The window numbers game.

“How do you choose a good replacement window? What is the difference between the $200 vinyl window and the $500 vinyl window? They both look the same, right???”… These are some of the most common questions I hear from folks who are shopping for windows. One common answer is that “The truth is in the numbers,” as in the NFRC and/or AAMA performance numbers. This statement is true, however it is not comprehensive. The fact is, you can only find the truth in the numbers if you fully understand what they mean, so here is a quick rundown:
-U-value: The U-value, or U-factor is probably the single most important number to look at in a window, as it states the thermal performance. As the U-value gets lower numerically, the thermal efficiency increases. It can be difficult to determine the quality of a window however based on the u-value, as inferior products do offer glass packages with decent u-values, and high quality products also offer several glass choices. Be sure when comparing u-values that each window’s number is for the “total unit”, including glass and frame as this is the “true” u-value as determined by the NFRC. Some companies use “center of glass” or COG ratings which typically run much lower. This practice is typically used with the intention to mislead consumers.
-R-value: The R-value or R-factor is just another way to classify the thermal performance of a window. To convert U-value to R-value, you would take 1/u-value. So a u-value of .30 = an R value of 3.333. Generally u-value is preferred when measuring the performance of a window. Once again, the practice of using R-values is often confusing and misleading, many times using the “center of glass” value mentioned above.
-SHGC, or Solar Heat Gain Coefficient is essentially a measurement of the amount of solar heat that is allowed to pass through the window. The climate in which you live will determine the ideal level of shgc that you will want. Generally shgc ranges from the .1X’s to the .3X’s. Homes in hot sunny climates want a lower number, while homes in colder areas still want to take advantage of some of that passive solar heat in the heating months, so a little bit higher number is better. Typically the shgc is somewhat of a balancing act with u-value, as to what will provide the best overall energy efficiency.
-CR is Condensation Resistance. This measurement reflects how well the window replacement will resist condensation. Generally a window with better thermal efficiency will have a better CR rating, however the design of the unit as well as how tightly it seals will have an effect as well.
-VT is Visible Transmittance. This measures how much light is allowed to pass through the window. Some homes that don’t see much sunlight or have abnormally small window openings may be more concerned with this rating, however it generally is not given much weight in the selection.
-DP is Design Pressure. This is a structural test administered to measure the overall strength of the window assembly and it’s ability to stand up to wind forces. For this purpose, it does not have much bearing on most consumers who do not live in hurricane zones, however the DP rating can give some idea as to how well the window is constructed, and how it will stand up over years of service. Most vinyl windows have a DP rating of 30-35, however many models that are reinforced with fiberglass, aluminum, or some other material will have ratings from DP 45 – DP 65 or even 70. A DP 50 is generally considered quite good, and demonstrates a well designed and constructed product. It is worth mentioning that non-metallic (fiberglass and other variants) reinforcements are considered to be superior to aluminum or steel due to their less conductive properties.
-AI/AL is Air Infiltration/Air Leakage– the terms are interchangeable. This rating tells you how much air will pass through the entire unit. Most people are replacing windows primarily do to them leaking air, so the AI rating is certainly worth consideration. The AAMA gold label standard is set at .30, however, there are products on the market that go as low as .01 in a double hung, and even better in a casement.
…. So there it is. This list is not 100% comprehensive, however it is certainly the nuts and bolts of what each rating means, and how it effects you as a consumer. It should give you enough knowledge to find “truth in the numbers”. Some other intangible but very important aspects of your window replacement decision are reputation of the company/manufacturer, and record of quality control and customer service. It can take a little effort to get a good feel for a product in this regard, however there are many online sources such as blogs and forums where consumers and professionals alike give objective (hopefully) feedback based on their own experience.

Window condensation

“What is the deal with window condensation?” This is a question that I hear pretty frequently especially in the colder months. Unfortunately, I even hear it sometimes after a client has already gotten replacement windows. Basically, window condensation occurs when warm, moist air on the inside of your home cools and contracts and its moisture condenses. Most of the time this will happen on the coldest surface in your home which often is the glass of your windows. “Does this mean my windows are bad?” No, most of the time it does not mean that. By getting replacement windows you will have a warmer temperture on that interior glass surface, therefore reducing the likelihood of condensation, however if your home is damp enough, even the best windows in the world can develop condensation. This could be a sign of a moisture problem in your home. Sources of moisture are people, pets, plants, cooking, etc. Problematic sources of moisture could be basement issues, as well as improper ventilation in the attic or other areas. Getting your home completely sealed with new windows, insulation, etc. came sometimes make these problems appear worse as moisture used to be able to escape through those same areas.
“What can be done to address this?” There are a few things that you can do to regulate the level of moisture in your home. 1: Increase ventilation. Make sure attic vents are open and clear, make sure all exhaust fans from kitchens and bathrooms are properly ventilated out of the house (not just into the attic). 2: Monitor the humidity level in your home with a humidistat or humidity monitor. If necessary, run a dehumidifier in the basement to keep the indoor humidity level around 30-35% or less in winter. A few other small things would be to group plants in one room and avoid over-watering, and also keep window treatments open when possible to allow warm air to circulate across the glass and keep its temperture up as high as possible.

Energy saving tips

Now that we are in the middle of winter, it becomes a bit easier to tell where you home’s heat retention shortcomings reside. Maybe your walls are cold, your basement is freezing, or you can feel (or even see) a cold draft coming in around your doors and windows. Obviously it would be ideal to get replacement windows, doors, or insulation, but sometimes it just isn’t in the budget. Here are a few tips to save you some money, and add some comfort in your home for a low-cost.
As mentioned in previous posts, windows and doors can be a huge source of heat loss. There are a few things you can do to improve this short of window replacement. First, is the good-old window plastic. It is ugly, inconvenient, and a pain to apply, however it really does work when properly installed. A slightly more visually appealling option altough it doesn’t work quite as well, would be “seal and peel” caulking. This is a type a clear caulk that you can apply to areas of the windows that experience air-infiltration. It will semi-harden, and be ready to peel off in spring just like the plastic would be. One thing to keep in mind with either of these methods however, is that they can pull paint or finish off when removed.
On doors, you can actually do a more effective, somewhat permanent fix by replacing (or adding) weather stripping around the opening, as well as the threshold. You should be able to pick up the proper products to seal up one door for around $10-$20 from any hardware or home store.

Window materials and options

When shopping for replacement windows today, there are a lot of different options in terms of materials and grades. The biggest problem with this is that everybody says that what ever they are selling is the best and everything else is junk. I’ve already talked a little bit about cutting through the bull and finding out about window quality, but what about material? The main choices available these days are vinyl and wood, with fiberglass and other composites forming sort of a niche market. The fact is, there is no single replacement window material that does not have some pro’s and con’s. Here is my very brief, and very general breakdown. First, assess your reason for purchasing new windows. Is it energy-savings, aesthetics, funtionality? Secondly, assess your budget. You will likely need to sacrifice something, especially if like most people you do not have unlimited funds.
The most affordable product line available is going to be vinyl windows. Vinyl windows have a very wide range of quality and options and should run anywhere from $225-$800 per unit (including installation) depending on grade and options. The main benefits of vinyl windows would be value. Vinyl windows will, without question give you the best “bang for the buck”. They will have the highest energy-efficiency (lowest u-value), the best warranty(usually lifetime), and cost less than wood or fiberglass. There can be a lot of drawbacks with poor quality vinyl windows such as warping, fading, seal failures, etc., however the higher-end, energy efficient vinyl windows that are available today have cured these issues with the use of higher quality materials and stricter standards.
The benefits of a wood product (and drawbacks of a vinyl product) would be the initial structural strength of the product, and the beauty of a real wood window. Vinyl windows have laminite wood-grains interiors available for the look of wood, however the truth is that there really is nothing as beautiful as a real wood window that can be stained to match your existing woodwork. Extruded aluminum exteriors have made wood windows a “low maintenance” option on the outside, however the interior will always need attention or risk rot. Wood windows usually start out around $500-$600 installed although a quality unit will run higher. A general rule of thumb is that a full-frame wood window will typically cost about twice as much as a vinyl replacement window. Wood windows can be very energy-efficient, however it is typically more difficult for them to achieve the low u-values available with a vinyl product. One thing to keep in mind is that some subdivisions and homeowner’s associations have requirements such as “all-natural materials” that can affect your decision.
Fiberglass and composite windows are fairly new to the market and do have some merit, however they are typically WAAAY overpriced. They have decent attributes when it comes to energy-efficiency and strength, however they really don’t deliver anything that you could not get in a high quality vinyl or even wood window, and they are typically the most expensive option.
The bottom line when it comes to choosing energy efficient windows, is that you really need to assess your own priorities and pick a product that fits your budget and your home, and as always, do some homework. There are thousands of people who have already made this purchase and have listed their opinions on blogs, etc. Good Luck!

How to choose the right window contractor

The most common advice I hear people give about choosing a window contractor (or purchasing anything for that matter) is “Just don’t pick the lowest bid or the highest bid”. The truth is, if you follow that advice strictly you might just miss out on the best value. I’ve given proposals to clients where I’ve been the cheapest, and others where I’ve been the most expensive. The funny thing about that is my prices weren’t any different between those bids. It just so happens that the competition I was against were on completely different ends of the spectrum when it comes to window contractors. Here is my honest advice on how to choose a window contractor: First, make sure that you are comparing apples to apples on the product. This can be easier said then done because on one hand there is definitely a wide range in quality and price of the products available, but on the other hand, there is also a wide range in price that companies charge for a window that is the same or comparable. (See my previous post “Straight talk on windows” to help decipher this.) After you’ve narrowed your choices down to contractors who have presented a quality product that fits your needs, next comes the really important part: Picking a contractor who will install that window correctly and stand behind it with a good labor warranty. Things to look for are certifications, membership in trade organizations such as NARI and BBB, and ask for names and contact info of previous customers. This information can be like gold. You can physically go to a completed jobsite and see a finished product as well as find out what type of experience other customers have had. Another thing to do is just plain ask how they install their windows. The person presenting to you should be able to go through a detailed description of how they install a window and why they do what they do… If you have done all of these things and are still left with more than one choice, it is now time to take a hard look at the price differences and balance that with smaller things that may push you one way or the other. These could be issues such as a local family company versus a nationwide corporation, how easily you’ve been able to get your questions answered, or just having a better feeling about one company than the others.
I feel confident that if you follow these steps, you will make a choice that you will be happy with for years to come.