When the topic of your windows’ job in regards to energy efficiency arises, there’s almost a bipartisan split of opinions that’s more recognized in political debates. One side of the spectrum is passionate that replacing windows is a highly overrated “green” renovation which should be vacated and the budget focused elsewhere. The pro-window replacement crowd rebuts that it’s useless to upgrade an HVAC system or boost insulation if heated (and cooled) air is going to continually be lost out inefficient windows.
In reality, wanting homeowners to replace their windows to improve energy efficiency is a blanket statement that depends on a lot of variables. If your windows are already double-paned, the savings and increased comfort from installing new Energy Star models may not provide the return on investment you’re looking for. Then again, getting rid of old single-paned windows and upgrading to modern energy efficiency models could save hundreds of dollars in heating and cooling bills per year. A lot also depends on your climate and the layout of the home (where the sun hits, tree for shade in summer, surrounding buildings that block wind in winter, etc.).
So the question becomes, “how do I know if my windows are efficient enough?”. The best time to find that answer is in the winter when cold drafts in a room are noticeable and temperatures from the outside air can be detected by touch. Here are some tips on determining whether an inefficient window upgrade should be considered.
What is the Window Framed in?
The window glass, including glazing, insulation, etc., is not the only important factor to a window’s efficiency as the framing itself also dictates heat loss. Wood framing, for example, expands and contracts as the weather changes, creating gaps where air can enter or escape the home. Aluminum frames tend to transfer heat easily, which sends warm air to the outside. Unless your windows are framed in a material such as insulated vinyl, some temperature loss is almost inevitable.
Check for Insulation Around Window
One way to combat the changes involved in framing material is with insulation around the gaps in the window opening. Believe it or not, some contractors either forget to add this insulation or do not do an adequate job of filling in this small, yet problematic, space. Window insulation is installed from the inside of the home and the best way to determine the current situation is by popping off the trim from the interior of the window and having a look inside.
Is the Window Single-Paned or Double-Paned?
The only place you should find a single-paned inefficient window is in an unfinished garage or in a cabana on a tropical island. Many older homes still have their original single paned-windows (and possibly a storm window outside) which are viable sources of heat loss. If your house falls under this category, you should start to create a budget to at least swap out these windows one by one, if not all at once. Modern windows are double or even triple-paned and feature insulated gas as well as special UV protective coatings, so that not only will the comfort of the room be noticeable, so will the lower utility bills.
Do the Inefficient Windows Just Need Repair?
If you notice condensation or a fog on the windows, it could mean that the insulating gas has leaked and the windows aren’t providing as much thermal resistance as they should. There may also be a crack in the window or sometimes a piece of the frame has decayed from water exposure. If one window feels noticeably draftier than others, it could just need repair or a single replacement.
Reasons for Replacement Besides Energy Efficiency
Finally, there may be reasons your windows are inefficient and it has nothing to do with heat loss. Lets not forget that windows are not only functional, but provide aesthetics as well. If your current pieces are noticeably out of style or you are getting new siding on the exterior, it may be time to think of a window makeover. Also, if the windows you have now don’t open or have broken fixtures, they should be replaced or repaired to avoid a potential fire hazard.
If after evaluating all these factors you’re still on the fence about whether you have inefficient windows, you can contract a home audit to get an expert opinion. These energy assessments include thermographic scans, blower door tests and air infiltration measurement among other things to determine if loss is coming through the windows or somewhere else such as the ducts.