To provide heat recovery and ventilation for a single room. With two built-in fans, IV-Twin+ does not need to be paired with another fan elsewhere; it works independently recovering up to 94% of heat from the extracted air to warm up cool air coming in from outside.
Use it on
External walls up to up to 745mm thick (with large wall-sleeve) or 495mm thick (with standard wall-sleeve). Predominantly in kitchens and bathrooms but also living spaces, hotels, office spaces, public rooms, schools, and gyms. Suitable for block, concrete, stone, timber frame, and brick constructions. It should be positioned on an external wall. Minimum compatible wall thickness is 270mm.
The IV-Twin+ is a low-energy single room heat recovery ventilation unit containing two reversible fans that work together to extract and supply air with a heat recovery rate of 94%. With two inbuilt fans, it does not need to be paired with a second unit elsewhere. There are two thermal accumulators for heat recovery, a separating element, two integrated dust filters, a closable inner cover and a weatherproof exterior grill. Combining these features and components provides excellent heat recovery with maximum air flow and low levels of sound emission and transmission of noises from outside within a single room.
Where to use it
Kitchens and bathrooms are the ideal location for the IV-Twin+. It is also suitable for use in offices, schools, gyms or hotels where ventilation with heat recovery is required for a single room (no other paired fan elsewhere is necessary).
The IV-Twin+ can be installed into a 225mm hole, with 2° fall to the exterior. They can be installed in block, concrete, stone, timber frame, and brick constructions. The minimum compatible wall thickness is 270mm. A 495mm or 745mm wall sleeve is available.
The IV-Twin+ must be positioned on the external wall, so its centre is at least 250mm away from any windows or wall edges and at least 450mm away from roof eaves so that the external cover can be slid into position from above. The interior side of the unit must not be covered or obstructed by furniture, fixtures, or fittings.
The IV-Twin+ requires a connection to a controller to supply power and to control fan speed and mode of operation (e.g. heat recovery mode, extraction mode). The IV-Twin+ will use up two connection slots on the sMove controller as there are two fans within the unit.
What it does
The Inventer IV-Twin+ single room heat recovery ventilation unit provides ventilation and heat recovery with very little sound emission and has an air flow rate of 5-23 m³/hour when in heat recovery mode. When doing extraction only, the air flow rate is 10-45 m³/hour.
There are two fans with separate airflow paths within the unit. The fans work in opposite directions to each other, and both will change direction every 70 seconds. One fan extracts warm stale air from inside the building while the other fan supplies fresh air from outside. The warmth of the extracted air is used to heat up one of the ceramic thermal accumulators. After 70seconds the fan silently reverses and the external fresh air from outside is pulled through the warm thermal accumulator heating it up as it enters the building. The fans have an excellent 94% heat recovery rate which is the most efficient of all the Inventer units. This fan must be connected to an sMove controller - the controller supplies the power to the fan and operation and setting changes are done through the controller. It is possible to add a humidity sensor the unit.
While in heat recovery mode, the volume of air is extracted is equal to the volume of air supplied so the air pressure within the room/building does not change.
The IV-Twin+ has a built-in temperature monitor which can detect when incoming air drops below 5°C. To ensure there is sufficient warmth in the heat exchanger to heat the cold inbound air to a comfortable room temperature, the IV-Twin+ automatically begins four extraction cycles to warm up the heat exchanger four times more than normal.
The IV-Twin+ contains two reusable G3 dust filters (one for each fan) that remove dust particles from inbound external fresh air without reducing the airflow-rate. A pollen filter and activated carbon filter is also available as an optional upgrade; these can be used to remove all impurities and allergens from the inbound external fresh air. These “finer” filters will reduce the airflow rate by 25%.
The dust filters should be checked and washed every four months. They can be washed multiple times, but it is recommended to replace them every 12 months. If there are any holes or tears in a filter, it will need replacing immediately.
The wall cover, on the interior of the wall, can be closed to prevent possible draughts when the fan has been switched off. It’s also useful for when external noise is very loud (Roadworks for example) or there are bad odours outside (Farm smells/drains for example). Simply press the cover towards the wall (blocking the hole) to close it and pull it out to re-open.
For optimal use of the IV-Twin+ especially when used in a moisture generation room (bathroom/kitchen for example) we recommend connecting a Humidistat to the sMove controller being used to enable the monitoring and regulation of humidity.
Why we love it
The IV-Twin+ is highly energy efficient (up to 3W) with an A+ efficiency rating. Its sound emission is 14-38 dB (A) from minimum to maximum fan speed. The fan blades have been designed especially for Inventer decentralisation units and engineered to reduce external noise.
The inner cover can be closed if necessary especially useful if there are roadworks outside or hot weather has caused bad odours to occur outside.
Like all Inventer units, there is an integrated wind stabiliser in the IV-Twin+ to ensure the air flow within the building is not affected by strong wind and gusts.
When a humidistat (located in the same room) is connected to the IV-Twin’s sMove controller, both fans in the IV-Twin+ will automatically switch to exhaust mode when a target humidity level (set by the user) is exceeded. This is essential for kitchen and bathroom areas where moisture fluctuations regularly occur. This will quickly and efficiently remove the unwanted moisture to ensure the highest levels of indoor air quality can be achieved.
The built-in G4 dust filters can be easily removed, washed, and refitted.
It has a modern interior cover and a stylish exterior protection hood.
How it works
The IV-Twin+ is the only Inventer unit with two built-in fans Each fan has a separate ceramic heat exchanger. While extracting air, these absorb heat from the warm, extracted air as it passes through. After 70 seconds of extraction, the ceramic material is fully heated, and the fans silently reverse direction. When fresh air from outside passes in through the heat exchanger in the opposite direction, the ceramic material transfers heat back to the incoming air warming it up as it enters the building.
The IV-Twin+ must be connected to a sMove controller. Because there are two fans in each IV-Twin+, an s4 controller can operate two IV-Twin+ units and an s8 can operate up to four IV-Twin+ units.
The IV-Twin+ can be used as part of a larger decentralised system. For example, one IV-Twin+ unit can be connected to an s4 controller along with two other paired fans (for example 2 x IV14-Zero). Each controller used creates a “zone” that can be independently controlled. You can have more controllers connected to pairs of fans or to more IV-Twin+ units to create additional zones as needed.
- 94% heat recovery
- Quiet fan. 14-38 dB (A)
- 0.5-3W energy consumption
- Reduces external noise by 45-56 dB
- 5-year guarantee with fan
- 30 year guarantee with thermal accumulator
- Built-in temperature sensor
- Unaffected by strong wind outside
- Stylish stainless steel exterior hood
- Closable inner cover
- Inventer's most efficient unit with 94% heat recovery
- Energy efficient 0.5 - 3W fan lowers running costs and carbon emissions of the building to help make an active contribution to the environment
- Can be connected to a humidity sensor
- Two separate built-in G4 dust filter can be cleaned and reused many times.
- Additional filters are available to provide total control of all allergens entering the building and ensure the highest levels of indoor air quality can be achieved
- Closable inner cover prevents unwanted draughts when the fan is switched off and reduces noise or odours from outside
- Below 5° C outside, the heat recovery cycle is adapted to recover more heat and ensure cold air is not supplied to the building.
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Key Technical Data
Installation GuideFind an installer
Turn the power off during electrical works. All electrical connections must be carried out by a qualified professional. Seek professional advice for planning and installation of all electrical works.
The IV-Twin+ receives its power from an Inventer sMove controller. This should be installed first by following the controller’s installation guide. The wire from the controller must be long enough to reach the connector on the fan’s power cable. Depending on the wall thickness, this connector could be inside the hole, so please ensure the wire is long enough to reach right to the back of the hole.
When installed on an external wall, a 225mm wide hole will be required. The hole should have a 2° fall to the outside to allow any condensation to run off to the exterior. In walls made from brick, concrete or stone, this should be cut with a 225mm masonry core drill.
For newbuilds, a wall mounting block is available. This block can be incorporated into the brickwork of the building for easier installation without the need for core drilling. It incorporates insulation and a 2° slope.
The best position for the fan on the wall should be worked out in advance before drilling. The fan must be positioned so the centre of the fan, internally or externally, will be at least 250mm from the edge of a window or ceiling and at least 450mm from the eaves of the roof. This 450mm eaves clearance provides enough space to slide the exterior grille downwards into position on the exterior wall. The internal end of the fan should be situated away from radiators, thermostats, sensors and heat sources and should not be obstructed by furniture, fixtures or fittings. Locating the unit near sensitive artworks/paintings should be avoided to avoid any damage caused by the drying effect of near constant air movement.
Once a suitable hole with a 2° fall to the outside has been created, the wall-sleeve can be cut to length. The wall-sleeve has a notch at one end. This notched end should be on the interior side of the hole. You must cut the other end. The required length of the wall-sleeve is equal to the thickness of the wall plus an extra 10mm. The aim is to have the wall-sleeve protrude by at least 10mm at the exterior end outside.
Hint: You may find it easier to judge the length required by fitting the pipe into the hole and aligning the interior end flush with the wall (consider any internal plaster/finishes to be added later and adjust as necessary). Then make sure the wall-sleeve has a 2° slope towards the exterior. You may need to use the supplied wedges to align and secure the wall-sleeve at the correct 2° incline. From the exterior, draw round the protruding pipe with a pen or pencil to mark the wall level on the sleeve. You could use a spacer or your finger between the pen and the wall to draw the line 10mm away from the wall surface, or you can just mark the wall line, remove the sleeve from the wall and draw a second line on the sleeve 10mm further along. Once you have a suitable line to mark the thickness of the wall including the extra 10mm, cut the sleeve and reinsert it into the wall replacing the wedges as needed.
After the wall-sleeve is cut to length and inserted into the hole, the wall-sleeve should be rotated so the notch is towards the bottom and near where the power wires will be. The IV-Twin+ is supplied with a white cylindrical insert. This can be inserted into the wall-sleeve to temporarily block the hole and prevent draughts while you continue the installation.
The Wall-sleeve should be a snug fit in the hole and sealed airtight at both ends. It should be placed so that the screw holes in the wall sleeve are in facing towards the interior to later fit the inner cover. To help centre the wall-sleeve in the hole, the supplied wedges can be used (at either end) to adjust the position of the wall-sleeve and make sure the wall-sleeve has at least 2° of slope to the outside. The wedges can remain in place. Where any wedges protrude from the wall, this can be cut with a sharp knife so it is flush. Seal gaps of up to 6mm between the wall-sleeve and wall with Pro Clima Orcon F airtight sealant. For bigger gaps of up to 20mm, use Aerosana Visconn Fibre. If any gaps exceed 20mm, fill with mortar, leave it to set then seal all around with Orcon F or Aerosana Visconn Fibre. Alternatively, an expanding foam filler can be used to fill gaps around the wall-sleeve. Once set, the foam and the wedges can be trimmed flush to the wall. As this material can crack over time and may not provide a permanent airtight seal, the foam must also be covered over and sealed with Aerosana Visconn Fibre to remain airtight for the lifetime of the building.
If the wall has no plaster or render on it and will be plastered or rendered later, a pair of 180-220mm Pro Clima Roflex Solido airtight grommets can be used to seal either end of the wall-sleeve to the wall. This grommet is stuck to the surrounding masonry then plastered over to finish.
The external weather protection hood is installed next. The external baseplate should be orientated so the horizontal grill section is at the bottom. A spirit level should be used to make sure everything is horizontal then holes can be marked and drilled (to a depth of 50mm) with an 8mm drill bit then the supplied wall plugs can be inserted.
The foam weatherproofing tape should be applied around the outside edge on the back of the baseplate then the baseplate can be screwed to the wall. Use the supplied screws and washers. The outer grill will then slide down from above fit over the baseplate and complete the external part of the installation.
Work now continues from the interior side. The temporary insert used to plug the wall-sleeve must now be removed. The ceramic honeycomb thermal accumulator is inserted next. Hold the handle on the accumulator and push all the way to the back of the wall-sleeve. Then insert the fan with the wire facing toward the interior of the room. Rotate the fan, if necessary, to align the wire location with the notch in the wall-sleeve. Depending on the thickness of the wall, you might need to connect the fan to the power supply (the wire from the controller) before inserting the fan all the way in the wall-sleeve.
The inner cover can now be installed. The cover has two parts: a baseplate and a smooth top cover. The smooth top cover needs to be separated from the baseplate by pressing the small release buttons at each corner. The power wire (from the controller) should now be connected. The base plate should be fixed to the pre-drilled holes in the wall sleeve using the screws provided. The filter is then inserted into the baseplate. The smooth top cover is then pressed over the filter onto the baseplate and clipped into place.
Dust filters should be checked and washed every four months. They can be washed multiple times but they are recommended to be replaced every 12 months. If there are any holes or tears, they will need replacing immediately.