Humidifiers and Dehumidifiers - Basement Humidity: To Ventilate or Not?

I'm planning to finish my basement, which is humid in the summer months (northeast climate: cold winters, hot muggy summers).

A local home rennovating expert advises this simple system to dry damp basements in the summer. You can buy packaged ventilating dehumidifiers for a lot more money, but this simple solution is essentially the same. But I have a few questions at the end:

In a nutshell, his idea is that cold air is moister and heavier than warm air. Cool air falls to the lowest point in the house, the basement floor. If this air can be exhausted to the outdoors before it condenses with warm air, the basement will be drier and have less mold and musty odor. A 250 CFM duct fan is installed in a 6" duct that runs vertically on a wall to within a few inches of the floor. The other end of this duct is vented directly outdoors or tied into a dryer vent with a 'Y' connection. The duct should be at least 6' away from combustion sources (gas furnace or water heater), to avoid backdrafting combustion gasses into the home. The duct joints should be well sealed. The duct fan is set up with a timer to run only for 12 hours after 9 p.m. so that the cold, moist basement air is not replaced with humid daytime outdoor air.

Sounds good, but doing some research on the Internet regarding the packaged units, some critics think that these ventilating dehumidifiers will pull in too much humid outdoor air to make up for the air that the fan is expelling from the basement. It will come in every crack or crevice from all floors and into the basement, thereby actually making the rest of the house more humid and damp?

What do you think?

Other questions:

What about backdrafting/negative pressure for combustion appliances?

If you have a fresh air intake for the furnace, won't humid air come right in through it?

I have not heard or seen of such thing.. If this is exhausting to the outside, it has to be made up. If if the made up air that is drawn out of the basement will more humid if it's a very humid weather out side. I'd stay way from that whatever system that is.

If you got central air, just open up the vent(s) like I said in the other post you've got.

if you got the link for this set up, I'd like to see it....

Thanks for response, Jay.

The DIY system I described above is essentially like these packaged units, except the packaged units run continuously whereas the solution proposed by my local renno expert runs on a timer at night:

http://www.humidexatlantic.com

http://www.ezbreathe.com

I am sorry, I think those system are a joke.

With this system running, the lost air has to be brought into the house. Leaking though a window, attic, door.. Hey, you were worried about humidty coming into the fresh air vent in your furnace room.... It'll come in there as well!

Just as long you got air movement in the basement you should be fine. One sight says this; "lack of airflow through the home is being linked to severe health concern"

If you are concern about having fresh air in your home look into this. http://www.lifebreath.com/life.htm

With this system It'll remove the heat/humdity from the summer air, and also warms up the cold winter air.