If this forum is open to non-inspectors:
Our condo HOA has hired a contractor to condition the crawlspaces in our attached 2 story 20 year old buildings located in south central Indiana (Bloomington). We have four connected first floor units that will be most impacted by the upgrade. The crawlspace below each unit measures approx. 1000 sq ft., but I believe all are connected via (just guessing) approx. 10’ opening in support walls between units. The space below my unit is very shallow, approx. 16-24" high. So, rounding things off- 2000 cu ft under each unit x 4 units = 8000 cu ft total crawlspace.
A new vapor barrier is being installed over the old and blueboard insulation placed on the cinder block walls. Some sort of sealing is being done to the floor joists and exterior vent blocked off with blueboard.
In the middle of each first-floor unit, a gas furnace is in a utility closet which opens into the great room. It has a 6x12" floor vent into the crawl space to draw combustion air for the furnace. I was told by a worker, if they don’t have this vent, one will be installed so that “air will circulate to the crawlspace.” I don’t understand this.
If our living space is always warmer than the crawlspace, how will air move down?
And if it did move down, would this small passive opening, be enough to take care of possible humidity/mold issues?
Finally, with the crawlspace being sealed from the outside, will there be sufficient air for the furnaces?