Nuaire Flatmaster (Standard PIV Unit for Flats & Apartments)

Health & Safety Considerations

Confirm safe access, stable footing and good lighting before you begin. Wear eye protection and a dust mask when drilling the external wall, and gloves when handling sharp metal grilles or ducts. Treat concealed services as live until proven otherwise and use a detector to check for hidden cables and pipes. Do not core-drill near gas flues, boiler terminals or extractor outlets. Keep the unit and ductwork clear of heat sources and do not obstruct any fire barriers. Work methodically, keep the area tidy, and avoid working alone in hot or very cold conditions. Electrical work must be completed via a suitably rated isolator by a qualified electrician.

Site Preparation

Choose a location on or near an external wall where the unit can draw in outside air through a short, direct duct. The usual position for the internal supply grille is high on a central hallway wall, aimed to throw air along the ceiling for even mixing and to avoid draughts. Check there is enough space for the casing, for the intake duct to pass through the external wall, and for the supply grille to be oriented correctly. Plan the route for the mains spur and discuss the cable run with your electrician. Decide whether you will use 100mm circular duct or 121×60mm rectangular duct and confirm that your chosen wall can accommodate the required core hole or slot. Ensure the external grille location is free from exhausts, bin stores and local pollution sources, and that there is sufficient clearance for a weather cowl.

Limitations And Good Practice

Flatmaster supplies filtered outside air into the dwelling at low, continuous rates. It is not an extract system and must not be connected to bathroom or kitchen extract ducting. Keep the intake duct as short and straight as possible, seal every joint airtight, and slightly fall the duct towards the outside so any incidental moisture drains outwards. Fit a weather-protected external cowl with insect mesh and seal it to the wall to prevent water ingress. Do not mount the unit where furniture will block the supply path. Leave a small clearance around the casing so the cover can be removed for filter changes. If you intend to include an optional boost switch, agree the position and wiring with your electrician before fixing the unit.

Step-By-Step Installation

1. Make The Area Safe: Isolate any circuits you may encounter, verify the drilling zone is free of services using a detector, and mark out the unit footprint and the intake duct position on the external wall.
   
   

2. Core-drill The Intake Opening: Drill a clean 100mm hole for circular duct, or cut an opening for 121×60mm rectangular duct, aiming for the shortest practicable route straight through the wall. Angle the hole very slightly to the exterior to encourage any incidental moisture to drain outwards. Deburr and clean the opening.
   
   

3. Fit The External Grille Or Cowl: From outside, offer up the weather cowl with insect mesh, mark fixings, drill and plug as required, then seal the back face with a continuous bead of suitable exterior sealant. Fix the cowl square and tight to the wall to prevent water ingress.
   
   

4. Insert And Seal The Duct Sleeve: Cut the duct to length so it is flush or just proud inside, and fully home within the external cowl spigot outside. Seal around the sleeve both inside and out so there are no air leaks. Avoid crushing the duct and keep the bore clear.
   
   

5. Mount The Unit On The Internal Wall: Offer the backplate to the wall, check it is level, mark and drill fixings, then secure with appropriate plugs and screws for the substrate. Leave enough clearance to remove the front cover for maintenance.
   
   

6. Connect The Intake Duct: Push the internal end of the sleeve fully onto the unit’s intake spigot and secure it airtight with the supplied clamp or a suitable band. Check that the joint is fully seated and that there are no gaps.
   
   

7. Fit The Internal Supply Grille: Position the grille high on the wall, aligned with the unit outlet, and secure it so that the louvres throw air along the ceiling rather than directly at occupants. Adjust the louvre angle to encourage mixing without draughts.
   
   

8. Provide The Power Point And Connect: Fix the local isolator and any control module position agreed during preparation. Your qualified electrician should now complete the fixed wiring, connect the unit, and test for safety. Do not energise until all covers are in place.
   
   

9. Commission The Airflow: With power restored, set the fan speed to suit the property size and moisture load. Check for a gentle, even discharge from the supply grille, verify that the external cowl is secure and unobstructed, and listen for smooth, quiet operation. If an optional boost switch has been installed, test that the unit responds correctly and reverts to background operation after use.
   
   

10. Finish Neatly: Seal around penetrations where needed, tidy the work area, and label the local isolator clearly. Provide any touch-up decoration around the grille and ensure the external cowl sealant is dressed for weathering.

Handover And Everyday Use

Flatmaster runs continuously in the background to dilute indoor humidity and everyday pollutants. Day-to-day adjustment is not required once the speed has been set.

For best results, do not block the internal supply grille, keep internal doors ajar where practical to aid circulation, and continue to use bathroom and kitchen extracts in the normal way. If a boost switch has been fitted, use it for short periods when you need a temporary increase in airflow.

Maintenance And Replacement Filters

Keep the internal supply grille free from dust with a light vacuum or soft brush during routine cleaning. Replace the Flatmaster Filter annually to maintain airflow, energy efficiency and hygiene.

To replace the filter, isolate power at the local spur, remove the front cover, withdraw the used filter, wipe the internal surfaces with a clean, dry cloth, fit the new Flatmaster Replacement Filter fully home, refit the cover, and restore power.

Do not wash or blow out the used filter, this can damage the media and reduce performance. Periodically check the external cowl and insect mesh and clear any debris such as leaves or lint.

Troubleshooting

If airflow feels weak, first clean the internal grille, then check that the external cowl and mesh are not blocked and that the intake duct is not crushed or loose at either joint.

If condensation or a musty smell returns, the usual causes are a clogged filter, an obstructed cowl, or the fan set too low. Replace the filter, clear obstructions and increase the speed slightly, then allow several days for the indoor environment to stabilise.

If unusual vibration or noise is heard, confirm that the unit is firmly fixed to the wall, that no cable or duct is touching the fan, and that the grille louvres are not whistling due to being fully closed. Rattles are commonly caused by loose screws or a poorly seated cover.

If the unit will not run, check the local isolator and protective fuse, then ask your electrician to verify the supply.

Aftercare And Best Results

Leave the speed as commissioned, plan for an annual replacement filter, and keep both the internal grille and the external cowl clean. Pair the system with sensible ventilation habits. Use kitchen and bathroom extracts during moisture-producing activities, keep trickle vents open where fitted, and heat the home steadily in colder weather.

These simple practices, together with the Flatmaster, provide reliable control of condensation and a consistent improvement in indoor air quality for properties without a loft space.

Q) What is the Nuaire Flatmaster and how does it work to control condensation in homes without a loft?

A) Nuaire Flatmaster is a compact, wall-mounted Positive Input Ventilation unit designed specifically for properties that do not have a usable loft. It draws fresh air from outside through a weather-protected grille, filters it inside the unit, and supplies it gently to a central area such as a hallway. This creates a slight positive pressure that encourages moist, stale indoor air to drift out through natural leakage paths and existing extracts. By steadily diluting humidity from bathing, cooking and occupancy, surfaces are less likely to drop below the dew point, so window streaming and damp patches reduce. The filtered background supply also dilutes everyday pollutants and odours, making the whole dwelling feel fresher. Flatmaster achieves this with very modest electrical demand, so it is economical to run continuously.

Q) How is Nuaire Flatmaster different from a loft-mounted PIV such as Drimaster?

A) Both products use Positive Input Ventilation to reduce indoor humidity and improve air quality, but they are designed for different building layouts. A Drimaster-type unit sits in the loft and supplies filtered loft air to the landing, so it suits houses and bungalows with loft spaces. Nuaire Flatmaster is purpose-built for flats, apartments, basements and other properties without a loft, drawing its supply directly from outside through the external wall. The casing, spigot positions and duct choices on Flatmaster make through-wall installation straightforward, with either round or rectangular duct options. Commissioning is similarly simple, with speed selection matched to the property size and moisture load. In short, Flatmaster brings the same PIV benefits to dwellings where a loft source is not available.

Q) Where should the Nuaire Flatmaster be installed and where does the internal supply grille go?

A) The unit is mounted on or near an external wall so it can draw fresh air through a short, direct intake duct. Inside the dwelling, the supply grille is usually fitted high on a central hallway wall, oriented so its louvres throw air along the ceiling to promote mixing without noticeable draughts. Keeping the supply path clear of large furniture helps the gentle background flow reach adjoining rooms through door undercuts or slightly ajar doors. During planning, confirm there is space for the casing and that the front cover can be removed easily for filter changes. A short, straight duct route minimises pressure loss and noise, while an airtight seal at all joints preserves efficiency. Good positioning and louvre orientation are key to quiet, unobtrusive performance.

Q) Which types of properties benefit most from the Nuaire Flatmaster?

A) Nuaire Flatmaster is intended for dwellings that lack a loft supply route yet suffer from condensation and musty odours, such as flats, apartments, maisonettes, basements and cellars. It is also valuable in mixed-use buildings and conversions where a loft-mounted unit cannot be fitted or where through-roof penetrations are undesirable. The unit’s compact dimensions and versatile spigots make it suitable for many wall constructions, including solid walls and cavity walls, provided a weather-protected outside grille can be fitted. Landlords and housing providers use Flatmaster in retrofit programmes to reduce mould complaints and maintenance call-outs. Owner-occupiers benefit from set-and-forget operation with low running costs and minimal disruption at install. As with any ventilation system, it complements, rather than replaces, good local extraction in kitchens and bathrooms.

Q) Will Nuaire Flatmaster stop black mould and how long before I notice an improvement?

A) Black mould thrives where surfaces are repeatedly wet from condensation. By introducing a continuous supply of filtered outside air, Nuaire Flatmaster steadily lowers indoor humidity and encourages damp, stale air to move out, so surfaces remain drier. Many homes see rapid benefits, such as less window streaming in the morning within days, followed by progressively drier corners and reduced musty odours over several weeks. Visible mould already present should be safely removed as part of the process so clean, dry surfaces can be maintained. Pairing the Flatmaster with sensible heating, open trickle vents and consistent use of kitchen and bathroom extracts delivers the most reliable outcome. Improvement timelines vary with occupancy, moisture load and property leakage, but the trend is towards a drier, healthier environment.

Q) How energy efficient is the Nuaire Flatmaster and what are typical running costs?

A) Nuaire Flatmaster is designed for continuous background service with modest power consumption, typically around 3.1 to 9.4 watts depending on the selected speed and installation conditions. Because electrical demand is low, day-to-day running costs are small compared with the damage and redecoration costs caused by persistent condensation and mould. Selecting the lowest speed that controls moisture effectively provides the best balance of efficiency and performance. Keeping the intake duct short and airtight, ensuring the grille is not obstructed and replacing the filter annually help maintain low energy use. An optional boost switch can be used for short periods when extra airflow is desired, without significantly affecting overall running costs. In most homes, Flatmaster’s consumption is comparable to a low-wattage appliance left on continuously.

Q) Is Nuaire Flatmaster quiet in everyday use and what affects noise levels?

A) When installed to best practice, Nuaire Flatmaster provides unobtrusive background ventilation. Low, steady airflow and a correctly oriented grille give a soft discharge across the ceiling rather than a noticeable jet. Perceived sound is influenced by installation quality; short, straight duct runs reduce air noise, and airtight joints prevent whistling. The grille louvres should be set for free discharge along the ceiling, not fully closed, which can create hiss. Externally, a well-fitted cowl with intact insect mesh helps prevent wind noise or vibration. If an unusual sound appears, it commonly points to a loose fixing, a poorly seated cover or a partially obstructed duct that can be corrected quickly.

Q) What filtration does the Nuaire Flatmaster use and how often should the filter be changed?

A) The unit includes a replaceable filter that removes dust and airborne debris from the outside air before it is introduced to the dwelling. Under typical domestic conditions the filter should be replaced annually to preserve airflow, energy efficiency and hygiene. In dustier environments, after nearby construction, or where the dwelling is close to busy roads, a more frequent check is sensible. The change procedure is simple: isolate power at the local spur, remove the front cover, withdraw the used element, wipe internal surfaces with a clean, dry cloth, fit the new Flatmaster replacement filter fully home, refit the cover and restore power. Do not wash or blow out the old filter, as this damages the media and reduces effectiveness. Keeping the internal grille free of dust with a light vacuum helps the new filter work at its best.

Q) Can Nuaire Flatmaster be used in basements or cellars and what should I consider first?

A) Yes, Nuaire Flatmaster is widely used in lower-ground spaces to reduce damp odours and stabilise humidity by supplying a steady flow of filtered outside air. For basements, the key considerations are a suitable external wall for the intake, clear siting for the internal grille, and a duct route that keeps the intake sleeve short and slightly sloped to the outside to shed incidental moisture. The external cowl should be positioned where it is protected from standing water, splashing and local pollution sources, and fitted with insect mesh. Combining Flatmaster with appropriate building repairs and dewatering measures is important where structural damp or water ingress is present. Consistent background supply ventilation, together with local extraction where required, helps keep occupied basements fresher and more comfortable.

Q) What duct sizes and configurations does the Nuaire Flatmaster support for through-wall installation?

A) Nuaire Flatmaster accepts either 100 mm circular duct or 121 by 60 mm rectangular duct, allowing flexibility to suit the wall construction and available space. The unit can be configured for left-hand, right-hand or rear air paths, which simplifies internal routing and positioning. A short, direct run through the external wall is preferred to minimise pressure loss and sound. All duct joints should be sealed airtight and the sleeve should be cut to length so it sits fully home at the external cowl and meets the unit’s intake spigot cleanly indoors. A slight fall towards the exterior helps any incidental moisture drain outwards. Careful cutting, deburring and sealing of the wall opening ensure a neat, durable installation.

Q) How should I site and weatherproof the external intake grille for Nuaire Flatmaster?

A) Choose a location clear of exhausts, boiler flues, tumble dryer outlets, bin stores and other local pollution sources so the intake air is as clean as possible. Fit a weather cowl with insect mesh, square and tight to the wall, and seal the back face with a continuous bead of suitable exterior sealant to prevent water ingress. The through-wall sleeve should be fully home in the cowl spigot and sealed around both internally and externally for airtightness. A very slight fall towards the outside encourages any incidental moisture to drain away from the unit. Periodically check the cowl and mesh for leaves or lint and remove debris as part of routine upkeep. Good siting and sealing are critical to long-term performance and quiet operation.

Q) How does Nuaire Flatmaster work alongside bathroom and kitchen extract fans and trickle vents?

A) Nuaire Flatmaster provides the steady, filtered background supply that keeps humidity and pollutants diluted throughout the day, while local extract fans remove short-term peaks at source. Keep kitchen and bathroom extracts in good order and use them during and after moisture-producing activities. Leave trickle vents open and maintain door undercuts so the gentle hallway supply can migrate into rooms and older air can drift towards extracts. Heating steadily in colder months helps keep surfaces above the dew point, complementing the ventilation strategy. Used together, background PIV and local extraction deliver robust control of condensation and general freshness with very little daily intervention. This combined approach is widely recommended for retrofit and refurbishment programmes.

Q) What does a typical Nuaire Flatmaster installation involve from start to finish?

A) The installer first confirms a safe, service-free drilling zone and marks out the casing footprint and intake position. A clean 100 mm core hole, or a rectangular slot for 121 by 60 mm duct, is created straight through the external wall with a slight fall to the outside. The weather cowl is fixed and sealed externally, the duct sleeve is inserted and sealed, and the unit backplate is levelled and secured indoors with appropriate fixings. The sleeve is pushed fully over the unit intake spigot and clamped airtight, and the internal supply grille is set high on a central wall with louvres aimed along the ceiling. A qualified electrician installs a local isolator, completes the fixed wiring and tests for safety before power-on. The fan speed is commissioned to suit the property and, if fitted, an optional boost switch is tested before the area is made good.

Q) Does Nuaire Flatmaster have a manual boost option for busy periods or quick freshening?

A) Yes, Nuaire Flatmaster can be supplied with or connected to an optional remote boost switch that temporarily increases airflow when you want a little extra ventilation. This is useful during gatherings, after drying clothes indoors or when you simply want to clear indoor air more quickly. The switch position should be agreed during installation, typically in an accessible hallway location, and a qualified electrician will complete the wiring. Boost is intended as a short-term assist, with the unit returning to its background setting afterwards. Using boost sparingly helps keep energy use low while preserving the constant baseline dilution that controls condensation. If you do not need manual boost, Flatmaster will operate effectively as a set-and-forget system at its commissioned speed.

Q) What routine maintenance does the Nuaire Flatmaster need to stay effective and efficient?

A) Routine care is straightforward. Keep the internal supply grille free from dust with a light vacuum or soft brush so the discharge pattern remains even and quiet. Replace the filter annually to maintain airflow, energy efficiency and hygiene, following the simple isolate, remove, replace procedure. Periodically check the external cowl and insect mesh for debris such as leaves, lint or insects and clear them to maintain a free intake. Visually confirm that the intake sleeve and indoor joints remain airtight and that the front cover is properly seated. If your property’s moisture load changes, for example after renovation or increased occupancy, the commissioned speed can be reviewed and adjusted to suit. These simple steps preserve performance and reduce the likelihood of condensation returning.

Q) What troubleshooting steps should I take if the Nuaire Flatmaster seems less effective?

A) Start with the basics: lightly vacuum the internal grille and check that doors are not blocking the supply path. Inspect the external cowl and mesh for obstructions and ensure the intake sleeve has not become crushed or dislodged. If airflow feels weak or a musty odour returns, the most common causes are a clogged filter, an obstructed cowl or a fan speed set too low; replacing the filter, clearing debris and increasing speed slightly usually resolve the issue. Confirm that all joints remain airtight, as small leaks can reduce delivered flow and create noise. If vibration or rattling is heard, check for loose fixings or a poorly seated cover and tighten as required. If the unit will not run at all, verify the local isolator, protective fuse and supply, then consult a qualified electrician or your supplier.

Q) What are the main limitations of the Nuaire Flatmaster and when might it not be suitable?

A) Nuaire Flatmaster is a supply-only system that relies on introducing filtered outside air at a low, continuous rate. It must not be connected to bathroom or kitchen extract ducting, nor used where an external intake cannot be sited and weatherproofed correctly. The unit will not resolve liquid water ingress, plumbing leaks or structural damp, which require direct repair. It should not be installed where furniture blocks the supply path or where the front cover cannot be removed for filter changes. Intake locations close to exhausts, boiler flues or heavy pollution sources are unsuitable. In unusual layouts or exceptionally airtight flats, the commissioned speed and grille orientation may need more careful adjustment to ensure free movement of air into rooms.

Q) Does the Nuaire Flatmaster improve indoor air quality beyond controlling moisture and condensation?

A) Yes, Nuaire Flatmaster provides a continuous, filtered background supply of outside air that dilutes everyday indoor pollutants from cooking, cleaning, furnishings and occupancy. This gentle renewal helps reduce stale odours and can make spaces feel fresher, particularly where opening windows is impractical due to noise, security or weather. Because the system runs continuously, it smooths out peaks and troughs in pollutant levels that arise from daily activity. The result is a more stable indoor environment with less stuffiness and better perceived comfort. Used alongside well-maintained local extracts and sensible housekeeping, Flatmaster supports a healthier baseline for occupants. Many housing providers specify it for both condensation control and wider air quality benefits in retrofit programmes.

Q) What certification and warranty support come with the Nuaire Flatmaster?

A) Nuaire Flatmaster carries independent certification that confirms its suitability for purpose when designed and installed correctly, including typical performance up to 22 litres per second at free air with very modest electrical demand. The product is supplied with a comprehensive warranty of five years parts and labour followed by four years parts, reflecting durable construction and long-term service expectations. To maintain warranty confidence, install to the manufacturer’s guidance, commission the correct speed and carry out annual filter changes. Keeping a simple record of installation date, speed setting and filter replacement helps future maintenance. In the unlikely event of an issue, established trade networks provide specification advice, spares and aftercare. This combination of certification and support underpins Flatmaster’s use in managed housing portfolios and private homes alike.

Q) What practical tips will help me get the best results from the Nuaire Flatmaster day to day?

A) Leave the fan at its commissioned speed and keep the supply grille clear so the gentle flow can spread along the ceiling. Use kitchen and bathroom extract fans during and after moisture-producing activities to remove peaks at source. Keep trickle vents open and maintain door undercuts or leave doors slightly ajar to aid circulation into rooms. Heat steadily in colder months to keep surfaces warmer, which complements the background dilution provided by Flatmaster. Replace the filter annually, and glance at the external cowl occasionally to clear any leaves or lint. If you have an optional boost switch, use it for short periods when you want a temporary uplift, then let the unit return to its quiet background setting.

Q) How do I plan the siting of the Nuaire Flatmaster intake and internal grille to avoid draughts?

A) Position the internal grille high on a central hallway wall and set the louvres to throw air along the ceiling rather than towards occupants, which promotes quiet mixing and avoids draughts. Keep at least a small clearance around the grille so the discharge is not blocked by cupboards, shelves or door heads. Externally, choose an intake location sheltered from direct wind and rain, away from flues and exhausts, and mount a weather cowl with insect mesh sealed tight to the wall. A short, straight intake sleeve with a slight fall to the outside reduces pressure drop and noise while encouraging any incidental moisture to drain outwards. During commissioning, select the lowest speed that controls moisture reliably, as over-ventilating can create unnecessary air movement. These simple choices deliver discreet, effective background ventilation.

Q) Can the Nuaire Flatmaster be adjusted later if my home layout or moisture load changes?

A) Yes, speed selection on Nuaire Flatmaster can be revisited if your dwelling is extended, internal doors are changed or occupancy patterns shift. A small increase in speed may be appropriate after a kitchen or bathroom refurbishment that alters moisture loads, while a reduction may suit a downsized household. Any adjustment should be accompanied by the usual checks for clear supply paths, open trickle vents and good local extraction. If you add an optional boost switch, you can keep the everyday speed low and use short-term boost when needed. Reconfirm that the external cowl and internal grille are clean so the new setting delivers its intended flow quietly and efficiently. A quick review after seasonal changes can also be helpful in very compact or highly sealed apartments.

Q) What safety and good practice points should I follow when installing the Nuaire Flatmaster?

A) Always confirm the drilling zone is free of hidden services with a detector before coring the wall, and never core near boiler flues or extract terminals. Wear eye protection, a dust mask and gloves, and keep the workspace tidy to reduce trip hazards. Fix the external cowl square and seal it fully to prevent water ingress, and cut the intake sleeve cleanly so the bore remains unobstructed. Provide a suitably rated local isolator, keep mains wiring to electrical standards, and have all electrical work completed and tested by a qualified electrician. Leave clearance around the unit so the front cover can be removed for future filter changes. Finally, label the isolator, note the installation date and speed setting, and show the household how to keep the grille and cowl clean for reliable day-to-day operation.

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