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Why should you care about humidity levels of your hotel?

This is the fourth article from our “25’000 – every breath counts – Importance of Indoor Air Quality Monitoring in Hotels” – ARVE series.

Do you know the feeling of waking up in a hotel room, with a scratchy throat or dry eyes? Or on the contrary, have you ever entered a hotel room that had a musty odor that you could not explain? If you did, you are not alone. 50% of all negative hotel reviews are related to the room climate [5]. So, preventing them in the future would increase the popularity of a hotel substantially. Well, we are telling you that you can (or at least many of them). Because most of those situations might be related to the humidity levels in the hotel.

“Humidity is the amount of water vapor in the air. Relative humidity refers to the amount of water in the air compared to the total amount it could contain at a specific temperature [2].”

The ideal level of relative humidity (%RH) is between 40% and 60%. This is when we talk about a comfortable indoor climate.

Humidity levels can have a destructive effect on guest experience and satisfaction. Even worse, from a hotel operator’s point of view, it can generate high costs, that could be prevented, when humidity is handled properly [2].

Depending on the season, the geographical location, and the heating & ventilation system, hotels can experience two kinds of challenges: too low or too high humidity levels [4]. Both can have negative effects on the hotel operations.

High Humidity

Excessive moisture in hotel rooms affects hotel structure, staff well-being, and guest experience.

Hotel Structure

  • Mildew and mold infestation: after a certain period of high humidity levels in hotel rooms, the risk of mold infestation increases dramatically, which in turn causes substantial damage to the interior of the hotel, resulting in an increase of renovation costs of up to 20% [4]. This is an especially great risk for hotels with many idle rooms.

  • Condensation may form around the bathroom, on windows, and on walls. This and other factors can increase the time spent on room cleaning [4].

  • Moisture in wooden furniture can not only shorten its lifespan but excess humidity leaves it with a musty odor.

  • Dirty-looking walls: the temperature difference between the outdoors and the indoors can cause “sweating walls” [2].

Staff Well-Being and Guest Experience

  • Mold can cause that some guests and staff might experience everything from mild allergic reactions to nasal congestion, cough, irritation of the throat, eye, and skin, or even asthma attacks [4].

  • A musty and stuffy smell in the room leads to lower guest satisfaction [4].

  • Reduced sleep quality, due to uncomfortable conditions [4].

Low Humidity

Especially, during the cold winter months, relative humidity is often below 30%. Such low levels of humidity can affect your staffs’ and guests’ well-being and cause discomfort such as dry and itchy skin, dry lips, frizzy hair etc. Furthermore, without humidification, the danger of airborne transmission of illnesses such as SARS-CoV-2 increases significantly. That is because aerosols that contain viruses are staying in the air for longer in dry environments. Furthermore, low humidity can lead to a dry nose, throat, and skin, which reduces the natural resistance of our bodies [1].

Additionally, to a reduced guest experience, dry environments can also affect your hotel structurally. Dry air can pull the moisture from wooden materials, which leads to problems like doors that are hard to open or close, creaking floors, or wood furniture that starts to bend or even crack at some point [3].

Both, high and low humidity can increase the need for renovation of your hotel and evoke negative guest reviews. So, being able to identify problem areas and implement preventative measures can lead to substantial cost savings.

What can you do?

So now you know why you should care about humidity levels. But what can you do about it?

Step 1: Monitoring

Before you invest in any expensive machinery to act on the humidity, first start monitoring the air quality and with it, the humidity levels. Observe it during a period: Are there some rooms that are drier than others? Are there rooms that are always humid, even though the weather is cold outside? Is there a specific room type that is prone to humidity problems?

Step 2: Analyze and Learn

Next, find reasons, why the humidity problems persists and if it comes from internal or external sources.

Internal: Are the windows in the affected room properly insulated? Is there a water leakage? Does your HVAC and ventilation system work the way it should? Is there moist air coming from the kitchen or laundry areas of your hotel?

External: Does your HVAC system properly regulate the temperature difference outdoors vs. indoors?

Step 3: Take actions

Only when you have monitored your humidity levels and know which rooms are prone to dry or moist air, you can decide what actions make sense, operationally and financially. You take preventive measures, such as dehumidifying the air before mold has a chance to form [4]. Or you add humidifiers to the rooms / hotel floors that are prone to dry air, to avoid bad guest reviews of guests feeling unwell in the room environments.

Step 4: Keep monitoring

Keep monitoring the humidity and temperature levels to measure the impact of your actions on the comfort zone of the rooms and the guest experience.

Step 5: Harvest the rewards

By doing all the steps above, you will be able to profit from higher staff productivity, improved guest reviews, and optimized maintenance and renovation costs in the longer term.

About ARVE Swiss Air Quality System

ARVE monitors the indoor air quality in real-time and generates actionable insights for hotels making use of Artificial Intelligence and Machine Learning. The ARVE Swiss Air Quality System not only monitors the air quality including humidity in real-time but also provides you with an overview of your entire building. With the ARVE actionable insights on critical situations like mold conditions, you can cross-reference the situation with historical data and take actions when needed. Go to to book a demo today.

#hospitality #arveswiss #humidity #airquality #airqualitymonitoring #renovation #hotel #CSR #guestsatisfaction


1. SECO. (August, 2020). Wegleitung zur Verordnung 3 zum Arbeitsgesetz. Raumklima. Page 316-1 – 316-13.

2. Condairgroup. (2020). Humidification in Hotels and Wellness Areas.

3. BPI. (August, 2018). Cause and Effect: Leaky Homes and Out of Whack Humidity Levels.

4. Peart, M.V. (n.d.). Introduction to Hotel Mold / Moisture Problems in Warm Climates.

5. HotelTechReport. (August, 2020). What is Preventive Maintenance? Definition, Examples & Tech Tips.

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