Doesn't seem to work.
In[5]:= Needs["NDSolve`FEM`"]
In[8]:= \[CapitalOmega] =
ImplicitRegion[! ((x - 5)^2 + (y - 5)^2 <= 3^2), {{x, 0, 5}, {y, 0,
10}}];
In[11]:= op = -Laplacian[u[x, y], {x, y}] - 20;
In[9]:= Subscript[\[CapitalGamma],
D] = {DirichletCondition[u[x, y] == 0, x == 0 && 8 <= y <= 10],
DirichletCondition[u[x, y] == 100, (x - 5)^2 + (y - 5)^2 == 3^2]};
In[13]:= res =
Reap @ NDSolveValue[{op ==
0, {DirichletCondition[u[x, y] == 0, x == 0 && 8 <= y <= 10],
DirichletCondition[
u[x, y] == 100, (-5 + x)^2 + (-5 + y)^2 == 9]}},
u, {x, y} \[Element]
ImplicitRegion[(-5 + x)^2 + (-5 + y)^2 > 9 && 0 <= x <= 5 &&
0 <= y <= 10, {x, y}], EvaluationMonitor :> Sow[{x, y, u[x, y]}]]
Out[13]= {InterpolatingFunction[{{0., 5.}, {0., 10.}}, <>], {}}