My wife and I have had an ongoing argument about various cleaning agents, and I wanted to get a Chemists' view on it.
When we are doing laundry, she will generally clean using the cold water setting and a standard amount of detergent.
If I do laundry, I will use the warm water setting with a standard amount of detergent.
Either way, the clothes come out (seemingly) clean. Using cold water saves energy from the heating process, which has been her excuse for doing such a dastardly thing. Her argument against using warm water is that it will damage/shrink the cotton. While I don't disagree on that point, I am curious if the use of warm water causes the detergent to work better or not.
In addition, there are various soaps that work best in cold water.
What is the actual mechanism at work here? Why do some soaps work better in cold (or hot) temperatures?
To make things a bit better, let's remove some more variables. We use this detergent:
Unfortunately I can't find information on the normal temperatures those machines operate at.
Also who is right? (I bet it's her)