We continue to battle condesation in our newly constructed home much the same case as many others do. At the moment we are considering to install a 4" PVC pipe from the outside of the house to the cold air return duct nearest the filter on our forced air furnace. This of course for fresh air. In addition, I was also looking at installing a pipe to the combustion vents on the furnace. Would there be any draw backs by performing these two procedures. Would it do more harm then good? Will it remove the condensation we are experiencing? We were looking at installing a heat-exchanger/venilator into the house, but at the moment money is a little tight. Any idea's or opinuns?