I do indoor air quality assessments, which require me to inspect HVAC systems. I came across an old Williamson Oilsaver--the condensate was draining onto a concrete slab (no floor drain), causing mold to grow on the interior walls of the room. I was curious what you pros would recommend to do? Also, what type of filter do you guys feel would work best? any web page links that would be helpful? I appreciate it.