Bubble wrap window insulation testing
I have a large amount of glass in my 1965 home. I had read a question here that talked about window quilts and that eventually led me to the idea of covering windows with bubble wrap.
Much of my glass including large sliding doors etc are all bare aluminum frames without thermal breaks or insulation. The idea of adding a semi-clear covering that admits light and I can apply over the glass and frame is pretty appealing.
Of course replacing the windows is a huge expense. Some have single pane and others are double pane from 1965.
(Apparently greenhouse owners have been doing this for years.)
My question is, how would one best measure the value of this concept? I have read some r value estimates but I am suspicious. When I use my temperature gun on a piece of tape attached to the bubble wrap and a similar window without, the temp difference is only about 3-4 degrees. But my sense, based on how the room feels, is there is a lot more to this concept.
I can see how convective losses are reduced, radiative losses and gains are the same except when the sun is shining? Conductive losses are reduced? R value just seems too simple.