I have reli-built windows from a local home center.They are only 2 years old and were installed correctly.Its 29 degrees this morning here in west virginia,and my windows have moisture all over them.Its similar to a car window after the defrosters have been on.Ive checked the seels and they seem fine,and we are not running the furnace.The temp was mid 60's yesterday,dropped overnight,and will be in the 60's again today.Is this anything to worry about?BY the way,the moisture is on the inside.
Re: Window water
It's unknown as to the construction of the windows you refer to ... for example dual or triple pane with argon gas , etc.. The manufactures of windows have made advancements toward increasing the efficiency performance they still are one of the coldest surfaces relatively speaking.
You mentioned the furnace is not on so the stagnant warm moist interior air contacts the cooler surface of the window there can be condensation that occurs. This can be more of an issue depending on the humidity level inside the home from things like cooking , showers etc. that build up inside since the doors and windows are closed during the cooler temperatures... trapping this increase of moisture. Sometimes just by running the fan on the furnace will circulate the air within the home and having the movement of the air will help with preventing this.
The installation of the windows can be another factor depending on how the gaps between the window frames and the structure was sealed. If they had simply stuffed fiberglass in the gaps you may be having air infiltration coming in from the moldings around the windows. If this occurs the cool outside air will contact the warm moist inside creating condensation. Usually using spray foam in the gaps will seal out air infiltration.
If there were any insulation and sealing as well as a high efficiency furnace upgrades done to the home recently this will contribute to an increase in humidity levels since the home is not as leaky and breathed as it once did. Things like running bathroom and kitchen exhaust fans longer may help with regulating the humidity inside the home. Another possibility is the need for a Heat Recovery Ventilator ( HRV) which exchanges inside stagnant air with fresh outside air allowing the house to breath in a controlled manner.
Hopefully this helps.
Re: Window water
The relative humidity inside your house is currently higher than the cold surface of the windows can tolerate without some of that moisture condensing on the glass.
Windows are usually the first place that you'll see this condensation because the glass is usually the coldest surface of your home's exterior surfaces. Today's double-glazed windows can only achieve about R-4.5 The walls are likely insulated to a much higher R-value and so won't condense at the same time because they are warmer.
In order to rid yourself of this condensation you must either raise the temperature of the glass or lower the RH inside the house.
If you have forced-air heat, it will likely consume some of this excess airborne moisture over time, but that alone may not be enough. You also have to prevent the introduction of more moisture by using exhaust fans over the stove and in the bathrooms, etc.
If you have FA heat and there is a humdifier installed, you need to make sure it isn't set too high and contributing to the introduction of more moisture at a time when it's already too high.
If you have curtains, d****s or blinds over these windows.....those will/can interfere with the movement of warming air over the glass. This means they'll contribute to the formation of condensation on the glass.
You may have to run a dehumidifier for a while to get the RH down and under control.
Re: Window water
Thanks for the info guys,i did a lot of upgrades to insulation and structure sealing this summer.I didn,t think i would see results this soon.I used good windows with all the energy saving features.I did a lot of cooking yesterday for my favorite time of the week,watching the Steelers kick butt!Thanks again for your help.