Maybe OP means the rod is placed in the windows. I've done that.
I have day/night shades with valance on top on all my windows.
I took an expandable shower rod and put it "under" the top valance so you don't see it and I too bought room darkening drapes to hang on it.
1. At night no one can see in. They can with day/night shades. Yup I was surprised about that also.
2. It does keep the heat out from the hot sun in summer.
3. Keeps the cold out in winter time.
4. Makes a big difference on how efficient your ac and/or furnace will work.
4. you just push the drapes to the sides when not in use.
We must be willing to get rid of the life we've planned,
so as to have the life that is waiting for us.