19/10/2025
What does relative humidity actually mean in an occupied home????
Let’s ask AI…
Relative humidity (RH) in an occupied home refers to how much moisture is in the air compared to the maximum amount the air can hold at a given temperature. It’s expressed as a percentage. For example, 50% RH means the air is holding half the moisture it could hold before becoming saturated.
Here’s what it means for your home and comfort:
1. Comfort
• Ideal range: 30–50% RH is generally considered comfortable for most people.
• Too low (60%): Air feels muggy, and you may feel warmer than the actual temperature.
2. Health
• Low RH: Can dry out nasal passages, increasing susceptibility to colds and respiratory issues.
• High RH: Promotes mold, dust mites, and allergens, which can trigger asthma or allergies.
3. Building & Furnishings
• Low RH: Wood floors and furniture can crack or warp.
• High RH: Moisture can damage walls, paint, and cause condensation on windows.
4. Energy Efficiency
• Higher humidity makes air feel warmer, so you might lower heating in winter—but in summer, high RH makes cooling harder, increasing AC costs.
There are many ways to lower humidity levels, some cost £££ some don’t.
Things that cost money but are proven to work are
✅ Extractor fans
✅ Dehumidifiers
✅ Passive ventilation units
✅ Passyfer vents
Things that don’t cost money but do take some of your time and efforts are..
✅ Passive ventilation- opening windows and doors.
✅ Limiting drying washing indoors when possible.
✅ Limiting moisture production where possible.
There are other factors such as adequately heating the space, not over crowding etc.
Fighting condensation is multi faceted. It’s not always easy and can be distressing!
If your needing a hand or some advice please get in touch 🤝
We are here to help ❤️
www.tdgdamp.com
