Tuesday, December 2, 2008
Kudos To The Energy Star Program
Right now it's hard to find a window that doesn't have the Energy Star sticker on it. In Zone 5, where I happen to live, there are windows on the market that are 2 and 3 times more energy efficient than other windows. The public should reasonably expect that one would have a higher ranking than the other. If you understand the NFRC label there is a huge difference. If you look for the Energy Star label it's virtually worthless.
U-factor, from the NFRC label is very meaningful to those of us in the north. It is the measure of heat transfer or loss. When temperatures can hit 30 degrees below zero it matters. You want to know what you're getting. If the average consumer looks at the Energy Star label on a window they believe it is an energy efficient window. Guess what? It might be better than what you have but it might not be that big of an upgrade in terms of energy efficiency.
Starting in 2009 the u-factor has to be .30 to .32 (the lower the better). There are already a few windows on the market with a u-factor rating of .16 to .20. In 2015 the standard lowers to .20 for a minimum.
The DOE is making the Energy Star label making mean something in the future. One of the windows on the market today offers a 33% fuel saving pledge. Their u-factor gets as low as .16 while Energy Star labels it the same as windows that are less than half as energy efficient. With the new Energy Star Standards maybe the general public won't need a 33% fuel savings pledge to see who really has an energy efficient window.
I know they had good intentions from the beginning. Separating the men from the boys will make the Energy Star logo mean something on windows. They are consciously making an effort to reduce the number of windows that meet their standards to less than 25% of the windows on the market. Kudos to the DOE.
Free Press Release
Sunday, November 30, 2008
Replacement Windows Take Planning
One of the first things I recommend doing is to inspect your windows from the outside. Take note of the wood and siding around the window unit because it is as important as your window choice in the long run. If you find rotting and/or holes and cracks around the window you probably should be doing a full frame window replacement.
A full frame window replacement is one that includes complete removal and replacement of the whole window including jambs, casing, head, sill, and sash. In most homes there has been water leakage over the years that has caused rotting and, possibly, mold. When the contractor removes the old window unit they have clear access to inspect and replace any problems they find. They can also re-insulate immediately around the replacement window unit for better overall performance.
Decide what material you want. There are three basic materials used in the replacement window industry. Those three materials are wood, vinyl, and aluminum.
There is no wood window on the market with a lifetime warranty. The basic problem is that wood rots. They just can't count on it to last. It also doesn't have the insulating value of vinyl and aluminum because both of those can be filled with some type of insulation like foam. Condensation is inevitable, especially when your house is well insulated. The condensation drips down the inside of the glass and causes the water to collect on the wood sash. Wood gives you maintenance headaches and premature death of your windows.
In cooler climates aluminum windows are not a good choice either. Aluminum conducts heat and cold so they don't offer the insulation value of the same window built with vinyl.
I always recommend vinyl replacement windows. Within the classification of "vinyl replacement windows" there are high quality vinyl and low quality vinyl components used in a variety of windows. Make sure that your are only considering virgin vinyl. Recycled vinyl is not good in replacement windows and is really not a green product. Using reground vinyl creates instability within the vinyl because the polymers are trying to get back to their original shape. In the sun the various reground vinyls will crack or break during expansion and contraction.
And now we've reached the biggest item for you to consider. Glass is the single most important factor in choosing your replacement windows. 85% of the window unit is glass and glass is the easiest thing to get objective rankings for. The NFRC provides the data you need in their rating system. As you will see, there are thousands of window manufacturers that have their products rated by the NFRC (National Fenestration Rating Council). Understanding the data makes it simple to know which windows are the contenders and which ones are the pretenders but understanding the NFRC label is the easiest way for you to rank the various windows.
Surprisingly, the big three, Andersen, Marvin, and Pella don't seem to come close to some of the smaller companies in their standard offering. There are many really good ones but from what I've seen the two best overall replacement vinyl windows are Preservation Windows and Gorrell Windows. Using the criteria I talked about will help you decide which window works for you. What I think doesn't really matter, what do you think?
U-Factor More Important Than R-Factor For Windows and Doors
Radiant Heat Transfer
Radiant heat transfer is heat flow via absorption and then re-radiation. (An easy example is when you put your arm into the direct summer sun and it starts to warm up.)
The NFRC gives each window a U-factor rating. The U-factor is the inverse of the more familiar R-factor used in attic insulation. So a U-factor of .5 equals an R-factor of 2. The lower the U-factor the better.
When comparing windows, check for the NFRC label. Look for the U-factor. The first number after the words "U-factor" is the rating that's appropriate for residential purposes. It will be marked "AA" or "Residential." The U-factor marked "BB" or "Non-Residential" is for commercial window applications. Use the U-factor rating to make meaningful comparisons. Be wary of a window vendor who won't provide this number.
How far should you go? Obviously, you need to get price comparisons to make a decision. Keep in mind that a good portion of your cost is installation, so it makes sense to leverage those costs by installing a better window.
Convection Heat Transfer
Convection is the transmission of heat caused by movement of molecules from cool regions to warmer regions of lower density. The word "convection" is derived from the latin term convehere (to bring together).
Convection heat transfer is heat flow via air movement. (An easy example is when you turn on a hair dryer and the hot air is projected from the end of the hair dryer.)
Conduction Heat Transfer
Conduction is heat transfer through materials. (An easy example of conduction is when the handle of a pot on the stove gets warm. The heat is being conducted from the bottom of the pot all the way to the handle.)
An energy efficient window designed for heating-dominated climates minimizes heat loss by controlling all three sources of heat (energy) transfer.
Creating Energy Efficient Windows For Cold Climates Like Minnesota
The window industry uses the term u-value to measure heat flow. (A lower u-value means better thermal performance.)There are a number of glass-related options that window manufacturers can use to design energy-efficient windows in cold climates. Most of these techniques improve the thermal performance of the glass. A brief explanation of each follows:
- Insulating Glass
Insulating glass is comprised of two (or more) pieces of glass separated by a spacer material and sealed together to create an insulating glass unit (IG unit). IG units reduce convection and conduction heat loss. - Low-E Glass
Low-E glass has an almost invisible, microscopically thin coating that reflects long-wave infrared energy (or heat). When interior heat energy tries to escape to the colder outside, the Low-E coating reflects the heat back to the inside. The Low-E coating reduces radiant heat loss through the glass. - "Warm-Edge" Spacer System
The spacer material separating the two glass panes can be a source of conductive heat loss in cold climates. The thermal performance of IG units can be enhanced by using the SST spacer material that has a lower energy conductance rate and/or has less physical mass which equates to a lower energy transfer path.
Northland Home Exteriors - Dealer of Distinction
When you choose Preservation, you not only get the industry's best windows and siding, you get the best dealer. Northland Home Exteriors is the Twin Cities area Dealer of Distinction for Preservation Premium Windows and Siding. Every Dealer of Distinction is sure to posess all of these attributes:
- High quality installation and service standards
- Design Expertise
- Established, Consistent Reliability
- Results-Oriented Consulting for Energy Solutions
- Solid Reputation in the Community and Industry
- High Rate of Customer Referrals
As the newest member of the Preservation Dealer of Distinction Program Northland meets all of these qualifications. They have a proven track record and their owner, Doyle Land, has more than 20 years experience in the business. He knows a great product when he sees it, making Preservation and Northland partners with the same goal.
A Dealer of Distinction is a dealer of impecable credentials. When you choose Preservation Windows and Siding you not only get the industry's best windows and siding you get the best dealer along with it.
Preservation isn't ordinary windows and siding. Intensive research and development give you unsurpassed beauty and uncompromising quality. It only makes sense that you can only get Preservation products from dealers who meet the same standards. There are only 22 Dealers of Distinction nationwide and we think that they, and our products, will be a perfect fit for your home.