Why guest rooms smell musty in colder months and what you can do about it

When colder, wetter weather arrives, many hotels experience a rise in musty or damp smells in guest rooms. These odours are more than unpleasant. They influence perceptions of cleanliness, reduce guest satisfaction and can lead to complaints or refunds.

What causes musty smells in guest rooms?

1. Increased humidity and condensation

During autumn and winter, moisture builds up from wet coats, damp shoes, bathroom steam and reduced ventilation. In sealed rooms, this humidity has nowhere to go and can promote mould growth.

2. Reduced airflow

To conserve heat, guests and staff are less likely to open windows. This limits fresh air exchange and traps odours, airborne microbes and mould spores.

3. HVAC issues and shared air systems

Heating and ventilation systems can recirculate stale air or draw odours from other rooms, especially if filters are not maintained. Poor circulation also encourages mould to thrive in corners and behind furniture.

4. Absorption into soft furnishings

Curtains, carpets and bedding absorb moisture and odours, including mould-related compounds, releasing them slowly back into the air.

Why it matters for hospitality
Musty smells are one of the most common causes of guest dissatisfaction during colder months. They are often associated with mould, poor hygiene or lack of maintenance, even if the room appears clean. Mould spores can also trigger respiratory symptoms in sensitive individuals. A single comment about room odour in an online review can significantly reduce future bookings.

What hotels can do
• Ensure HVAC systems are well maintained and filters replaced regularly
• Encourage staff to report persistent smells, damp patches or signs of mould quickly
• Use dehumidifiers or moisture absorbers where humidity is a known problem
• Deploy AIRsteril MP100 units between guests to restore fresh air
• Install continuous AIRsteril units in problem zones to prevent recurrence

Why AIRsteril is effective
Unlike sprays or filters, AIRsteril removes odour molecules and reduces microbial activity, including mould. That means:
• Faster room turnaround after complaints or heavy use
• Prevents recurring odour issues in problem rooms
• Better guest satisfaction and protection of your brand

Speak to our team about improving winter air quality and guest satisfaction in your hotel.