The Wife & I have lived in our home for over 20 years now and the one persistant problem I have in the lower level of the house in the laundry / furnace room is; BLACK MOLD. We have always maintained an extremely clean home. However, this is one thing I just can not get a handle on. This mold is only on my PVC plastic plumbing pipes, (because they sweat) it's not on the walls or anywhere else only the pipes. Mostly on the cold lines but sometimes on the hot lines too. During this time of year when the humidity is high is when it starts. The A/C runs at a constant 78 year round with the blower set on manual instead automatic so I know we have good air flow into this room. I usually take a 5 gal. bucket and fill it half way and then add 1 gal. of bleach to the water and proceed to wipe them down. This will end the problem for this year but as always, I'm sure it will return next year! Any suggestions on how I can be permanently rid my self of this ongoing problem? Thanks in advance for your help. Wayne