Condo Conditioned Crawlspaces - Ventilation?

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?

I like closed Crawl spaces . Please read all below

http://www.crawlspaces.org/

I’m the opposite…I like conditioned crawl spaces.

And did you read all below???

I do not want cold air in winter making floor cold I do not want 90° F moist air in summer making CS wet from cool 55° f .

Why do like Conditioned CS

I think we both want the same thing

Clarifications & News:

  • Turns out our crawlspaces are connected in pairs (not all 4 together).
  • Vents will not be cut in floor, but don’t know if they intend to cover existing ones (when we got a new furnace & our vent was sealed and a pipe installed directly from combustion chamber to crawlspace).
  • A duct will be installed on the plenum of each furnace to direct heated/cooled air into crawlspace. I don’t know of any plan to replenish extra air required for this.
    OwensCorning FOAMULAR 150 2" rigid extruded polystyrene insulation is being installed.
    The ducts in the crawl are flex type (don’t know about insulation).
    I am awaiting info on local regs re connected crawlspaces…

Needless to say, I have more questions about heating the crawlspace - especially since it connects to my neighbor. The mgmnt company rep sent me “conditioned crawlspace” info that extolls the advantages of (essentially) heating our floor. But since our floors are probably osb or plywood and covered with carpet, how much good is it going to do for the living space?

Thanks for all the input - a great help.

I would think if Moma has cold feet she will love you if you heat the crawl space Big time . How about just puting a plastic hanging wall to help close your section in . just a liile more heat will make huge difference to floor

What is a “plastic hanging wall”?
If all our first level floors are plywood or OSB and covered w carpet, how much warmer would anybody’s toes be? Wood and carpeting are not very good conductors of heat. right?

What is a “plastic hanging wall”?
If all our first level floors are plywood or OSB and covered w carpet, how much warmer would anybody’s toes be? Wood and carpeting are not very good conductors of heat. right?

What is a “plastic hanging wall”?
If all our first level floors are plywood or OSB and covered w carpet, how much warmer would anybody’s toes be? Wood and carpeting are not very good conductors of heat. right?

We learned for the first time from a worker that a duct would be installed to the plenum on the bottom of our furnace to supply conditioned air to the crawl.

Email reply from county buildings department:

  • “Apartment construction allowed crawlspaces to be connected assuming that the floors over the crawlspace had a one hour floor/ceiling assembly…”
  • “combustion air grills should be fitted with a fire damper”
  • “foam plastic insulation shall be protected against ignition…” (I have heard fire-retardant paint will be acceptable)
  • crawl “shall be continuously supplied with a minimum of 1.0 Cubic Foot per Minute of conditioned air per 50 Square Feet of under floor space”
  • “No permit is required.”

Question to forum:
Apprx 1000 sq ft crawlspace- so, 1 CuFt x 20 = 20 cu ft/min? How do I find out if our furnace/AC is delivering this?
We have a newly installed Bryant Evolution System Plus 95s Gas Furnace. Some (most?) of our neighbors will have 19 year old, less efficient furnaces.

We met with 3 members of our HOA board re the crawlspace remediation -
Q: Who is the designer/expert of the crawlspace modifications?
A: A professional crawlspace remediation company submitted a line item bid. It was very high. They copied the line item list and submitted it to (2?) other companies.
Specific questions about the design (how return air would get back from the crawlspace to the furnaces, etc.) were met with the same answer: The work is being done properly and “according to code.”

Q: Are you going to ask the other owners for permission to alter their plenum/heating system?
A: No response.
Their basic reply to these type questions was that the crawlspace upgrade was approved at the July membership meeting. That no minutes have been distributed and that numerous members missed the meeting did not appear to concern them.

This job apparently does not require inspection by building department, but (we think) the HOA agreed to ask if the department would be willing to do it if asked.

We said our concern was about whether our furnace would still work efficiently and also concerned about the quality of the air we will be breathing.

Sorry if I haven’t addressed all questions posted here (figgered this post was overly long already).