Home DIY

Indoor humidity will be lower than outdoor due to warmer temps (about 15% lower in my experience). Here's the plot of a couple of humidity sensors from my flat:

• The outer hall is an unheated hallway that we share with the flat upstairs. It's not well sealed and is a good 5 deg C colder than inside our flat
  
• The inner hall is pretty representative of our flat. The spikes correlate to (nearby) bathroom use
  

1 Attachment