DeHumidifier / Condensation

:hide: We had a New Propane Fired Furnace installed last December and added a cold air return in the basement.. We have issues with Dampness in the Basement and have a portable dehumidifier running in the off peak hours.. Now with the Fall Temps dipping now on the minus side at night.. Colder outside than Inside, wake up to condensation on the kitchen / livingroom windows. Looking for Tips or Ideas to keep the Condensation at Bay..:help:

I would close that return in the basement for a coupe days to prove that it is the basement causing the problem.

nealtw said:

I would close that return in the basement for a coupe days to prove that it is the basement causing the problem.

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. Mon. / Tues. Woke Up to Minus 3C' (outside) Condensation on Livingroom / Kitchen Windows (open concept)... Wed. morning woke up to Plus 3 , No Condensation on the Windows.That's without Basement C/A return not. Closed Off. Furnace is set @ 19C'...

Question: Having replaced the Oil Furnace for a Propane Furnace. Would the New 2 PVC Pipe (exhaust / vent) have any bearing on the Condensation Issue ??

I wouldn't think so but. Have you increased the BTUs, changed ducting other that adding the return in the basement.
Did the old system have a fresh air intake that is now closed off. Or have you now got more humidity than you have ever had before , like a leak somewhere, plumbing or roof that you have not noticed yet.
Is the new furnace venting properly to the outside, is there a leak in that run.?

nealtw said:

I wouldn't think so but. Have you increased the BTUs, changed ducting other that adding the return in the basement.
Did the old system have a fresh air intake that is now closed off. Or have you now got more humidity than you have ever had before , like a leak somewhere, plumbing or roof that you have not noticed yet.
Is the new furnace venting properly to the outside, is there a leak in that run.?

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:hide: Changing from Oil to a New Propane Furnace the Chimney if you will has been changed to 2 PVC Pipes (exhaust & vent) exiting the side of the foundation.. The Duct Work was not changed other than the added Cold Air Return in the Basement.. Because of No Kitchen Exhaust directly to the outside , likewise for the Bathroom.. It's a given Condensation will form on the Livingroom / Kitchen windows when doing some serious cooking.. Yes it has become more noticeably with the new Furnace Setup , but after rooting through the storage room in the basement back beginning of Summer we noticed quit a bit of mold on some clothing hanging on the racks..... @nealtw.. Thanks for the Comeback, I suppose jacking the T-Stat up a few more degrees could help.. The Wife is talking she'd like to look into a Gas Fireplace (Wall Insert) for the Basement... Just need to Win the Lottery..lol..

The moisture causing the mold may not have been there last year, so maybe the furnace has nothing to do with the furnace..
Ya the new furnace is closed system, the old furnace had an air supply and a chimney and when that old one was working the exhaust likly drew moist air along with it.
Find the source of the moisture in the basement? Look at fan in kitchen, there are answers. It's just a matter of having the right questions.

nealtw said:

Find the source of the moisture in the basement? Look at fan in kitchen, there are answers. It's just a matter of having the right questions.

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:agree: Pre Installation of New Furnace the local company we dealt with the Owner sounded pretty Knowledgeable.. It's the Cost of Goodies they can pull out of their Sleeves that can do some serious hurt to the wallet..lol..

According to Records this House the Original Foundation & Framework was built in 1973 and in 1993 the Owners at the time knocked down & moved some walls.. We bought in 2007, yes we've found some surprises.. The Kitchen Fan / Hood is one of those Electric Exhaust Fans to Nowhere.. And No Bathroom Fan,with the pitch on the roof we'd need a Midget access the crawl space.. The Exhaust & Ventalation Theory has me wondering..Is there Not enough Venting / Air Circulation??? This House holds it's Heat well, on several occasions in the dead of winter Hydro Out for several hours the Heat will only drop a degree or two..

That is what I would be looking at.The tighter the house the bigger the problem. In the newest houses here they have a fan in the upper hallway running all the time, pumping heat out and they have all the other fans too.
Do you have access to the attic as bad as it is, what is on the roof, torch down, tar and gravel or?
Have you thought about a wall unit for the bathroom? Soffet vents would have to be protected but it is an option.
Same with the kitchen?
Do you have a brick chimney and is it being used now for anything?

nealtw said:

Do you have access to the attic as bad as it is, what is on the roof, torch down, tar and gravel or?
Have you thought about a wall unit for the bathroom? Soffet vents would have to be protected but it is an option.
Same with the kitchen?
Do you have a brick chimney and is it being used now for anything?

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Shingled Roof, access through the Master Bedroom Ceiling.. Finished Basement , Main Floor .. House is 938 sq ft.. The Chimney was Capped @ The access point Inside Basement Wall.. There was a Flex Pipe Sleeve installed back 2008....

The old furnace had a fresh intake that just ended somewhere near the furnace, was it capped off too.
So with a shingled roof, you have at least a 4/12 pitch giving you 4 ft in center of attic, bathroom fan is possible.

Explain why we can't get a hood fan duct to an outside wall. Where is the range to the outside or to the center of the house.

nealtw said:

The old furnace had a fresh intake that just ended somewhere near the furnace, was it capped off too.
So with a shingled roof, you have at least a 4/12 pitch giving you 4 ft in center of attic, bathroom fan is possible.

Explain why we can't get a hood fan duct to an outside wall. Where is the range to the outside or to the center of the house.

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The New Propane Furnace (HE Lennox) took up less space consequently they redid the Plenum when they removed the old Oil Furnace.

The Hood Fan is on an Inside Wall, Cupboards both sides.. Duct work would have to go through about 6' of cupboard space to an outside wall.. :hide:

The old funace should have had a duct from out side they called it something like fire air, was that there too and is it gone now?
So the range at 6ft from the outside wall, should be able to vent it thru the roof. as it is more than half way to the center of the house..
How close to the center of the hose does the bathroom get to.

nealtw said:

The old funace should have had a duct from out side they called it something like fire air, was that there too and is it gone now?
So the range at 6ft from the outside wall, should be able to vent it thru the roof. as it is more than half way to the center of the house..
How close to the center of the hose does the bathroom get to.

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:2cents: Yep.. With the New Installation the original pipe which had a Short Elbow type Trap Door like Flapper that lead from the O/F to the Wall is gone..

As for the Bathroom & Kitchen Exhaust.. The layout of the Bathroom and the Inside Wall for the Kitchen Fan are pretty much in the same line (??).

So you have a very tight house that holds the heat, no way for bad air or moist air to get out, and no fresh air coming in.
I think you need that fresh air intake and you should have at the very least a bathroom and range hood fan. But maybe you should take this info and post another question over in HVAC and get opinions there.