Can any solar film raise the R Value by 1 point?

[cooltinter]

Hello smart people, hope everyone is doing ok in these crazy times! 

 

I received a call from a commercial glass company who are looking for a window film that will raise the R-value of their triple pane units by 1.

The exterior pane being heat treated. The other two interior panes are regular annealed glass. There is a low-e coating on surface #2 (starting from outside)

They would like to keep the look of the glass as neutral as possible, if possible.

The larges panes are 54-1/2” x 72”.(approximately 60 panes)

If there is such a film, I would need to submit something tangible that would show the science.behind the madness.

Any info on this would be much appreciated.

 

thanks so much everyone, stay safe!!

[Tintcutter]

R value is the U value of a material divided into 1 as a standard so that commonality can be found across dissimilar materials. U value is a percentage because flow rate of energy is important but actual degree measures are not useful.  A brick has an R value of 4. Why? Because 1/.25=4. The U value of a brick is 25%. that means 4 degrees go in one side and 1 comes out the far side. Or 40 go in and 10 come out or 100 go in and 25 come out. U values on products like Enerlogic are given around .62 these days. 1/.62=?. So in the overall measurement of the R value of a window of course the frame comes into play. The frame is roughly 25% issue, made problematic by the reality that the more solid a material is then also the better it conducts and holds energy due to its mass.

 

If you did the little math I left for you then you should also know that R values of materials are sums. They add together like you wearing multiple shirts.

Edited May 20, 2020 by Tintcutter
spelling as usual

[Tintguy1980]

Most films make available technical performance value sheets with one parameter being the U-value. They usually

list all their films and at some location on that sheet will give the values of glass before film is applied.