I definitely think this is a great idea :)
I have a personal altar that sits right up against a window, and I open the window as soon as the sun is up, and close the window when the sun goes down- I like the sun to touch my altar, to warm the wood, and to cleanse it. (I wouldn't open the window depending on the atmosphere, the type of wood or material the altar is made from, the moisture in the air, etc)
I also think, depending on what you use the altar for, it can have benefits. When I do work with fire, I like the sun to be directly involved. To each their own- but it's a yes from me.