Commercial Refrigeration, Noise & Decibels

Working in a commercial kitchen is noisy; there's no getting away from the raised decibels of busy, energetic staff, but commercial-grade refrigeration equipment will also add to the commotion. Commercial fridges, freezers and cold rooms are louder than domestic models, but why is this?

We understand that catering refrigeration can be a significant investment and making the right choice is vital. Read on for information about the regulations surrounding noise pollution from commercial refrigeration, what type of commercial fridges and freezers are available, and why they can be louder than domestic models. By understanding the basics you can design your commercial kitchen for optimum efficiency while making it a pleasant workplace that doesn't leave your ears ringing by the end of service.

Most refrigeration, both domestic and commercial, uses a compressor system which sucks in warm air, cools, and expels it from the back or side. Without getting too technical, compression works by vaporising a liquid called a refrigerant and moving it through coils or tubes when air from the refrigerator compartment is blown through the loops ("box air"). You'll probably recognise the low buzzing sound from your kitchen. The compressor motor, which pumps the vaporised liquid through the coils, makes that noise. There may also be a very small amount of sound from the fan's movement. Systems are larger and more powerful in commercial equipment hence will be louder than domestic appliances.

The exception to the commercial refrigeration rule can be seen with hotel room fridges or minibars, known as absorption fridges. These use a different cooling method involving ammonia, water and hydrogen. This process is much quieter but requires more energy than a compressor system. The 'silent' operation makes these mini fridges perfect for areas where ambient noise is lower such as hotel rooms and boardrooms etc.

Some smaller chillers operate with a thermoelectric system and may therefore be referred to as thermoelectric fridges. These refrigerators employ a pump to move heat from one side to the other instead of a compressor, resulting in a warm side and a cold side, with a temperature variation between the two areas of around 20°C. Additionally, because there is no liquid involved in the cooling process, there is no bubbling sound; instead, there is only the background hum of the fan at the back of the refrigerator which cools the ambient temperature to make the fridge work more effectively.

Another commercial option is remote refrigeration. As the actual working part of the refrigeration system (and the bit that makes the noise) is situated away from where food is stored or displayed, noise levels can be reduced in commercial kitchens and on public shop floor areas.

In a commercial environment, it's worth considering remote systems and noise pollution. The part of the refrigeration system that sits on the exterior of the building will generate noise throughout its operation, and the noise you can hear inside your premises. Additional noise means you must consider the positioning of the unit on the exterior wall when planning an installation and any regulations regarding distance from neighbouring buildings, especially in residential areas.

Commercial refrigeration is usually louder than domestic refrigeration due to the type of compressor systems used. Commercial grade compressors require more power than domestic refrigerators, resulting in louder noise levels. These powerful compressors ensure that commercial refrigeration is capable of constantly running to keep food chilled or frozen, even when doors are frequently opened and closed. A compressor system makes them more energy-efficient than absorption refrigerators but also louder.

While increased noise levels aren't necessarily a problem in busy kitchens, shops or bar settings where ambient noise is often louder, it may cause issues in other environments - predominantly domestic.

Domestic refrigeration will only undergo occassional use, such as getting the milk out for a cuppa, and therefore components don't have to work as hard to maintain the correct temperature. This will result in quieter operation as the refrigeration doesn't undergo excessive stress or pressure to perform. Commercial refrigeration has to work so much harder, not only due to the size of the equipment and the increased content capacity but also with doors being frequently opened and for longer periods while produce is retrieved during busy services. Components have to work harder to maintain fridge or freezer temperatures and therefore will generate more noise.

People often want to buy commercial bottle coolers and commercial wine coolers for home, thinking that the product will be better quality…yes it is, but it also comes with the noise of a commercial piece of refrigeration. The increased operational noise of commercial refrigeration will be noticeable.

Increased noise may also cause issues in quieter areas such as meeting rooms and offices. Noise level and volume can be influenced by the size of the room, the decor, also the types of walls. For instance, many modern builds don't have brick built walls, only insulated plasterboard room divides.

The type of flooring in domestic or quieter business properties is also a consideration; carpet is noise insulating, whereas wooden floors can reverberate noise. Furniture positioning makes a difference as a minimalist room can quickly reflect and absorb more sound, causing echoes and reverberations, further increasing the noise level. More noise becomes incompatible with areas designed initially for quiet working over time.
  

Anyone who has worked in hospitality or catering will know the increased noise that comes with industrial-grade refrigeration equipment. Manufacturers design industrial components to work harder, be more robust and produce more powerful results. As a result, the noise levels can be much higher than regular domestic fridges.

The government sets out the UK regulations surrounding noise pollution for commercial refrigeration in EN ISO 3744:2010 – Acoustics. EN ISO 3744:2010 lays out the measurement of sound insulation in buildings and associated elements. It also defines an engineering method for creating equipment which emits noise at a sufficiently low level so that it is at acceptable levels over an area without obstructions and reflective surfaces (a free field).

The standard limits the sound emitted from commercial refrigeration equipment and tests at various frequencies between 125 Hz and 4 kHz (cycles per second). In addition, many manufacturers will go above and beyond these standards during testing to ensure their products have the best possible performance when reducing noise pollution.

The decibels that commercial refrigeration generate may typically range between 45dB – 75dB as opposed to domestic levels of roughly 32dB – 47dB depending on the unit. This commercial reading, however, is only a general guide; the decibels may increase or decrease depending on the type, function and size of equipment.

It's worth pointing out that noise pollution testing is based on use in commercial premises and associated environments and not domestic situations.

Decibels (dB) measure sound pressure level, a logarithmic scale that describes the loudness or intensity of sound and other noise sources. Every sound is measured in a range of decibels, from 0 dB (the threshold of human hearing) to 130 dB (the loudest sound humans can tolerate without pain).

Decibels matter because they determine how comfortable the environment is for customers and staff in a typical public setting with the usual activity, conversations, a bit of background music, and general chatter. Commercial refrigeration noise will not be that noticeable in these social or working conditions such as busy catering kitchens, a shop floor or a pub or bar.

Commercial refrigeration will be significantly more noticeable in quiet meeting areas, for example, or in a domestic setting. Nothing is more annoying than the constant buzz of an appliance when you're trying to concentrate.

Below is how we interpret what decibels sound like...

The average commercial refrigerator operates between 45 dB and 75 decibels; most domestic fridges range from 32db to 47dB. The louder the refrigerator, the more disruptive it may be in a shared workplace or if it's in a quiet residential area.

While the majority of the sound is just a natural by-product of the compressor and fans working to chill your unit, there are things that you can check which may be causing excessive noise.

Things to consider - is your refrigerator levelled correctly? Also, it's worth checking for loose fittings, such as shelves, internal loose fittings, doors, or handles.

Consider investing in soundproofing panels, if appropriate, which can significantly reduce noise levels. Panels can minimise sound leakage while allowing ventilation, so the unit does not overheat – this should reduce the decibel level to below 50 dB.

If you notice an increase in noise levels beyond your expectations, it's worth checking to ensure the refrigeration system functions correctly and that expected temperatures are being achieved. As a best practice, regularly clean, check and maintain your commercial fridges. If there is any sign of problems or potential faults, call an engineer and get it checked out.