2016 Energy Star & Condensation Resistance

Condensation Resistance Now a Critical Rating?

I have always been an advocate of using performance ratings to aid in selecting a good window. If you have spoken to more than one window sales rep, you probably know why. Misinformation, shady tactics, and high pressure are all too common in this industry, and third party certified ratings serve as a way to cut through the salesmanship and compare replacement windows objectively. Unfortunately for you the consumer, things just got more confusing in that area.

Enter Energy Star Version 6

Much like U-Factor and solar heat gain, condensation resistance is a rating certified by the NFRC. In the past, this rating has moved nearly linearly with U factor in most cases, as it generally improves as the thermal performance of a window improves.

Whether you are aware or not, there are some MAJOR changes taking place in this area, and it has to do with the new 2016 Energy Star requirements for the Northern Zone, which call for a .27 U-Factor.  To clarify, this rating only applies to the Northern Zone.

Other zones still use ratings that are more easily achieved, and still effective for those areas. On the plus side, .27  is a darn good U-Factor for double pane glass, and for the most part, to this point, only good to excellent windows have achieved that rating.  The problem of course, is that there are A LOT of middling to poor performing windows on the market that could not hit that number.  That is of course without utilizing glass technology that has side effects.

The standby in this area is a heavy coat (or more than one) of low-e, often 366 glass or comparable. This results in a pretty dark window that cuts a bit too much solar gain for many homes in colder climates.  The newest, and potentially more harmful option is a surface 4 low-e coating. This is a coating of low-e that is applied directly to the surface of glass that you can touch from the interior of your home. You might think that this would be cause for concern with scratching and durability, however, these concerns are largely unfounded. The larger issue is how this rating affects condensation resistance, particularly since the region of the country in question struggles with window condensation issues as is.

alside fusion ratings and reviews
For example, here are the ratings for the lower end Alside Fusion window with the typical Climatech Glass. Notice the U-Factor does not meet the Energy Star guidelines for the Northern Region, but the condensation resistance is 56 which is decent.
condensation on Alside window
Here are the ratings for the same window with the Climatech SF glass option. This lowers the U-Factor to meet the Northern Region requirements, but look at what it did to the condensation resistance. This window is MUCH more likely to develop condensation when it gets cold outside.

To very simply describe what low coatings do, they reflect heat. By placing this coating on the interior surface, you effectively keep that pane of glass and the airspace behind it from warming. Colder glass= MORE CONDENSATION when all other conditions are equal.  The condensation rating drops precipitously, by nearly 10 points in many cases.  Ratings in the upper 50’s and 60’s are dropping down into the 40’s in some products with the surface 4 low e coating.  While there are ways to mitigate the amount of moisture in your home to compensate, many homes in the Northern region have enough of a challenge doing that without injecting this additional difficulty into the equation.

What is the Solution?

Well, there are a few things that you can do actually. One, buy a double pane window that achieves a .27 or better without this coating. Incidentally, if you combine this with a good air leakage rating under .05 or so, you can be assured of getting a pretty darn good window. Two, buy triple pane glass, which in the Northern region should be given strong consideration anyway.  Three, forego buying an Energy Star rated window in favor of one that will actually be better suited to your needs and budget. Personally I’d opt for option one or two, however, option three is better than unknowingly installing windows that may end up looking like a shower door in your home. This issue is particularly important for wood interior windows, as interior condensation is one of the leading causes of damage that I see to wood windows installed in the last 30 years.

condensation resistance
It may be a little hard to tell from the picture, but this window has condensation on the inside of the house on a cold day. If you touch this glass you’ll get all wet.

Location is Key

One final thing to clarify, is that both the Energy Star rating in question, as well as the gravity of condensation as an issue are fairly unique to the Northern Zone and colder climates. This coating is not inappropriate in other regions, and in fact, is excellent technology when applied correctly.

In addition, it should be noted that Energy Star HAS proposed an equivalent certification where a lesser U-Factor can still qualify provided that the difference is made up by a higher SHGC. Unfortunately, those trade-offs are still somewhat challenging to achieve, and nobody wants to advertise a less efficient U-Factor since that is the number one rating that consumers use to compare.

Ultimately, the moral of the story is buyer beware. Do your homework when making a purchase of this magnitude. On the plus side, you are HERE, so that’s a great start!

Brandon Erdmann is the owner of HomeSealed Exteriors in Milwaukee, WI.  He’s a window installation expert, a supporter of this site and an all around great guy.  If you’re in the Milwaukee area and you’re thinking about new windows you should give Brandon a ring.  You’ll be glad you did.

Why do I get moisture on my windows?

Why do I get moisture on my windows? 

When it comes to new windows, this is a very common question.  It is also a very common phenomenon.  In fact, most manufacturers have great information on their websites about condensation (moisture), what causes it, and how to prevent it.  If you have moisture on your new windows, don’t worry!  Even the best windows out there will get condensation on them if certain environmental conditions allow for it.

condensation or moisture on windows
Here you can see condensation on the inside of new replacement windows.

Usually a person’s first fear when seeing condensation is that something is wrong with their beautiful new windows.  Although the moisture may be ugly, it might actually be a sign of a good thing – a proper seal.  Since there are a lot of factors that go in to why condensation occurs, the important thing is to be open and understanding that the moisture may be a consequence of something other than the new window.

Here are the main factors that contribute to condensation on a window:

  • Exterior temperature
  • Interior temperature
  • Interior humidity levels
  • Interior ventilation

 Minimizing Condensation

I’ve never been great at physics or science in general, so I will not get in to the reasons that cause condensation other than mentioning the conditions that must be present to cause it – humidity and contrasting temperatures.  If your windows are getting condensation on them and you’d like to stop it or minimize it, here are some tips:

  • Open your blinds/curtains.  Trapping moisture in an area that is colder will certainly lead to condensation.  Keeping blinds and curtains closed will prevent air flow.  Of course, privacy might be more important than a little water on your windows so I understand if this isn’t a viable option.  The sacrifice will be to wipe down those windows daily, at least for part of the year.
  • Run a fan.  This is important especially in bathrooms and kitchens.  Whenever you’re cooking or showering moisture is evaporating in to the air.  Keeping good air flow during and after these activities will keep that moist air from moving toward the windows and condensing.
  • Adjust humidity levels as seasons change.  Most whole house humidifiers have a setting that can be adjusted.  If you don’t use a whole house humidifier but run a different type, it might make sense to buy a hydrometer.  They cost about $11.00.  As a quick guide, humidity levels in the winter should be about 25%-30% with indoor temperatures between 65 and 70 degrees and 25%-60% in the summer with indoor temperatures between 72 and 80 degrees.
  • Open your windows.  Sure, when it’s 7 degrees outside you might not want to do that (although it will help), but when it’s nicer outside or when you’re showering, cracking the window a little will help with air flow and will let moisture move toward the colder outside air.
  • If your house is very “air tight” and if you have a forced air furnace, it might be good to look in to installing an air-to-air heat exchanger.  This will help properly ventilate your home.  Of course, an HVAC expert would be more helpful than I would in that category.

The list above will help with some common condensation questions.  Over the years I’ve seen some oddballs too.  Below is a great picture of what happens when a furnace vent is pointed at a window.  To solve this, a deflector that routes air in to the middle of the room solved the problem.

condensation on picture window
You can see the effect of the vent being pointed at the window.

Another much less common condensation issue has to do with moisture on the outside of the window.  I’ve only ever seen this when 4 conditions apply – it is summer, outside temperatures drastically warm up overnight, a water source (like a pond) is nearby, and A/C is running.

condensation or moisture on patio door.
Here you can see condensation that has formed on the outside of a sliding patio door.

This makes it very difficult to enjoy a beautiful morning, but don’t worry, the sun will rise and the moisture will evaporate away.  To not have this happen, I imaging turning off the A/C would have been the solution.

Sam Steinacker is one of the owners of Window Universe in Cleveland.  Sam has many years of experience in the window industry working in manufacturing, distribution and sales.  He knows windows inside and out.  If you’re anywhere in Northeast Ohio you should give Window Universe a ring.  

How to Repair Foggy Windows – It’s pretty easy!

One of the most common calls we get in the office is from folks looking to repair foggy windows.  I think we’ve all seen what this looks like, but just in case, here’s a picture of the window dog himself  trying to look for intruders through a foggy double pane window.  It’s not easy to see the bad guys coming!

fix a window seal failure
The little fella works so hard to keep us safe. The least we can do is provide him with a clear view!

This happens when the seal fails allowing outside air into the glass unit.  That air brings moisture with it and instantly you’ll see condensation or a film on the glass.  This is ugly and it’ll never go away by itself.

Luckily for you we’ve made a quick video demonstrating how we fixed this problem.  Enjoy!

It is important to note that even after your window is repaired it’s still an old window.  You may find that replacing the window doesn’t cost much more than the repair and in that scenario you’d get a whole new window.

In this case, this is a wood 3-lite casement window with a clad exterior.  The cost to replace this window would likely be over $2,000 so a repair makes sense and the results were fantastic.

fixed glass in replacement window
Now thats better. Frisco has a much better view and those pesky deer don’t stand a chance!

Now we’re still having some trouble with this window.  The old cranks are a little shaky and it just doesn’t operate as well as a shiny new window would.  It’ll probably get replaced sooner or later, but this repair will give it several more years of life and the whole room looks much better.

If you’re thinking about repairing your existing windows it certainly is possible although not always as easy as it looks.  Replacing a sealed insulated glass unit in a vinyl replacement window can be tricky because the vinyl trim pieces can be brittle and if they break you may have a very hard time finding a replacement.  We’ll have another video coming out soon on repairing or replacing glass in a vinyl replacement window.

Why am I having a hard time finding a company to do this?

Because it’s a bit of a hassle for the amount of money folks will pay.  A professional may have a tool to measure the glass without removing it, but still you’re talking about 2 trips to the house, a few hours of work and taking the risk that something breaks or some unexpected problem arises.  Factor in the driving time, the ordering, picking up the glass and this quickly turns to a project that requires many hours of work.

If you’re looking to pay $50 for someone to do this you’re going to have a real hard time.  It’ll probably cost several hundred dollars to hire a professional, but if you’re comfortable tackling it yourself you could get it done for much less.