The A/C unit in my house is really old and doesn't work well. Works OK for downstairs, but upstairs get basically nothing. I would like to just get window units for upstairs and completely close off the rectangular ducts leading upstairs. It seems like I would need some type of damper to put into the ducts.
Does anyone know a simple, inexpensive way to do this? I'm pretty handy, so I could probably do it myself. Just wanted to know if anyone has any experience.