hi yes it will reduce thermal efficiency as heat escape more through glass and a panel normally is insulated between the layers. but u can change from panel to glass what u will need to do is remove the beads around the panel. for this u will require a scraper. i will post a link check it out. then once the beading is removed u will need to measure the panel length and width. also u will need to measure the thickness and take these to a glass dealer. a door requires the glass to be toughened so its not a danger if it ever breaks.
http://www.youtube.com/watch?v=9dV862oDMgc
kash, February 2013
