Crawl space fan is causing smell coming from attic?

[James E. Braun, CMI]

You would think.

[ROBERT V. YOUNG]

Sorry but Ron has a good point here.Cooke to has good answer but I am getting confused to get my head around the question in full .To many answers, to many building possibilities.

[measter]

Sounds like many on this thread are confused.

The crawlspace ventilators mentioned are low flow and low pressure. I think we are looking at about 5 Pa.

The ventilated crawlspace needs to sealed with respect to the outside. That may sound contradictory, but you can't draw hot, humid air from the outside and cool it in a crawlspace and expect it to dry. The exact opposite of drying will happen if the crawlspace isn't ventilated. The existing crawlspace vents must be sealed.

Yes this will draw conditioned air from the building into the crawlspace. It's not as much of an energy waste as you might think. Many homes have uninsulated basements that run dehumidifiers all the time. Some basements are at least partially conditioned and aren't occupied. In fact, this type fan could actually retard some of the stack effect losses which are greatest at the attic interface.

These fans could not pull smells from the attic. They just can't generate enough static pressure. That logic just doesn't hold.
1. A damp and moldy crawlspace stinks.
2. The stack effect will draw crawlspace air into a home
3. The house now stinks like mold.

A crawlspace ventilator can reverse this. It sounds like the "attic smells" excuse is just an invalid conclusion thrown out so that they don't have to stress their minds with different information.

The problem with your ventilated crawlspace "theory" is with your logic.
The problem with your logic is this: when it works then they can't sell waterproofing services!! So obviously your idea is flawed since it doesn't fit their business model of selling expensive services.

And I just don't see many attics that smell worse than the crawlspace.

V/R
Mark

[ROBERT V. YOUNG]

Could you not use a smoke pencil to find where the back drafting is coming from.The home will be uninhabitable if this persists or might already be.
I installed turbine vents for this very purpose and reason being that the home was not venting properly.IE: same story but non sealed building.
The turbine would have a pot installed directly underneath it and would be equipped with up to 4 mounts to attach a 1 to 4 inch hose (styled like a dryer hoes only more rigid but allowing them to be able to be fished through wall or bulkheaded and installed where they where needed.The vent would be able to be opened and closed and adjusted for whatever desired drafting and air flow was required.
Sounds like this building should have adjustments to its venting problem for it already sounds unhealthy to live there.
When was the residential building constructed.Might have been the infancy of that type of building practice and errors were made by contractor.