori-zontally or 1 metre apart vertically, always with the discharge ter-minal at the top.Avoid positioning the discharge lower than the top edge of thetop window and closer than 1 metre to the nearest window.It is recommended to place terminals/grills on a north- or east-fac-ing surface to achieve the best and most comfortable operation ofthe system.If the roof terminal is installed on a tiled roof, we recommend us-ing a pre-insulated Lindab GISOL roof duct.

We also recommend using Lindab SBG installation fittings and aLindab MG membrane duct for a correct finish against the subroof.

1 m

3 m

3 m

3 Adjusting Valves

The following are guideline settings only.

Adjusting Supply ValvesStart by fully closing the valve (not too tight!). Then open the valvethe number of times indicated in the diagram, which is providedwith the assembly drawing of the ducts system.

+

Pos.

Adjusting Extract ValvesStart by setting the valve to position 0, which in practice meansopening the central cone so the middle of the cone is in line withthe frame.

+

÷

Po

s.

Rotate the cone the number of times indicated in the diagram:+ 5 = anti-clockwise 5 times– 5 = clockwise 5 times

anti-clockwise clockwise

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Installation Guide Duct System

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Installation Guide Duct System

Danfoss A/SHeating SolutionsHaarupvaenget 118600 SilkeborgDenmarkPhone:+45 7488 8000Fax: +45 7488 8100Email: heating.solutions@danfoss.comwww.heating.danfoss.com

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to productsalready on order provided that such alterations can be made without subsequential changes being necessary in specifications already agreed. All trademarks in this material are property of the respectivecompanies. Danfoss Heating Solutions and the Danfoss Heating Solutions logotype are trademarks of Danfoss A/S. All rights reserved.

VIFYB102 Produced by Danfoss Heating Solutions © 11/2011