Categories
Industrial

Hotel Room Acoustics – how noise affects a person’s stay in the hotel

Hotels have been playing an important role during the current pandemic. In certain countries, the local governments have announced that it is compulsory for those entering the country from overseas to carry out hotel quarantine. Taking Malaysia as an example, travellers entering the country regardless from any country are required to undergo hotel quarantine for up to 10 days (as of January 2021), in which the local authorities will arrange the rooms for them unless the travellers opted for Premium Package which of course, costs higher than the standard ones. Travellers will have to take COVID tests in between to ensure that they are COVID-negative and isolating them in the hotels will make sure that there will not be the possibility of spreading the virus to the public since all travellers should be taken as potential risk carrier.

Hotel room comfort

Many may be wondering: How is the cleanliness of the room? Are the meals provided good? What about the Wi-Fi strength there?

But there is one thing that people sometimes forget about: Noise. From the study done by the J.D. Power North American Hotel Guest Satisfaction Survey, it has been consistently shown that complaints on noise issues are significantly under-reported, and hardly being resolved in the end (Simonsen, 2019). Imagine living in a confined space for more than 10 days, where you need to experience constant noise coming from your neighbours, or from outside the room like traffic or construction noise, how will you feel? Looking at some hotel review posts in the Malaysia Quarantine Support Group (MQSG) created to aid travellers coming into Malaysia, there seem to be numerous posts complaining about noise nuisance during their quarantine period. The typical problems faced by members include:

  1. Traffic noise – hotel is located next to busy road
  2. Construction noise in the day from nearby sites
  3. Loud neighbours – speaking loudly especially at sleeping hours

To be exact, these are the similar nuisance one would experience in residential houses.

For short term stays, these may not be the main concern, but it is a totally different case for a quarantine. Unreasonable amount of noise daily for long term, especially after a tired flight and transition at the airport, will lead to unwanted circumstances on a person’s health (physically and mentally).

Noise and Sleep Disturbance

For people who are extremely sensitive to noise, the first thing that can be observed will be that they cannot sleep or even rest well. This will result in sleep deficiency, which slowly drains off the energy to carry out daily tasks. According to Hume, many from the research field claimed that sleep disturbance caused by environmental noise has the most detrimental effect to health. Having an undisturbed night of sleep is even taken to be a fundamental rights and prerequisite to ensure continued health and well-being (Hume, 2010). Hume mentioned that noise pollution can be described as the “modern unseen plague” which may interfere with cognitive processes hence disturbing sleep quality.

To overcome the problem of noise affecting sleep quality, the World Health Organization (WHO – European Office) has brought in experts with relevant documents in recent years to establish the Night Noise Guidelines for Europe. The guidelines contain the latest reviews of noise disturbance and the potential risk to human health. Below are the four ranges of continuous external sound level at night, relating night noise and the populations’ health effects:

<30 dB – no substantial biological effects could normally be expected

30-40 dB – primary effects on sleep start to emerge and adverse effects in vulnerable groups

40-55 dB – sharp increase in adverse health effects while vulnerable groups become severely affected

>55dB – adverse health effects occur frequently with high percentage of the population highly annoyed

These guidelines help to understand the effect of noise on sleep, although a large extent of this topic still relies on fully understanding the fundamentals of the nature of sleep.

Acoustics Solutions for Hotels

As mentioned in the previous sections, the noise complaints for hotel rooms mainly cover traffic noise, noise from neighbours and construction noise. Since sound travels in wave forms, soundproofing will be one of the best concepts to act as a barrier that can effectively stop the sound waves from entering a room from outside.

Typically, there are four methods to achieve the soundproofing effect for hotel rooms (SoundGuard, 2019):

  • Absorption – adding sound insulating materials such as mineral wool or fiberglass for sound absorption, thus preventing sound from passing through
  • Damping – soundwaves often cause vibrations between air particles. Damping helps in reducing or eliminating the vibrational effects by acting as a barrier that does not vibrate
  • Decoupling – In layman terms, this also means separating the walls by adding an insulation layer between the two layers of drywall.
  • Mass – Utilizing thicker, heavier, or denser materials to block sound

While choosing the right material for insulation, it is important to take note on the Sound Transmission Class (STC) rating. The STC rating defines the effectiveness of materials in attenuating airborne sound. The lower the STC rating, the less sound that can be effectively blocked. Therefore, to achieve good insulation results, it is better to use a material with higher STC value.

When should you implement acoustical solutions?

Ideally, it is best to start from the very beginning, which is during the project planning stage (yes, before you even start building it!). Quoting a line said by Scott Rosenberg, the president of Jonathan Nehmer + Associates, and the principal with HVS Design, “You have to think about the inside walls like they’re on the outside” (Fox, 2018). This was said for atrium style hotels which are normally structured like giant echo chambers, where noise from the lobby may travel up to the penthouse suite due to the structure. In the planning stage, allocating which part of the hotel goes where is also crucial to make sure you keep sounds in the right places, and nowhere else. For example, it is important to locate the facilities like gyms, pub, or even spa strategically so that the noise from these places will not affect the guests staying in the hotel rooms. If you really must put them above/below rooms, make sure to use walls or ceilings that are properly insulated.
For existing hotels, another good time to improve the acoustics of the hotel will be during renovation periods. Since you took the step to upgrade your hotel looks and structure, why not consider soundproofing as well? It will definitely help to raise the customers’ satisfaction during their stay.
The areas that can be considered for hotel soundproofing during renovation include:
• Floors – adding soundproofing underlay
• Ceilings – using decoupling methods (dual-layered drywall)
• Doors – changing to solid-core heavy doors with seals
• Walls – adding insulation between walls / use soundproofing paint

 

How do you know if your hotel needs acoustical improvements?

Although some may only start treating the problem after getting significant complaints from customers, hotel owners should consider taking the initiative to find out the noise condition in the building. A good start will be to carry out noise measurement tests to monitor the condition in each room. Having noise data from the measurements will help you understand what the situation is, and how you should resolve them. This is where an acoustics consultant should step in.
It is suggested to consult the acoustics specialists to get the most suitable solution for your case, because not all solutions can be applicable for all conditions. Acoustics consultants can help you to analyse the condition by using methods like indoor noise mapping, material insulation calculations and even tiny suggestions like adding certain types of furniture to aid sound absorption in the room itself.


Effects of Acoustics Improvement to the Hotel

It is proven that by enhancing the acoustics of hotels, business can be improved too. For example, Premier Inn in the UK has pioneered the new design of “floating bedroom” in 2011 at its hotel in Leicester Square. This new design allowed the hotel to resolve the environmental noise and the noise coming up from the nightclub on the ground floor. Premier Inn had also changed their focus from cost to customers’ sleep quality, which enabled them to become one of the best-rated hotels in London (Simonsen, 2019). Thus, the hotels’ business and reputation will strongly improve by taking care of the noise aspects.
Now, back to the starting topic of this article. Hotels are no longer only used as the accommodations for vacations or business trips. Hotels play an important part during this pandemic, being the quarantine centres in many countries. Therefore, it is important to ensure the customers’ (or those under quarantine) comfort during their stay, voluntarily or not. Their reviews make a lot of difference, which will highly impact a hotel’s image to the public. Most importantly, good, soundproofed room means less noise, resulting in better living and sleep quality. Hence, hotel owners are urged to investigate the acoustics aspects of their property, for themselves, and for the customers.


References

Fox, J. T. (2018, July 17). Careful hotel design keeps noise in check. Retrieved February 4, 2021, from Hotel Management: https://www.hotelmanagement.net/design/careful-hotel-design-keeps-noise-check


Hume, K. (2010). Sleep disturbance due to noise: Current issues and future research. Noise Health, 12(47), 70-76. Retrieved February 2, 2021, from https://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2010;volume=12;issue=47;spage=70;epage=76;aulast=Hume


Simonsen, J. (2019, June 20). Why and how to reduce noise in hotel rooms. Retrieved February 3, 2021, from Rockwool: https://www.rockwool.com/group/advice-and-inspiration/blog/why-and-how-to-reduce-noise-in-hotel-rooms/


SoundGuard. (2019). Hotel Sound Reduction – How to Soundproof a Hotel Room. Retrieved February 3, 2021, from SoundGuard: https://soundguard.io/hotel-sound-reduction-soundproof-hotel-room/

Categories
Environment Industrial Noise and Vibration Product News

Noise Monitoring for your home, Thailand

 

The first DIY noise monitoring, easy to use and install, just plug in the power, wifi and ready to go, online data noise monitoring, accurate, calibrated, weatherproof. Automated alarms by email or messenger.

Noisy neighbours, noise from entertainment or from a factory, road noise?

Register the noise and discuss with the authorities how to resolve the issue.

SpotNoise noise monitoring from the Netherlands, now available via Geonoise Thailand for South East Asia.


Noise Nuisance Monitoring Thailand Noise Nuisance Monitoring Thailand, Malaysia, Indonesia, Vietnam

 
 
Categories
Asia Noise News Building Accoustics Environment Industrial

Noise Level Prediction in Industry (Oil & Gas, Power Generation, Process, etc.)

Most industrial activities create noise that can be harmful to the environment as well as to their workers. To minimize this effect, governments, associations, and companies have created regulations, standards, and codes to set the allowable noise both inside the sites, that can be harmful to the workers, as well as to the environment. In a lot of cases, during the planning phase, the plant owner and project management want to be sure that the noise levels are acceptable. Since the plant is not built yet, what can be done is creating a noise model to simulate the plant, so that the noise levels can be predicted. In this article, we will explore how we can do so.

The first thing we must know is how much noise does the noise sources inside of the plant will emit. The noise source is usually described in two ways which is Sound Power Level (Lw or SWL), and Sound Pressure Level (Lp or SPL) in certain distance, most commonly Lp in 1 m distance. There are multiple ways to get this information for certain noise sources. First, if the equipment type and model have been chosen, the equipment manufacturer will normally report the noise level in their datasheet. However, this is not usually the case with most of noise predictions since the noise study is normally done before the equipment suppliers are appointed. So, the second way to be able to predict the noise emission is by following empirical formulas that are developed by researchers. You can find such formulas in some textbooks, journals, and papers. For rotating parts, you will need its rated power and rotational speed to be able to estimate the noise emission. 

For example, in the speed range of 3000-3600 rpm, the noise level of a pump with drive motor power above 75 kW can be predicted using the following equation:

Suppose a pump with rotational speed of 3000 rpm and 100 kW, according to the formula, it can be estimated that the noise level at 1 m from the pump would be 92 dB. And suppose the noise source can be considered as point source on the ground (hemisphere propagation), the sound power level of the pump can be calculated using the following formula:

Where r is the distance from source to receiver

And in this case, the predicted Lw would be 100 dB.

Thirds, noise measurement to a similar equipment can also be an option to be able to determine the noise level of the new equipment. Another option, in some countries, there are noise emission limit for certain equipment, you can use that limit if it is applicable for your project.

After the Lw of all noise sources is obtained, we want to calculate the noise levels (the Lp) at the receivers. There are some standards which procedure can be followed to calculate this. Few of which are ISO 9613-2, NORD 2000, CNOSSOS EU, and many others. Most of the standards consider some factors to the calculation such as distance, atmospheric absorption, ground reflection, screening effect (from barriers and obstacles) and other factors such as volume absorption from vegetation, industrial site, etc. Most consultants and projects will require a software such as SoundPLAN to do this calculation.

Depending the project, there are few types of noise limit which compliance will need to be ensured. The most common ones are environmental noise limit, noise exposure limit, area noise limit and absolute noise limit. Besides, the noise level during emergency is also modelled so that the information can be used for safety and PAGA (Public Address and General Alarm) study.

Environmental noise limit is usually calculated for the plant’s contribution to the plant’s boundary as well as to the nearest sensitive receiver such as residential and school near the plant. How this is accessed depends on the regulation applicable on the plant area. In Indonesia for example, the noise limit for residential area is Lsm 55 dBA and industrial area is Lsm 70 dBA. Lsm is a measure like Ldn, but the night noise level addition is 5 dB instead of the 10 dB addition that most other countries, especially Europeans use. To ensure compliance with this regulation, the noise level at fence should be less than Lsm 70 dBA, and suppose there is a residential area nearby, the contribution from the site should be less than 55 dBA. It is also advisable to measure the existing noise level at the sensitive receivers to make the study more relevant to the situation. 

Noise exposure limit is the maximum exposure to noise that the workers get during their working period. In Indonesia, the noise exposure limit is 85 dBA for 8 working hours. To change the working hours, 3 dB exchange rate is used. For example, if the noise level in the plant is 88 dBA, then the workers can only work there for 4 hours, if it is 91 dBA, then the time limit is 2 hours, and so on. To extend the working hours on a noisy area, the options are to actually reduce the noise level by reducing the noise emission from the source or noise control at transmission (for example using barrier), or by usage of Hearing Protection Device (HPD) for the workers such as ear plugs and ear muffs. The noise exposure of workers after usage of HPD can be calculated using the following formula:

Where NRR is the noise reduction rating of the HPD in dB.

Different area might have different noise level limits, and therefore area noise limits are useful. For example, in an unmanned mechanical room, the noise level can be high, for instance 110 dBA. However, inside of the site office, the allowable noise level is much lower, for example 50 dBA. This noise level shall be calculated to ensure compliance with the noise limit. Different companies might have different limits for this to ensure their employees’ health and productivity. If the area is indoor and the noise source is outdoor, then the interior noise level can be estimated using standards such as ISO 12354-3. 

The absolute noise limit is the highest noise level allowable at the plant, and shall not be exceeded at any times, including emergency. In most cases, the absolute noise limit for impulsive sound is 140 dBA. To ensure compliance with this requirement, potential high-level noise shall be calculated, for example safety valves.

During emergency, different noise sources than normal situation will be activated, such as flare, blowdown valves, fire pumps, and other equipment. In such cases, the sound from the alarm and Public Address system must be able to be heard by the workers inside of the plant. Normally the target for the SPL from the PAGA system should be higher than 10 dB above the noise level. Therefore, the noise level during emergency in each area should be well-known.