Posts Tagged ‘designers’

With so many options, ratings and technologies out there, picking a window can be very confusing. Add to that, you will have your own criteria for look, comfort, energy savings and of course price. However, there are many resources out there that can make this quite easy for you. We’ll list them here:
• Energy efficient windows of any type are going to be more expensive than regular windows. This is something you will need to be prepared for. However, this one-time expense really pays off, and even your remodelling contractor will agree. Energy efficient windows can lead to money savings of 7-24% (acc. To the EPA) and in some climates, upto 40% annually. It is proven that in 2-3 years, energy efficient windows pay off for themselves.
• The kind of windows you will need depends largely on the climate in your region. Your climate impacts your heating and cooling requirements, your house design and your energy bills. In order that your windows provide you with an optimal solution, they need to keep comfortable as high as possible while keeping cost as low. Thankfully, you don’t have to do the math. This neat window selection tool on the efficient window collaborative website gives you how much you can save on different window types depending on where you live. Try it out here: http://www.efficientwindows.org/selection.cfm.
• As obvious, go for windows with the Energy Star rating or the NFRC (National Fenestration Rating Council) logo. Starting 2010, EPA has come up with improved energy star ratings for windows, which can get you tax credit of over $1,500. Make sure you check for a red label marked ‘Qualified until March 31, 2010’ which means the window was made according to the old rating system. The NFRC ratings will give you the values for the five criteria mentioned in our first post in this series and are also very reliable.

Sometimes getting the U-Factor, SHGC and VT values right is not enough. Often, the installation of the window itself, i.e. the entire window assembly can have flaws. These flaws result in air leakage – one of the main obstacles in trying to achieve energy efficiency with the help of windows.
If your house is built on the Passivhaus principles; or you are looking at seriously reducing your HVAC requirements (and thus the bill) then air leakages through windows can punch a large through your plan. Some energy efficient windows specify the AL value (expressed in cubic feet of air passing through for every square foot of the window assembly) between 0-1. The lower the value, the lesser the leakage. The industry-accepted value is 0.30.
Another problem for insulation is condensation. If you live in cold areas, you’ve probably seem frost or dew on the edges of the windows. Looks quite ‘Christmassy’ but it only means that much more heating load. Condensation happens when inside warm air comes into contact with cold panes and glass, which essentially means your windows are not doing such a good job insulating.
With condensation and air leakage, there aren’t fixed ratings to go by. However, certain materials and window technologies work better. For example, if you’re opting for multiple pane windows, looks for stainless steel spacers, or thermally improved spacers made from silicon foam or butyl tape. These spacers might be more expensive, but they are better are insulating, sealing and thus preventing unwanted heat transfer, while at the same time allowing from seasonal expansions and contractions in panes. Similarly, opting for energy efficient windows with two or more panes or glazing reduces condensation even at indoor humidity levels of 45-60%. This is especially true of windows with argon/krypton glass filled windows.

It is very evident that the larger your window, the more natural light it will bring in. Depending on the positioning of your windows, and its visible transmittance (VT) value, your windows could provide you with enough natural light to greatly minimize if not eliminate electric lighting requirements during daytime.
VT values are generally given between 0-1. A rating of over 0.70 is the highest you can get with clear glass windows devoid of any coatings or tints. The more the number of panes, coatings and tints the lower the VT value.
A high Visible Transmittance has another advantage – it eliminates the cooling function which is usually required in a house that uses electric lighting. A high VT value is especially important when a home is built using passive house principles or design.
However, one thing to consider when it comes to VT, is that a window with a high VT value, will also admit that much more solar energy (heat) inside the room. Thus, a clear glass window with a VT of 0.8 will also have an SHGC of over 0.60 – something not at all desirable in a warm or sunny climate.
To get around this, one can use Low E coatings, which are invisible, and yet block heat gain considerably. These coatings also protect indoor furniture and upholstery from the damaging effects of UV rays. Another way is to have operable windows that you can open up to air the room out frequently. Needless to say, a good ventilation system is important when you have large windows and a sunny climate.
For windows that are low on SHGC and high on VT, look for a high Light-to-Solar gain ratio. This determines how much more light is let in without adding to the heat.

There are also quite a few other things you should keep in mind when buying an installing LED lighting. Having the services of an experienced electrician at your disposal is very important, as is the knowledge of an interior designer who’s worked with LED lighting. Bear in mind the following points:
1. White LED lighting tends to emit a specific kind of white light, which is different from other kinds of white light. This causes certain colors to be seen differently. Thus, you might find that your interiors don’t look the way they were supposed upon installing LED lighting. It is thus important to get a ‘test’ done, or seek professional opinion to see if your interiors will go with white LED lighting. (However, newer LEDs seem to have conquered this drawback)
2. Many people will opt for LEDs specifically because of their aesthetic appeal. However knowing where to use which LED lighting is another important factor determining the aesthetics of the entire setup. An array of LED lightings could be used to illuminate an entire room, while miniature LEDs are great for lighting up stairways, corridors and external paths to the house. Many will also use miniature LEDs for lighting up kitchen closets from the inside. Using the wrong LEDs in the wrong place could lead to an interior disaster.
3. LEDs are the most expensive option – only in the beginning. Their initial high price is off-set by their efficiency (and thus the lower bills) and their lifetime. However, using them correctly is important to ensure this happens. Another aspect we suggest to all our customers who look at green building – When it comes to making eco-friendly decisions, we need to look at life time costs, rather than one-time costs. In this regard, LED seems to win the race.

The main reason we’ve included LED in our recommendations, is because they’re quite eco-friendly, compared to all other options. LED produce much more light per watt of electricity. To be precise they produce around 18-22 lumens per watt, much higher than the incandescent and fluorescent lamps. This means they use less power to produce more, which cumulatively adds up to a lot of energy savings. In fact, the US DOE estimates that if LED lighting were used on a large scale, it would convert to savings of $265 billion, reduce electricity demand for lighting purposes by 33% ; and avoid the set up of 40 power plants across the country.
Also, every time you turn on the lights, you’re contributing to CO2 emissions to the tune of 196 pounds per year, for every light bulb in your house. LED lamps bring this to just 63 pounds every year. LED lighting is also non-toxic, it does not contain mercury like fluorescent lamps and thus recycling them is less hazardous. A few other benefits:
• LEDs are extremely small and are available in different colours. This goes well when you try to get creative with lighting in your house.
• LEDs can be dimmed quite easily. Repeated on-off cycles don’t damage LEDs the way they damage other lights. Thus, using LEDs for Christmas lighting is the ideal option
• They’re shock resistant, not fragile like usual bulbs.