a return and supply w/ dehumidification in and unsealed basement/crawl? WTF?

[Efficiency1st]

So I've already asked a few people locally and talked to someone at Southface in Atlanta but I like getting input from all sources. Here is the situations:

Old, extremely leaky house (9000 CFM @ 50Pa), 2500 sqft. with 2nd floor heat pump, 1st floor gas furnace (both high efficiency for installation date) 2.5 ton, 3 tons respectfully. There is a return grill and a supply in the basement/crawl (basement or cellar in middle with crawl around the perimeter). This obviously insn't a sealed crawl or vapor barrier put down. The basement temp was -10 degrees from temperature in house and humidity levels - 5%. So while the dehumidification is working, the basement isn't well sealed enough to be considered conditioned space...Not to mention, that homeowner is paying an a$$ of money to condition and dehumidify a leaky basement, in addition to a leaky home when they could have just kept the dehumidifier and used that to mitigate the RH that would come up form the crawl. O and the duct leaked at over 50% on BOTH floors (even though second floor duct work was re-installed with new system)

to my questions: i understand the philosophy the HVAC installer may have had, but who really wants air from their basement/crawl being redistributed into their home? I know there is a "filter" but come on. Any other philsophy's out there...anyone want to take this guys defense?

[FlyersFan]

From your description, it sounds like a typical older Atlanta home. Partial basement surrounded by crawlspace. The real question to ask is whose decision was it to put a supply and return in the basement? Maybe it was someone's workshop in the past or a previous homeowner had them installed for reasons of their own regardless of an installers suggestions not to.

Is this a new install?

[Efficiency1st]

From your description, it sounds like a typical older Atlanta home. Partial basement surrounded by crawlspace. The real question to ask is whose decision was it to put a supply and return in the basement? Maybe it was someone's workshop in the past or a previous homeowner had them installed for reasons of their own regardless of an installers suggestions not to.

Is this a new install?

Good question. There was no obvious suggestion by the workorder but I appreciate the question, thats the scenario playing I needed so I don't seem like I'm attacking the hell out of this HVAC contractor.

But you do agree, this makes no sense in any case? Only exception is if the crawl were encapsulated, sealed; which would be good for IAQ, and controlling humidity issues....

[FlyersFan]

I'm assuming that, from your first post, that you do some sort of house testing similar to South Face's Home Performance program. If the ductwork in the basement/crawl area is an issue that you're adding to your list, just recommend taking it out if the homeowner doesn't have any objections. I wouldn't make too big a deal of it.

As far as it making sense - I don't know, haven't seen it. It obviously made enough sense to someone that they put it there.

[air2spare]

So I've already asked a few people locally and talked to someone at Southface in Atlanta but I like getting input from all sources. Here is the situations:

Old, extremely leaky house (9000 CFM @ 50Pa), 2500 sqft. with 2nd floor heat pump, 1st floor gas furnace (both high efficiency for installation date) 2.5 ton, 3 tons respectfully. There is a return grill and a supply in the basement/crawl (basement or cellar in middle with crawl around the perimeter). This obviously insn't a sealed crawl or vapor barrier put down. The basement temp was -10 degrees from temperature in house and humidity levels - 5%. So while the dehumidification is working, the basement isn't well sealed enough to be considered conditioned space...Not to mention, that homeowner is paying an a$$ of money to condition and dehumidify a leaky basement, in addition to a leaky home when they could have just kept the dehumidifier and used that to mitigate the RH that would come up form the crawl. O and the duct leaked at over 50% on BOTH floors (even though second floor duct work was re-installed with new system)

to my questions: i understand the philosophy the HVAC installer may have had, but who really wants air from their basement/crawl being redistributed into their home? I know there is a "filter" but come on. Any other philsophy's out there...anyone want to take this guys defense?

we call that hackery in our neck of the woods

[teddy bear]

No matter how you try, you will not stop basement air from moving out through the top of the home during wind and stack effect. So, stop musty odors and clean up the space. Plastic on the earth, close the vents/seal air outside air leaks, keep the space <50%RH, and relax. Get a good +90 pint per day dehumidifier, like a Santa Fe Advance etc to avoid moisture that will grow biologicals during damp weather. The basement can be useable space. Regards TB

[Efficiency1st]

we call that hackery in our neck of the woods

air 2 spare, can you put hackery into non-texan terms? being from the south I thought I'd heard them all but you texans have a world of your own...

[duckman373]

In NC it would be called bo-bo. Is that close enough to Georgian speak?

[air2spare]

air 2 spare, can you put hackery into non-texan terms? being from the south I thought I'd heard them all but you texans have a world of your own...

hackery is not texan-ese, you'll find the term used throughout our industry

[doc havoc]

Maybe it was someones lame attempt at increasing cfm through improperly sized ductwork?