When a flat has no suspended ceilings, it is often assumed that there is no room for heat-recovery ventilation. The real question is broader: where can the unit be installed, the air path routed and safe external connections made without sacrificing essential service access and acoustic comfort? Compromises are possible, but they cannot be chosen from an attractive photograph alone. This article discusses space planning rather than promising one suitable solution for every flat.
First draw the entire air path
A compact heat-recovery unit alone does not remove the need for ducts, external connections and service space. Mark living rooms, wet rooms, existing shafts and possible technical zones on the plan. You can then see which routes are shorter and where finishes would need alteration. Without this layout, buying a unit may simply postpone an unresolved problem until installation day.
The Zehnder ventilation-solutions overview presents equipment types for different building situations. This supports the principle that one type does not cover every home, but it is not a design for a particular flat. At a Lithuanian property, a suitable solution must be coordinated with the structure, communal systems and applicable requirements.
A local ceiling bulkhead instead of lowering the whole ceiling
Sometimes ducts can be concentrated in a corridor or utility area without lowering every room's ceiling. However, heights, door opening and air distribution must be checked. A narrow box in a photograph does not show insulation, connections or fixings. Draw the arrangement with actual dimensions, including everything hidden behind the finish.
The manufacturer's ComfoAir Flex description shows an example of equipment intended for ceiling installation. It cannot automatically be treated as a solution “without suspended ceilings”: this unit also occupies space and requires access. Check specific dimensions, installation position and servicing in the chosen model's documents, not a general advertising image.
Wall-mounted and exposed routes
In some locations, routing part of the ductwork along a wall or leaving it architecturally exposed may work. This can reduce alterations to ceiling finishes but does not suit every living space. Assess appearance, noise, cleaning and whether ducts obstruct furniture. An exposed system should not simply be the consequence of poor concealment options.
Do not specify a smaller duct merely for a neater box. Cross-section, airflow and resistance must be coordinated. An unsuitable compromise may increase noise or prevent the intended airflow being achieved. The final solution must be technically checked, not merely approved against a sample finish.
A decentralised option
Individual room units can reduce the need for a common duct network. However, they require their own external openings, power and coordinated airflow throughout the flat. One appliance in the living room does not automatically prove adequate ventilation in a bedroom or bathroom. If the system works in pairs or alternates direction, assess its operation according to the particular product.
Check noise at the intended operating mode, servicing and outdoor conditions. A declared equipment figure must have its measurement context. It also matters whether open and closed internal doors change the intended result. The solution may be suitable, but it must not be called equivalent to every centralised system without assessing the design.
The façade and communal parts
Before drilling, establish which design, ownership and management approvals are required for the particular building. An external wall, shared shafts and other parts are not merely details of the flat's interior. This article does not set one legal procedure for every building: determine it for the property with the designer, building manager and other responsible parties.
Do not connect a heat-recovery unit arbitrarily to a shared duct of unknown purpose. Its condition, function and permitted use must be known. It is particularly important not to compromise ventilation in other flats or fire safety. A small hole in a wall may have implications for the whole building greater than its dimensions suggest.
Acoustics and neighbours
Equipment sound, duct noise and outdoor sound entering through openings are separate tasks. A quiet fan alone does not resolve them all. In a bedroom, assess normal night-time airflow, not merely the lowest speed in an empty room. Both sufficient airflow and an acceptable sound environment are needed.
Assess external connection locations relative to neighbours' windows and other pollution sources according to the design. A convenient outlet through the nearest wall is not always best. A decorative enclosure must not block a silencer or access needed by the technical arrangement. The owner must understand the compromise before drilling and painting start.
Service space
Plan how filters will be removed, cleaning points accessed and the unit replaced if necessary. An access opening must actually be usable, not merely drawn. If a wardrobe will later stand beneath it, review servicing arrangements in advance. A concealed but unmaintainable system is not an advantage of a professional interior.
Also assess condensate and electrical requirements for the particular product. Not every unit needs the same connections, but necessary ones cannot be forgotten. Do not change the installation position at your discretion merely because it makes the casing easier to fit. The product manual and overall design must agree, not contradict each other.
Checks after installation
Before finally accepting the finishes, check accessible assemblies and intended airflows. Photograph concealed routes so that nobody drills into them later. If part of the design changes during installation, update the layout. The first drawing must not remain the only document when the actual installation differs and the owner can no longer see it.
How should compromises be compared?
In a table, record lost ceiling height, altered finishes, external openings, air distribution, noise and maintenance. A cheaper initial option may mean more exposed ducts, but this is not necessarily bad if consciously chosen. Do not hide limitations behind the word “compact”. Compare every option against the same demand.
In your enquiry, add the flat's plan, heights and photographs; the general principles of airflow selection are explained in the ventilation airflow guide. A solution without continuous suspended ceilings is sometimes possible, but professionalism starts with a drawing of the entire system and clearly accepted compromises, not a promise to hide everything in any flat.
Information sources
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