Humidity And Condensation On Windows

Quartapound

Active Member
Joined
Oct 16, 2011
Location
Kitchener, Ontario
Hey everyone,

...So I moved into a new place this July. Never had condensation issues in my last place, but there was a fresh air duct that led to the furnace. This place doesn't have that.
  • Now that it's getting cold out I'm finding LOTS of condensation on the windows....
  • House is 2007, so it's probably reasonably airtight (part of the "problem" I assume)
  • Tank isn't that big, 45G display, ~15G sump, ~20G shallow frag tank about 70G total water volume.... but high turnover and lots of surface area for evaporation.
  • Relative Humidity on my thermostat seems quite low... time of this post it says 36%, yesterday it said 41%
I wiped off every window in the house yesterday and today it's just as bad... (worse because it's colder outside)

O78UhVEb.jpg


I'm plugging in the dehumidifier today.... very surprised because I had zero issues in my last place (which was just as new/airtight...although there was a fresh air intake) and I didn't think my tank was big enough to warrant these kinds of moisture problems!

...Anyone have any advice/tips/insights? ...I was hoping to not have to run the dehumidifier all winter :s
 

dale

Active Member
Joined
Jan 24, 2012
Location
Sarnia, Ontario
your furnace running more often will help... turn off the humidifier on the furnace. most have them.. and the dehumidifier will help too,,, i have less moisture in the winter..
 

Quartapound

Active Member
Joined
Oct 16, 2011
Location
Kitchener, Ontario
Exactly lol... I thought it was supposed to be more dry in the winter. No humidifier on my furnace. The problem is much more apparent on the second floor windows

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scubasteve

Distinguished Member
Joined
May 4, 2014
Location
Cambridge, Ontario
are they double pane windows or single? me and the wife live in a co-op so we have crumby single pane that are horrible and no freshair exchange either. i just turn off humidifier on furnace and keep tank down around 78. with that i get almost nothing unless -45 out then your scewed no matter what.... if that dont take care of it then plug in the dehumidifier but those things are power pigs. giant tigerused to sell these packs that pulled excess moisture out of the air they were great for under cabinet and cheap
 

Nighthawk26

Active Member
Joined
Apr 10, 2015
Location
Waterloo
Did your old house have an HVR? Newer homes almost all suffer from this. New code in Ontario as of this year, every new home must have one. The colder it gets, the more it's going to happen. Warm air meets cold panel glass, there you have it. It's not only about relative humidity.
 

Quartapound

Active Member
Joined
Oct 16, 2011
Location
Kitchener, Ontario
They're double pane windows, probably cheap ones though.

Tank temp is kept at 78.3 by the Apex

no HRV in the "old" house(built 09), but it had a fresh air duct that terminated near the furnace kinda like this
FreshAirDuct_Example2.gif


I may have to bite the bullet and install an HRV.... luckily I went to a training seminar by LifeBreath with my last employer, so I could probably install myself to save a few pennies.... PITA though.

Didn't realize they're making that mandatory code now! Probably a good thing... but new house prices will keep going up as a result... Recently adding mandatory smoke detectors/strobe lights in every bedroom already added a good chunk of $$...but I guess mold and fire are things most people would like to avoid lol
 

reef keeper

Super Active Member
Joined
Nov 19, 2014
Location
Hamilton, Ontario
Your tank in the basement? I bet your downspouts run into the weeping tile instead of away from the house.

That makes your walls damp. Which makes the insulation damp.

Which makes your basement humid
 

Quartapound

Active Member
Joined
Oct 16, 2011
Location
Kitchener, Ontario
Your tank in the basement? I bet your downspouts run into the weeping tile instead of away from the house.

That makes your walls damp. Which makes the insulation damp.

Which makes your basement humid

Funny, the previous owners, in their infinite wisdom, did exactly that. One basement corner (where the spout was) had obvious efflorescence. Helped us knock the price down. I routed all downspouts away from the house upon possession, called the crack doctor, resolved that issue.

My sump/frag tank is in the basement, display on the main floor.... no humidity on basement windows though, only on 2nd floor really.

relative humidity is still quite low though... I turned on the dehumidifier this morning, and it's barely running because it keeps reaching it's set point (35%) and can't be set any lower.
 

Bigfish

Member
Joined
Mar 18, 2012
Location
Kitchener, On
That fresh air near your old furnace was the way they installed them so there was combustion air being brought into the furnace room. Now, most furnace intakes are run outdoors, and even some water heaters have outside air intakes on them. I had to install an hrv in my home as the tank caused the windows to sweat so bad, it would pool on the sill and run into the floor. Fortunately I install HVAC for a living so the cost wasn't too bad.
 

reef keeper

Super Active Member
Joined
Nov 19, 2014
Location
Hamilton, Ontario
I'll bet around the window frames isn't spray foamed but stuffed with pink insulation. If it's cold around the windows then the air is leaking into the frame and chilling your inside pane. You will need to pull the window trim and remove packed pink insulation and use the WINDOW AND DOOR spray foam in a can.

That will seal it and solve the problem
 

chrisstevens

Member
Joined
Mar 30, 2011
Location
Sarnia, Ontario
Website
flybikes.wixsite.com
If you do the plastic over the windows it will prevent the seating on the windows by creating an air insulation blanket. Dosen't get rid of the moisture in the air, but prevents the condensation and mold growing.

I have same problem in my house, its a old house with single paned windows with storms, Sealed up to air tight with no fresh air coming in,no hrv. humidifier turned off, and 200gal fish tank and 75gal sump. I just recently took the insulation out of the old chimmy to let air able to escape from the house a bit and, did my upstairs windows and i have been fine. Needless to say i do plan on installing an hrv unit eventually.
 

Quartapound

Active Member
Joined
Oct 16, 2011
Location
Kitchener, Ontario
the windows near the tank (any of them on the main floor) are fine, it's just the ones on the top floor that are bad... maybe I'll have to pull off the trim one day and see if they cut a corner and used pink insulation instead of proper spray foam...

I might get a window shrinkwrap kit soon.... there were curtains in front that was also making things worse, removing them seems to have helped .

thanks to all those who commented!
 

Nighthawk26

Active Member
Joined
Apr 10, 2015
Location
Waterloo
Public service announcement:

If you are going to attempt to install an HRV yourself, PLEASE make sure you know what you are doing, and balance the setup properly, and consider all other exhaust vents in the house. Bathrooms, laundry rooms, hood range, etc, etc. Negative pressure in a home can be a major MAJOR problem.

Now back to your regular scheduled programming.
 

Quartapound

Active Member
Joined
Oct 16, 2011
Location
Kitchener, Ontario
Totally agree. Can easily poison your entire family if you don't know what you're doing. I spent a few days getting certified, and learning how to calculate things properly... Even then I'd still get my old boss to help if I were to go through with this (he's licensed HVAC/gas fitter and electrician... Good guy to know)

Not something to take lightly.

Thanks for making sure people know the severity of installing these systems

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Last edited:

Luke.

Distinguished Member
Joined
Jun 9, 2015
Location
Kitchener
Lol funny topic because I install windows and doors for a living . And there can be
A few possibilities with condensation and it can be as simple as poor window s put into the house , you said it was new but I'm not sure how much money you spent for the quality , a lot of contractors love to save a buck and jut make a house look nice if its 2007 im sure there in spray foam and im assuming your window is vynal there issue could also be the windows to tight and have next to nothing for insulation but I'll be honest 99% of people who call us back for brand new lifetime warrenty top line windows it's because they have drapes or blinds or even furniture pushed up over the floor heaters and the heat actually traps around the window and it'll cause a lot of condensation if that's not the case it's probably the windows. I've seen it many times you need minimum 1/4" all the way around your frame for insulation (spray foam is the best)
 

Quartapound

Active Member
Joined
Oct 16, 2011
Location
Kitchener, Ontario
I'm sure they're probably the cheapest 'builder special'... Gonna seal em up with shrink wrap this time... Might be due for an upgrade eventually :s

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