I woke up to find all of my windows covered in condensation.
Why it matters: Condensation can damage building materials.
- Knowing when it will occur can inform how we manage the issue.
🤓 Nerd alert!
- The good news is I won’t make you do any math.
🖼️ The big picture: Water condenses on a surfaces when that surface is at or below the dew point.
- The dew point is a temperature that changes based on two factors.
👉 Air temperature
👉 Relative humidity
🙋♂️ Your weather app will tell you the current dew point.
🧮 By the numbers: Let’s use my house and the current conditions to unpack this.
- When I woke up the outdoor temperature was 73 degrees and the relative humidity was 95% — yuck!
- That makes the dew point 71 degrees.
- My indoor temperature was 69 degrees.
🧐 So what happened?
- With the outdoor temp so close to the dew point and my indoor temp below the dew point
- The glass on the outer pane (my windows are double-paned) got to 71 degrees (or colder) and condensation formed.
- With the high humidity in the air and the sun not yet shining on the windows
- They can’t dry yet.
✅ For your Smart Homeowner list
😁 If you’re still with me, here are two takeaways.
- Understand the dew point. Start checking the dew point on your weather app on humid days.
- Paint your house—especially your siding—if it’s been more than 10 years since you last painted (or less depending on paint quality). Paint protects materials from moisture.