We have the following function. I'm trying to give this a functional name. Specifically what I'm looking for is a name to give $U_o$.
$U_o = \frac{(\Sigma (U_i * A_i))}{A}$ for $i = 1, n$
$U$ is a measure of resistivity ($U$-Value) of a window $A$ is the area of the window.
I understand the math. What I don't understand is what name to give it. "Total $U$-Value" and "Aggregate $U$-Value" don't feel correct.