Summer Energy Efficient Windows  — Part 8

It’s summer now here in South Texas. Those energy efficient windows are calling my name!

The solar energy coming our way brings heat and lots of it. The aim of energy efficient windows is to keep that solar thermal energy at bay!the cost may be prohibitive, even with energy tax incentives attached.

For those who grapple with fixed incomes and rigid budgets, it still comes down to basic economic factors. Replacing windows solely for saving the energy bill is not often a cost-effective measure. See replacing windows at the Energy Star site.

So if the economic factor is your prime motivator, you can make your existing windows more efficient by using a few other methods:

·    Cellular shades

·    Curtain panels with interlinings

·    Window films

·    Solar screens

·    Cover your windows during the sunniest times of day

But if you need to replace your windows for other reasons, maintenance perhaps, or you just want nicer windows, make it an occasion to provide your home for comfort and energy cost savings.

Summer Energy Efficient Windows – Part 6

Window choices get complicated:
·    U-factor
·    Solar heat gain coefficient
·    Visible transmittance
·    Air leakage
·    Condensation resistance

Then there’s the climate issue! Homes in the Northeast need different windows than homes in the desert Southwest.

Trying to do your best at efficiency and economy could easily seem to require another college degree!

Could someone just TELL me which window I need?

Glad you asked.

The Department of Energy and the United States Environmental Protection Agency do all the testing and analyzing and rate windows according to their effectiveness.

The simplified version of window data analysis is found in an Energy Start label.

An Energy Star labeled window receives high marks for u-factor and solar heat gain coefficient.

And to find the best window for your climate check out energystar.gov.

Summer Energy Efficient Windows – Part 5

There’s a huge learning curve to energy efficient window expertise.

Not that one requires “expertise” in window manufacturing to purchase the best windows. However, you do need a certain knowledge base in order to get the right window for your particular needs.

You can’t just go to a window store and pick a pretty window any more than you go to the shoe store, and simply pick out a pretty shoe.

Windows, like shoes, must be matched to the wearer.

The search for the best energy efficient window is still on.

“Condensation resistance” is another feature to look for while you are reading those window labels.

Condensation resistance measures a window’s ability to resist condensation or water buildup; the higher the number between 0 and 100, the better. Higher numbers indicate a product’s ability to resist condensation.

Note: Rating a window for condensation resistance is optional; window manufacturers can choose not to include this rating in on their labels.

Summer Energy Efficient Windows – Part3

In the final months or my energy conservation mode, I’m beginning to gear up for the next step – Energy Efficiency. My study now revolves around windows for summer energy efficiency.

Today’s window performance rating element is visible transmittance (VT).

Visible transmittance tells you the amount of light a window allows though. Efficient windows are energy savers and will reduce my energy bill, but I still need the daylight shining into my house to keep my inside plants alive and to keep my sanity!

The visible transmittance (VT) is measured on a scale of 0 to 1. Usual values are between 0.3 and 0.8.

The higher the visible transmittance (VT) rating on the window, the more light passes inside. So for the greatest amount of daylight and to enjoy the view from your windows, the visible transmittance (VT) rating the better.

But there is a trade-off. You see, lower the VT number, the better a window insulates. To get maximum daylight transmitted inside, I lose insulating capacity.

Hmmm…I’ll have to think about this more. Perhaps some of my windows need more insulting that others.

Summer Energy Efficient Windows – Part 2

I love windows.

They allow light into an otherwise dark spaces. They provide restful views of the green outdoors when work requires you to be indoors. They allow clean air to circulate and freshen up your living spaces.

On the other hand, windows usher summer heat inside to compete with your air conditioning.

So if you are in the market for more energy efficient widows it’s time to do some homework.

Last time I posted about the U-factor.

Next, check the solar heat gain coefficient. This number measures how well windows block heat from the sun. The coefficient is a number between 0 and 1. A low number is what you want. Usually, you want a number from .25 to .8. Lower numbers indicate better heat blocking capacity.

Next time you’re in your local home improvement store, check out their window selections and locate  the solar heat gain coefficient.

Summer Energy Efficient Windows

Summer in South Texas has arrived. The solar thermal energy heats up our gardens, our cars and our house. Solar thermal on a cold winter day is a welcome treat.

Solar thermal energy during summer makes my air conditioner run.

Most people frame their energy efficient windows discussion around saving heating costs in winter. However, during summer months, energy efficient windows work hard keeping heat out of our houses.

Energy efficient windows can cost several hundred dollars each. While good energy efficient windows will reduce your energy bill, don’t expect the energy payback to cover the cost of the windows. But your new energy efficient windows purchases and installed this year (2009) may qualify for a federal tax credit. Energystar.gov .

Read the labels on the windows your are considering.

The first thing to consider is the U-factor. The u-factor measures heat transfer and the numbers range from .25 to 1.25. This is a measure of how well insulated the window is. A lower number is better, meaning the window is better insulated.

We’ll talk more about windows next time.

Home Energy Efficiency versus New Energy

There appears to be a contest between embracing energy efficiency and going solar.

Why is every thing a contest? We all want the same thing:

•    Reduced carbon footprint
•    Reduced energy bills
•    Reliable energy source
•    Energy independence

Maybe it’s the government subsidies. Solar energy gets subsidies but home energy efficiency is the more cost-effective. One homeowner observed,

“Even with all the incentives offered [for solar], it pays me more to solve my problem by retrofitting the house.”

It does not have to be an either/or situation. In fact, wanting to go solar was our impetus to practice energy efficiency. The most cost effective way to clean the air of carbon emissions is to not put them there in the first place.

And the most cost effective home solar system is the one on the most energy efficient home.

Affordable Solar Within the Next Five Years

Making solar energy affordable to use for my home is my current goal. The current cost of installed solar, running about $10 per Kilowatt, takes my breath away.

Currently we are in the energy conservation mode at our house, trying to reduce our daily kilowatt usage to the bare minimum for comfort and efficiency. When I find that minimum, I’ll know how much solar energy I need to accommodate our needs.

I confess, even with the Incentive Tax Credits, I wonder when I will afford the solar.

But IBM just issued a report that gives us hope.

In the next five years, solar energy will be an affordable option for you and your neighbors. Until now, the materials and the process of producing solar cells to convert into solar energy have been too costly for widespread adoption. But now this is changing with the creation of “thin-film” solar cells, a new type of cost-efficient solar cell that can be 100 times thinner than silicon-wafer cells and produced at a lower cost. These new thin-film solar cells can be “printed” and arranged on a flexible backing, suitable for not only the tops, but also the sides of buildings, tinted windows, cell phones, notebook computers, cars, and even clothing.

Image by clownfish via Flickr

Lower Energy Bills — Build a Solar Home

All of us want to cut our energy bills. Some of us are retrofitting our homes to incorporate solar energy.

Others are building green, solar homes from the ground up.

Now with the new federal tax incentives it makes financial sense for retrofitters and builders alike.

The U.S. Green Building Council offers a Green Home Guide. The guide gives information on how to make your home more energy-efficient, tax credits and incentives and more.

Check out the Green Home Guide to help your energy efficiency and green home projects.

Here are a few more resources for you:

• U.S. Green Building Council:
• A state-by-state list of incentives
• Information on federal energy efficiency tax credits
• The EPA

How energy efficient is your home? In earlier posts I have suggested having a home energy audit done to determine how energy efficient–or inefficient–your house is. Learning how to improve your house “envelope” is the first step to going solar.

My do-it-yourself energy audit results were posted on September 8. The major air leaks I found with my simple tests were leaky windows, a leaky door due to worn out weatherstripping, and leaky electrical outlets. Yes, leaky electrical wall outlets.

Today is my official, professional home energy audit provided by my electric energy provider.

Please stay tuned! Tomorrow I’ll let you know the results!