Hello,
I'm looking to see how to remove excess humidity in my home. I had the windows replaced 3 years ago and still get a good amount of condensation on the windows in the cold months. The bathroom does not have an exhaust fan, so when someone showers we just pop the window open. As for the rest of the house, when I see the windows have alot of condensation on them I open some of the other windows a little until it goes away. My home heating system has a humidifier connected to it that I keep off, which I assume it should stay off? Besides installing a bathroom exhaust fan, should I buy a dehumidifier? Should I just keep opening the windows from time to time? Any input on how to stop the excess condensation would be helpful!

 

If you have a basement, Yes you should definitely have the largest dehumidifier you can afford. It usually makes sense to put it in the mechanical room where you usually have a floor drain and good ventilation.

If you don't have a basement most of the larger dehumidifiers have a bilge pump that can pump that water outside so that you don't have to dump it manually.

 

It is a finished basment, does that make a difference where to put the dehumidifier?

 

It would go wherever the floor drain, mechanical room or laundry room is located. If the room has a door that door either needs to be louvered or you will need to install large cold air return style grilles in a section of that room's walls so that the humidifier can condition the majority of the basement air.

Basements are a huge source of moisture in a home.

 

What is the humidity level inside your home? It may be uncomfortable to get your home dry enough to prevent condensation on the windows when it's cold outside.

 

First step is to identify any extra sources of moisture. In addition to the shower there are other sources.
Dryer venting inside or drying cloths inside.
Lots of cooking and no fan in kitchen.
Storing firewood inside.
Many people. Humans and their activities generate lots of moisture.

Tell us more about your house, type of insulation or any recent renovations?
It sounds like foam insulation or otherwise super air sealed.

Are the windows old or new?

What climate region are you located? I assume cold, but near the coast?

Bud

 

Condensation in winter if from not enough ventilation. Increase like you have been doing and it will go away. Dehumidifiers should only be used in no load times and summer.

 

I am in Buffalo NY. It is a 1100 sq foot home with 6 people in it. The windows I had replaced a few years ago. There are no exhaust fans in kitchen but I barely cook. No recent renovations other than have the entry doors replaced. The insulation as far as I know hasn't been touched for 20+ years. This condensation happened even with the old original wood windows.

 

Thank you for the added info.
Do you have a gas fireplace? A gas water heater?
Has this been a long term issue or recent? What changed if anything?
Have you checked to be sure the dryer vent is exhausting to the outside?

If you don't have one, pick up a couple of humidity meters that read both temp and RH. They don't have to be expensive and some will have multiple remote sensors. This will put some numbers on the RH levels in different locations. The temp reading is important.

Bud

 

I have a similar problem with condensation on the windows. I have hydronic baseboard heating so there is no air circulation in the winter. The problem is worse in the bedrooms where people are sleeping overnight, but even in an empty bedroom we see some condensation (although less) on the windows. According to my thermostat RH is above 50% this time of year, and still in the high 40s all winter long.

I'll be running a dehumidifier in the hallway this winter and making sure we all keep the bedroom doors slightly ajar to see if this helps. Running it in my basement doesn't seem to help at all, but I think that's because there's no airflow during winter.

I have timers on my bathroom fans and they can be programmed to turn on every hour for a set period of time, so I think I'll try that as well.

 

No fireplaces, gas water heater and furnace are in the same enclosed area in the basement, the water heater vents out the chimney. This has been a long term issue. The dryer is electric and the exhaust I'd vented well to the outside. I have to assume with all the people living in the house, having to do laundry and the 6 showers a day, is what's making matters worse.

 

Quick reply since we are on Golds thread. Do you have curtains on those windows. Curtains block the heat making the windows cooler and increase the chance of condensation. If needed start a new thread and link it to this one. Mods may help.

Bud

 

Actually, I'd double check the windows, are they single, double, or triple paned? Are the seals in good condition?

Condensation on home windows means you have

1) humidity plus 2) a cold surface

What is the temperature of the inside surface of the window? You don't normally think about it, but the glass in a window will generally be at roughly the average temperature between the inside and outside air. Heat actually flows through the window, leading to a temperature gradient across each layer of glass in the window.

So, if it's 70 degrees inside, and 30 degrees outside, a single pane window will be ~50 in the center of the glass, with the inside surface of the glass a little warmer, and the outside surface of the glass a little colder. Double paned windows will be 50 for the air-in-the-center, while the glass inside will be warmer, and the glass outside will be warmer...

For example, my old farmhouse house has newer double pane windows with fake mullions e.g. "dividers" to make the new windows look like 6-over-6 windows.

The dividers actually increase heat flow, so the windows are cooler at the strips where the mullions are, and on cold days stripes of condensation will develop over the mullions.

So, long story short, what is the temperature at the inside surface of the windows?
When there is a sharp change in

 

I also live in the Buffalo, NY area. What temperature do you keep your home temperature at? Confirm you have forced hot air furnace. In most cases you want to add moisture in the winter. You need to find the source of the high humidity. Is the moisture constant through out the day or only at certain times?

 

I keep the thermostat at 69-70 degrees. It is a 25 year old forced air furnace. 1100 sq feet home with 6 people living in it. I notice the windows start to fog up in the evening then by the morning thru out the rest of the day it turns to water droplets and slowly evaporates. I will crack open some of the windows thruout the day if I'm home to help speed up the process. Dont do much of any cooking, but there are a good amount of showers each day which we crack the bathroom window open while in use and keep it open for a while after. There also is an aprilaire humidifier connected to the furnace which I always leave OFF.