Wenatchee Home Inspections

A common issue with older home is drafty windows and condensation. When you have a cold surface such as we have in winter will cause the moisture in the air to reach its dew point then condensate on the window.  

                                                                       

I know we all have sat down on a hot summer day with a glass or bottle of cold beverage. After a few moments the outside of the glass or bottle begins to sweat. What is happening is the water vapor in the air, even the extremely low humidity air we typically see here in the Wenatchee area, contacts the cool surface of the glass or bottle the molecules of he water vapor slow down and get closer together eventually turning that gaseous water vapor back into water which is not water droplets on your glass or bottle. The surface of the cold glass has now reached its dew point.

                                                                                       
Dew point definition-
“The temperature at which the water vapor contained in a volume of air at a given atmospheric pressure reaches saturation and condenses to form dew. The dew point varies depending on how much water vapor the air contains, with humid air having a higher dew point than dry air.”

So now back to our windows, much like a glass of ice water on hot summer day our windows are now so cold that they will create a dew point on their surface and cause the water vapor in the room to condensate. This can lead to staining and potential mold growth on the windows.
Aluminum windows will be much worse due to the fact that metal is a much better conductor of heat and cold than wood or vinyl.

Keeping the humidity down in the home will help but it most likely will not completely stop condensation from happening.

So what do we do? Obviously replacing the windows will help and may be the best option but this will be the most expensive. But another way to help is to introduce another surface between the window and the condition room, much like a thermal double pane window.

We have all seen plastic films put on the windows and they will help. Another interesting solution is a produce such as a window insert. Now they will be cheaper than a window replacement but they are not necessarily cheap, such as Inwindow coming in at around $24 per SF for standard grade or $36 per SF for any of the premium grades.  

As example a Standard Windows Size – 44″ x 44″ in size dimensions or 3’8″ x 3’8″ will run about $325.

Inserts seem to be ideal if you are looking to keep the old windows for  appearance. These inserts will not change the visual appearance on the exterior of your home.

There is some other things these inserts may provide, noise reduction which may help with a decision.

From a study in Oregon-

“Conclusion:
Laboratory tests demonstrate that the Indow Window product can reduce noise penetration into a space by 10 to 20 db. Adding Indow Windows to a standard single pane window can also result in an improvement of the thermal performance of the window approaching that of a standard double pane window.

Modeling of the performance of Indow Windows in typical older vintage homes with single pane windows suggested the potential to save on the order of 10% in natural gas consumption. Actual measured performance averaged across 4 pilot homes indicated a savings of 19%. This discrepancy is likely due to the additional thermal benefits resulting from the warmer interior surface of the Indow product which would result in improved thermal comfort at lower room air temperatures.”

Study link-
“https://indowwindows.com/wp-content/uploads/2013/04/Indow_report_March_2013_FINAL.pdf”



Here are several companies  that do inserts

https://indowwindows.com/

https://www.windowinserts.com/

http://www.climateseal.com/thermal_window_inserts/thermal_windows.htm

https://www.energyvanguard.com/blog/winterizing-your-home-dont-caulk-the-windows

https://www.energyvanguard.com/blog/10-uncommon-tips-winterizing-your-home


Winter is coming and you should be looking at your home and ways to gain better energy efficiency and air leakage not only for cost saving but for comfort and moisture control.

“It is one of the blessings of old friends that you can afford to be stupid with them.”

Ralph Waldo Emerson

If you find any errors or have additional information that would expand on any code, building standards or manufacturer requirements please let me know.

NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…  

Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service

Instructor- Fundamentals of Home Inspection-  Bellingham Technical College

WA Home Inspector Advisory Licensing Board

www.ncwhomeinspections.com                                                   509-670-9572

You can follow me on Facebook, Twitter, Google+ and on my website Blog.