Windows
Windows can account for up to about one quarter of your heating bill during
the winter months, so it is well worthwhile making sure that these are properly
insulated.
The most obvious way of doing this is by either double glazing or secondary
glazing - the first well known to all home owners, the second perhaps not
quite so well known. New doublepane windows with high-performance glass
are widely available from suppliers keen to cash in on this profitable sector,
so make sure you research this properly to find a reasonably priced reliable
company. Don't make the mistake of being seduced by the extravagant claims
made in Yellow Pages, unfortunately these are very often used by companies
that rely on the power of marketing rather than on providing good economical
service. Try asking everyone you know - there's nothing better than a personal
recommendation.
Ask for advice on whether you would be better with windows that are gas
filled with low emissivity (low-e) coatings on the glass to reduce heat
loss, generally better in cold climates. In warmer climates, select windows
with spectrally selective coatings to reduce heat gain. Remember that, if
you are building a new home, you can offset some of the cost of installing
more efficient windows since doing so allows you to buy smaller, less expensive
heating and cooling equipment.
If you decide not to replace your windows, the simpler, less costly measures listed below can improve their performance.
Cold-Climate Window Tips
* You can use a heavy-duty, clear plastic sheet on a frame or tape clear
plastic film to the inside of your window frames during the cold winter
months. Remember, the plastic must be sealed tightly to the frame to help
reduce infiltration.
* Close your curtains and shades at night; open them during the day.
* Install tight-fitting, insulating window shades on windows that feel drafty
after weatherizing.
* Keep windows on the south side of your house clean to let in the winter sun.
Shopping Tips for Windows
* Remember, the lower the U-value, the better the insulation. In colder climates, a U-value of 0.35 or below is recommended. These windows have at least double glazing and a low-e coating.
* In warm climates, where summertime heat gain is the main concern, look for windows with double glazing and spectrally selective coatings that reduce heat gain.
* Select windows with air leakage ratings of 0.3 cubic feet per minute or less.
* In temperate climates with both heating and cooling seasons, select windows with both low U-values and low solar heat gain coefficiency (SHGC) to maximize energy benefits.
* Remember that new windows must be installed correctly to avoid air leaks around the frame. Look for a reputable, qualified installer.