Whole house ventilation system

**Trent Tarter** · 01-09-2013, 07:57 PM

Home was built in 1994, has a whole house ventillation system that's connected to the HVAC ductwork. I have never seen one with an air intake vent installed in the crawlspace. This just looks bad, drawing musty air from crawlspace into the home. I am guessing that the vent was intended to be routed outdoors.

Similar Threads:

**Scott Patterson** · 01-09-2013, 08:36 PM

Originally Posted by Trent Tarter

Home was built in 1994, has a whole house ventillation system that's connected to the HVAC ductwork. I have never seen one with an air intake vent installed in the crawlspace. This just looks bad, drawing musty air from crawlspace into the home. I am guessing that the vent was intended to be routed outdoors.

Is that by chance a sealed crawlspace?

**Trent Tarter** · 01-09-2013, 08:47 PM

No it's not a sealed crawlspace. Standard vented crawl.

**Raymond Wand** · 01-10-2013, 04:59 AM

Looks like a motorized damper which has not been wired in, which means its not functioning as per intended use.

David Bell · 01-10-2013, 06:30 AM

Looks like it could be a dump damper that would tie into the zone panel.

**Lon Henderson** · 01-10-2013, 06:31 AM

We don't have contraptions like that around here, but,in general, mixing crawlspace air into the home air seems like a really bad idea for several reasons.

**Jerry Peck** · 01-10-2013, 05:04 PM

Originally Posted by Lon Henderson

We don't have contraptions like that around here, but,in general, mixing crawlspace air into the home air seems like a really bad idea for several reasons.

Agreed ... it is a really, really, really stupid idea to take air from the crawlspace and suck it up into the living space ... unless the crawlspace was lined and being used as a return air plenum (which is still not real smart), and in which case it would not be 'fresh air' anyway.

**Trent Tarter** · 01-10-2013, 05:31 PM

Yes it's definitely not a good idea to pull air from crawlsapce into the home. I am recommending an HVAC contractor evaluate and repair. The damper was connected to low voltage wire. I see these types of air exchange systems installed in homes built in the early 90's. Typically the electronic damper is connected to an exterior vent.

**Jim Luttrall** · 01-10-2013, 06:34 PM

Not meaning to insult your intelligence, but are you sure it was on the air return and not the supply?
I could see having a supply duct ala' Dr. Joe in a conditioned crawl space.

**Jim Luttrall** · 01-10-2013, 08:00 PM

Originally Posted by Kevin Wood

As Raymond said it is a damper system for fresh air to outside not the crawlspace. This is usually hooked up to a HRV or ERV on the return and they may not have gotten the unit installed or just did not set up the supply to outside yet.

I think you mean Trent, not Raymond. Yeah, I saw that but I was asking if he was SURE it was on the return, not supply side.

With the screen it looks like this was an intentional installation, not an oversight.

**Trent Tarter** · 01-11-2013, 01:03 PM

Originally Posted by Kevin Wood

Temporary screen to prevent possible nesting until the full fresh air vent is installed.

That's what I was thinking.

**John Kogel** · 01-11-2013, 08:48 PM

Originally Posted by Kevin Wood

Temporary screen to prevent possible nesting until the full fresh air vent is installed.

Originally Posted by Trent Tarter

That's what I was thinking.

Temporary since '94, yeah, right.

Most people are pretty clueless when it comes to HRV systems. I find them turned off more often than not and the intakes are stuffed full of sticks and leaves.
I rarely find them in the new houses. It was like a passing fad in this climate. We can just open a window to get fresh air, why not, eh?