Acoustic panels for ceilings are one of the most effective ways to improve the acoustics in a room, because the ceiling is the largest uninterrupted surface and often the one that reflects the most sound. However, the panels are available in many materials, formats and qualities, and the right choice depends on more than price and appearance. In this guide, we review the four factors that actually determine whether your acoustic panels will work as expected, and how to find the solution that suits your particular room.
When are acoustic ceiling panels the right solution?
Acoustic ceiling panels make the most sense in rooms where sound builds up and turns into reverberation and background noise. This typically applies to rooms with large surfaces of glass, plasterboard, concrete or laminate, where the sound has nothing to grip onto. In practice, the problem can be recognised by difficulty holding conversations, unconsciously raising your voice, or becoming tired more quickly in the room.
The ceiling is usually the first place to look for a solution. It is typically the largest uninterrupted surface in a room, and because it is rarely used for furniture, shelves or pictures, there is both space and practical sense in letting the acoustics work from there. Wall panels and soft furnishings can supplement, but the ceiling alone can often improve the room significantly.
If you are completely new to the subject, it may be a good idea to first read our article about what an acoustic ceiling is, and how it works, so that you understand the basic concepts before you start comparing solutions.
The four factors that actually determine the choice
When looking at acoustic ceiling panels, it is easy to become overwhelmed by technical data sheets and product descriptions that promise a lot. In practice, the choice comes down to four factors, and once you understand them, the rest is often details.
The first is the material, because it determines the acoustic performance, weight, installation method and indoor climate. The second is the acoustic effect, meaning how much sound the panels actually absorb, and how many m² are needed to make a noticeable difference. The third is installation, which is often the factor people underestimate the most. And the fourth is aesthetics, which concerns how much the panels may influence the room's overall appearance.
We review all four in detail in the following sections, so you have a basis on which to make your decision.
Choice of material and what the panels are made of
The material is the most important individual choice, because it affects almost everything else. On the Danish market, there are typically four categories to choose from, each with its own characteristics.
PET felt is a modern material made from recycled plastic, often from plastic bottles. It is lightweight, flexible, fire-resistant and emits very low levels of VOCs. Arku's panels, for example, are made from 60% recycled PET and 40% thermoplastic binder and weigh around 2 kg per m². The low weight means that the panels can be glued directly in place without screws or visible fittings. The material is also colourfast and requires no maintenance.
Mineral wool is the classic industrial material and is typically found in the form of suspended ceiling tiles in office buildings. It has good acoustic performance and is widely used in commercial projects where a suspended rail system is part of the overall ceiling construction.
Plasterboard with acoustic perforation is another option, where an ordinary plasterboard panel has holes or grooves that absorb sound. It provides a smooth, monolithic appearance and is often included in larger construction projects where the ceiling is built from scratch.
Wood and slatted ceilings provide a natural appearance and can be very attractive. The acoustic effect depends on what is behind the slats, and an underlying absorbent material is usually necessary for the slatted ceiling to function acoustically.
Wood wool cement is an established material for acoustic ceilings that provides a raw, industrial appearance. It consists of wood wool and cement and is widely used in commercial buildings and institutions. The material has good acoustic performance, and the choice between wood wool cement and other materials typically depends on the project's aesthetic and practical priorities.
If you are looking for a lightweight solution that is maintenance-free and easy to install yourself, Arku's PET felt acoustic panels are an obvious choice, and you can see the full range in our collection.
Acoustic effect with NRC, class and air gap
When comparing acoustic ceiling panels, you will come across the term NRC, which stands for Noise Reduction Coefficient. It is a number between 0 and 1 that indicates how much sound the panel absorbs on average. A panel with an NRC of 0,90 therefore absorbs 90% of the sound that hits it, while the rest is reflected.
Acoustic panels are classified in absorption classes from A to E, with A being the best. A class A panel has an NRC above 0,90, class B is 0,80-0,89, class C is 0,60-0,79, and class D is 0,30-0,59. For private homes and ordinary offices, class C or better is usually sufficient, while rooms with special acoustic requirements, such as restaurants or meeting rooms, should often have class A.
It is important to understand that the same panel can have very different NRC values depending on how it is installed. Arku's panels are a good example. Installed directly on concrete or plasterboard, they achieve an NRC of 0,40 and fall into class D. With an air gap of 100 mm behind them, absorption increases to NRC 0,70 and class C. With a 200 mm air gap, absorption increases further to NRC 0,85 and class A, which is the highest absorption class.
The explanation is that sound at lower frequencies has longer wavelengths and therefore needs more space to move before it can be absorbed effectively. A panel installed directly on a hard surface can only capture the higher frequencies, while a panel with air behind it also captures the bass range. This is one of the reasons why the same product can perform very differently in different rooms.
How many m² you need depends on the size of the room, the purpose and the class you are aiming for. As a rule of thumb, covering 30-50% of the ceiling surface makes a noticeable difference in most private rooms. We return to the specific calculation further down.
Installation on an existing ceiling or new construction
Many people underestimate how significant a factor installation is. It is often here that a project either becomes simple or complicated, and it is worth clarifying before choosing a material.
Arku's panels can be glued directly onto concrete, plasterboard or existing ceiling tiles, because the material weighs only around 2 kg per m². Ordinary construction adhesive is enough to hold them up without screws or fittings, and the process is quick enough for one person to complete an ordinary room in an afternoon. We have written a separate guide on installation on an existing ceiling, which explains which ceiling types are suitable and what you should check before getting started.
Arku's PET felt panels are stable in both humidity and temperature fluctuations and can therefore be installed as soon as they are unpacked, without prior acclimatisation in the room. This makes the process more flexible and allows installation to be planned according to the project's pace rather than the material's.
If you are installing on a completely new construction, you have several options. Direct installation provides the most discreet appearance and is the quickest. A suspended construction provides better acoustics due to the air gap, but requires more planning and typically costs more ceiling height. The choice depends on how good the acoustics need to be and how high the ceiling already is.
Aesthetics and the room's appearance
Acoustic ceiling panels must also fit visually into the room, and this is where many decisions are actually made. There is a big difference in how visible the panels are and how much they affect the room's overall appearance.
Colour is the first choice. White or light panels blend into an ordinary ceiling and become almost invisible, which is an advantage if you want to maintain a minimalist look. Dark panels create contrast and become a design element in themselves, which may be desirable in, for example, an office, a café or a special room where the ceiling should be part of the style.
Format and placement also matter greatly. Large, continuous surfaces provide a calm appearance, while smaller panels arranged in a pattern create more visual dynamism. Some choose to cover the entire ceiling, while others create a defined zone above, for example, the dining table or sofa area, so the acoustics only work where people primarily spend time.
If you are unsure what a solution will look like in a finished room, it can help to see specific examples. We have collected a number of projects on our inspiration page, where you can see how acoustic panels have been used in different room types and styles.
There is also a case study from a private home in Stevnstrup, where you can follow through the home and see how Arku is installed in several rooms. This provides a good impression of how the solution works in an ordinary Danish home and what it does for both appearance and sound.
Indoor climate, fire and sustainability
Acoustic panels are installed on the ceiling around the clock and cover a large surface area in the room. Therefore, it is relevant to know what they are made of and how they affect the indoor climate. This is particularly important in homes with children, in bedrooms or children's rooms, and in spaces where people spend long periods of time.
Fire class is the first thing you should check. In private homes, the requirement is typically class D or better, but public buildings and commercial premises often require class B-s1,d0, which is the second-highest classification under EN 13501-1. Arku's panels are tested and classified as B-s1,d0, which means high fire resistance, very limited smoke development and no burning droplets. This makes them suitable for all types of rooms, including places with stricter safety requirements.
VOC emissions, meaning the release of volatile organic compounds, are another important factor. Many older or cheaper materials emit substances that can affect air quality and cause symptoms such as headaches, irritation of the eyes and respiratory tract, and in rare cases more serious reactions. Arku's panels are tested according to EN 16516, and the results show emissions below 0,067 mg/m³, which is far below the European limit values for building materials. This means that the panels do not emit odours or unhealthy fumes, and that they can be installed in bedrooms and children's rooms without concern.
Sustainability is a factor that many people value increasingly highly. Arku's panels consist of 60% recycled PET, including plastic bottles from the oceans, and the product can be recycled at the end of its life. The panels also have an environmental product declaration (EPD Danmark MD-25187-DA), which documents the product's environmental impacts per m².
How to calculate your needs in m²
Once you have chosen the material and decided on the aesthetics, it is time to determine how many m² of panels you need. As a rule of thumb, covering 30-50% of the ceiling surface provides a noticeable improvement in most private rooms, while 50-70% provides a significant effect, which is often the goal in offices and cafés.
A calculation example can make it more concrete. In an ordinary living room of 25 m², where you experience a little too much reverberation and background noise, around 8-10 m² of acoustic panels will typically provide a noticeable effect. This corresponds to an area of approximately 3 x 3 metres above, for example, the sofa area or dining table. If the acoustics are very harsh, or if the room is used as a home office, it may be a good idea to increase this to 12-14 m².
Once you have the figure, it is worth considering the actual size of the panels so that you can plan the layout and minimise waste. Arku's panels are available in two formats, one larger and one smaller rectangle, so you can adapt the layout to both small and large rooms. You can see sizes and prices directly in our collection, where you can also choose a colour and order a sample kit if you want to feel the material before deciding.
For larger rooms or projects with high ceilings or special acoustic requirements, the calculation can become more complex, and in these cases it makes sense to ask for help.
When should you speak to an adviser?
Most private projects can be handled based on the guidelines we have reviewed here. However, in some cases it pays to have a brief conversation with someone experienced in acoustics before ordering materials.
This typically applies if the room is over 40 m², if the ceiling height is over 3 metres, if the room has sloping ceilings or a vaulted ceiling or open-plan layouts, or if it is to be used for purposes with stricter acoustic requirements, such as music practice, podcast recording or meetings with many people. It also applies if you have made previous attempts that did not work as expected, because there is often a reason that needs to be identified before choosing the next solution.
Arku is happy to advise on material selection, quantities and installation if you send an enquiry with photos and measurements of the room. It is always non-binding, and it provides a better starting point than guessing.
