Duct Booster

[Bain]

My sister and brother-in-law just had their house inspected in Denver, and the guy checking out the house left the drywall off this access hatch in the basement. My brother in law called to ask what the purpose of the electrical device--which is a fan, he discovered, after he inserted the plug--was and I wasn't sure.

The top of the duct terminates into a backdraft damper on the exterior of the house, but he's unable to see down through the chase to determine where the duct originates. The basement floor is concrete, of course, and there are no bathroom fans or laundry facilities nearby.

Any ideas?

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[Erby]

Colorado radon mitigation system??

I hear there's a bit of radon around there.

-

[Rocon]

Confirmed it is a radon gas ventilator.

[Bain]

Interesting.

My brother in law suggested the same thing, but the system isn't airtight, there's no manometer, and the backdraft damper is probably beneath windows. I told him I didn't think so.

Is this what early mitigation systems looked like, Rocon?

[Bill Kibbel]

If that's a radon mitigation system, everything is wrong with it.

[hausdok]

Hmmm,

Has Gromicko worked on that house? He lives in Colorado now, doesn't he?

OT - OF!!!

M.

[Chad Fabry]

Who's Gromicko?

[hausdok]

Hi Chad,

Gromicko is a guy who used to install radon mitigation systems in the State of Pennsylvania. He got into trouble when he cheated his customers by not installing those systems correctly. It seems the Pennsylvania Department of Environmental Protection, or whatever it's called there, inspected a system, found it to be faulty, and then decided to randomly sample a set number of the systems that he'd installed. Well, not a single one inspected was installed correctly so they suspended his radon mitigation system installer's license and levied a hell of a big fine on him - more than $14,000. Gromicko wasn't going to take that lying down, he appealed it all the way through the Pennsylvania court system,.....and lost. So, after installing many faulty mitigation systems, being caught, fined, taking it to appeal and losing - while all the while those systems were probably harming the health of families and children living in those homes - did he go back and fix those systems or even pay the fine? Nope, he moved to the State of Colorado and claims that he doesn't have to pay the fine. It remains unpaid to this day. What a fine upstanding citizen - NOT - I'm picturing a horse's ass with teeth.

Oh yeah, he's also the guy who founded and owns a public relations firm that passes as a home inspection organization which he claims is the world's largest - another lie; anyone with a thimbleful of brains knows that the Royal Institute of Chartered Surveyors - R.I.C.S. - is the largest organization of home inspectors in the world and has been for more than a hundred years. However, given his track record, I doubt that he cares about the truth.

Last I heard, he's living in Ned, CO. Maybe he's getting back into the radon mitigation system business.

ONE TEAM - ONE FIGHT!!!

Mike

[msteger]

Originally posted by hausdok

Oh yeah, he's also the guy who founded and owns a public relations firm that passes as a home inspection organization which he claims is the world's largest - another lie; ... Last I heard, he's living in Ned, CO. Maybe he's getting back into the radon mitigation system business.

Great analysis of his 'club', Mike. Couldn't have said it better myself.

From what I've heard from several people, the individual in question has still never paid his fines and is still 'on the run' from the PA DEP claiming he has done nothing wrong. What a joke. From documents I have obtained (from very reliable sources), this individual does still live in CO.

Radon mitigation fans can only be installed in attics or outside the home. They can not be installed in basements, inside wall cavities, etc. Not sure what the fan in question is, but if it is for a radon mitigation system, it is very wrong. Several local people putting themselves off as "radon remediators" (and are anything but) have been caught by the PA DEP, but skipped town before anything could be done. Too bad...

[Garet]

It's not a radon system.

Most likely they have a structural floor in the basement, consisting of framing with joists (either wood or metal) and OSB floor sheathing. We sometimes also construct them with structural steel beams and a cast concrete floor. Either way, there is a crawl space below the basement floor. This fan is part of a mechanical ventilation system intended to remove moisture from the crawl space (although they also tend to flush out radon). Most of these structural floors (...but not all) have an access hatch into the crawl space.

The fan wiring and plug look hokey. They're normally hard-wired with armored cable to a j-box on the side of the fan.

Garet Denise

Denver, CO

www.Cornerstone-Inspection.com

[Neal Lewis]

Originally posted by Chad Fabry

Who's Gromicko?

Just conjecture, but I don't think there's too much Chad doesn't know...

[Tom Raymond]

Originally posted by Garet

It's not a radon system.

Most likely they have a structural floor in the basement, consisting of framing with joists (either wood or metal) and OSB floor sheathing. We sometimes also construct them with structural steel beams and a cast concrete floor. Either way, there is a crawl space below the basement floor. This fan is part of a mechanical ventilation system intended to remove moisture from the crawl space (although they also tend to flush out radon). Most of these structural floors (...but not all) have an access hatch into the crawl space.

The fan wiring and plug look hokey. They're normally hard-wired with armored cable to a j-box on the side of the fan.

Garet Denise

Denver, CO

www.Cornerstone-Inspection.com

Why would one want such a structural floor in a basement?

What purpose is served by the sub-basement?

If that hokey get up (but at least they used "duck" tape to seal the connections[:-banghea) is to vent the sub-basement, why would it be hidden behind an access cover and not installed in the open like the rest of the mechanicals?

Isn't mechanical ventilation of that type required to be automated with thermostat/humidistat type controls?

Tom

[Garet]

Why would one want such a structural floor in a basement?

What purpose is served by the sub-basement?

GD: Because we have expansive soils here that can heave the a slab-on-grade floor up. I've seen the soil move several inches. Interior partition walls would push up on the first floor framing and wreck the house. With the structural subfloor the soil can heave upwards and not affect the structure; the crawl space just gets a little shorter.id="blue">

If that hokey get up (but at least they used "duck" tape to seal the connections[:-banghea) is to vent the sub-basement, why would it be hidden behind an access cover and not installed in the open like the rest of the mechanicals?

GD:Mechanicals are often located in the center of the basement. Ventilation works best when you pull from the edges. There should be a complementing inlet air pipe on the opposite side of the basement. Since the inlet pipe has no serviceable parts it could be hidden behind finished wall surfaces with no access. id="blue">

Isn't mechanical ventilation of that type required to be automated with thermostat/humidistat type controls?

GD:The humidistat is normally located at the crawl space access hatch where the homeowner can adjust it easily.

Garet Denise

Denver, CO

www.Cornerstone-Inspection.com id="blue">

[Erby]

From the OP:

this access hatch in the basement.

The basement floor is concrete, of course

I'd still bet on a hokey attempt at a radon system.

[hausdok]

Hi,

I think Garet's explanation makes the most sense. There is a lot of bentonite in Colorado and I remember that years ago someone from Colorado, perhaps it was Garet, posted a photograph of one of those Colorado crawlspaces under a basement on the ASHI members' forum and explained the system to everyone. Since those are below the basement floor, one has to have some way to get all of the moisture that's evaporating out of that clay out of that crawlspace and an in-line fan like that is probably a good way to do it. Of course, that still doesn't account for how they're dealing with radon. Perhaps that area of Colorado is like most of Washington State where they don't regularly install radon mitigation systems, in anywhere other than Spokane or Vancouver, because radon levels are so low. I'm left wondering whether it's a high speed or low speed fan.

ONE TEAM - ONE FIGHT!!!

Mike

[Erby]

We ain't there and Garet will be more familiar with the usual but two notes:

From the Original Post:

The basement floor is concrete.

From Garet's post:

Most likely they have a structural floor in the basement, consisting of framing with joists (either wood or metal) and OSB floor sheathing.

[hausdok]

Hi Erby,

Yes, that's true, they do have framed structural floors there but they also pour reinforced concrete floors over a crawlspace so that the basement floor is concrete and the crawl is, well, a crawlspace. That's what I'm referring to. What, you've never had a crawlspace under a concrete floor? Jeez, you're in Shangrila, Man! I've done my share of those even here in Seattle - usually under detached garages; one was under an attached garage.

OT - OF!!!

M.

[Bain]

I sent my brother in law a link to this thread, and he's been checking in. He's pretty certain there's no crawlspace due to the grade, etc.

Of course, he could be wrong.

Why go to the extra time and expense to create a crawlspace beneath a concrete floor, Mike? Why not just throw down a slab?

[hausdok]

Originally posted by Bain

I sent my brother in law a link to this thread, and he's been checking in. He's pretty certain there's no crawlspace due to the grade, etc.

Of course, he could be wrong.

Why go to the extra time and expense to create a crawlspace beneath a concrete floor, Mike? Why not just throw down a slab?

Because of the bentonite! The crawl gives the clay the ability to expand upward and/or drop away, depending on weather and ground wetness, without heaving the floor or causing it to cave in.

I know this is hard to wrap your mind around; it was for me too when I lived in Colorado Springs, but that's the way it is.

Tell your brother-in-law to look around for what looks like a square scored on the concrete floor, put the tip of a flat bar into that groove, give it a whack and then pry up - verrrry carefully, or he'll lose it into the hole.

ONE TEAM - ONE FIGHT!!!

Mike

[Bain]

Ahhh . . . . . .

I must admit I know nothing about bentonite. I quickly Googled it and curiosity will no doubt lead me to learn more.

As for my brother in law's house, it's sold, and his interest level in his soon-to-be former abode is likely nonexistent. Besides which, the basement floor is covered with carpet.

The repair-request form has already come back, and apparently no mention was made about the duct fan in the photo. Interestingly, the buyer's inspector detected CO somewhere and the buyer asked for a home warranty should the furnace go bad. I elected to keep my mouth shut and said, "Just so."