I have a couple windows on the SW side that get blasted by late day summer sun.They are thermopane but you can still feel the heat coming thru them. I covered one on the outside with plywood and that worked good. The other one is visible so I dont want to cover it outside. I put drapes on the inside but once the rays hit the glass there is still some heat that gets thru. Is there a good block I can put on the inside that will send the rays out again or is heat build up inevitable to some degree..??