Are heavy drapes energy efficient?
mikeymo
| Posted in Energy, Heating & Insulation on
I have a friend who lives in a big old drafty Victorian house with big windows, in Chicago. She is wondering if getting big heavy drapes would be an energy-saver. Certainly when I’ve opened drapes in a house like that, it FEELS like you release a big pocket of cold air into the room. But are the drapes really keeping a lot of cold air out of the room? Has this ever been measured? R 1 or R10? Thanks.
Replies
mike
If the drapes are not sealed (in other words-making it a completely closed or partially open closure), there's going to be no real R value nor $ savings.
While you will not feel the cold glass directly in front of the window, the air movement that is generated behind the drape will introduce the same amount of cold transfer. No science used (so I could be wrong). Just remembering back 60 yrs to crawling around my parents living room.
At that time, I do remember them closing the drapes to "keep the heat in".
The "weight" of the drapes is
The "weight" of the drapes is not nearly as significant as their mere presence, and the degree to which they block the flow of air. Granted, without a tight seal around the edges there are still significant convection losses with a drape in place, but the overall heat loss through the window is roughly cut in half if the drapes hang close enough to the window.
However, getting the drapes to hang close enough to be effective can be difficult in a Victorian structure with wide window stools and other ornate trim features.
Window "quilts", which are made to hug the frame, can be more effective (but less attractive, and more of a PITA). (In fact, we had window quilts in the room I'm in right now, but removed them because the pulls were constantly failing.)
I agree with the other posters, but ...
but, if I may high jack the thread a bit, I saw something somewhere about exterior sliding panels which could be activated at night over the windows. Clearly not something for an exsisting house in an average climate, but if you live in the Yukon, maybe.
Seemed like a great idea to turn your R -1 windows into an R-20ish at night or when away from home. Probably a prefect appliation for someone building a home in the style of a barn (seems populare to some). You could build the sliding shutters to look like the old style barn doors with board and batten an the typicl X pattern across teh center. Not sure how they sealed the slider tight to the side of the house, as they would have the same problem as the drapes we have discussed here.
Just interesting.
Insulated shutters
Whether interior (which would make sense) or exterior-or both in hurricane country.
In our neighbors 1865 Thick Brick house-the interior shutters fold back to become recessed panels (jamb extension). On cold nites you'll find them closed up. The exterior shutters are operational as well-tho they don't close them.
Insulated drapes run in tracks all sides.
Those interior shutters probalby ...
only had an R value of about 1, assuming they were made of wood. Every little bit helps. Of course in an 1865 circa house you might have had drafty windows and then the value of the shutter would really kick in.
I thought the idea of 2 inch think foam sliders on the outside of a house to cover massive windows or entry slides was a need idea. Although not for anything I would be building, but a neat idea for the right house in an very very extreme climate.
You should look at honeycomb shades
Honeycomb or cell shades are made for this purpose and are much cheaper then drapes
Thanks!
Thank you all! I will forward the responses to my friend to sort through. I like the honeycomb shade idea. They are researching putting solar thermal panels on their old Victorian house... and wondering how much sense it makes to bother doing that on an old house. I say, if you're going to waste energy, it might as well be renewable.
Priorities?
I would swap out the leaky windows long before considering solar collectors. A much faster return on investment and an imediate comfort upgrade.
I too own a big old Chicago house.
Good luck.
NO return on investment with replacement windows
. Sorry but there is NEVER any return on investment with replacement windows. They will never come ANYWHERE even close to paying for themselves, and will need to be replaced over and over again.
. Replacement windows shoud never ever be considered for any home built before 1940. Lots of information here:
http://www.replacementwindowripoff.org
They do NOT save any energy and will actually decrease the value of your home. See the articles, including one from Fine Homebuilding, here:
http://www.replacementwindowripoff.org/articles
. With only one or two exceptions ever, I have never seen a home built before 1940 that benefited from replacement windows, and quite a few that have been ruined by them.
I agree with Mike here. If the window isn't properly sealed off then you will still have that cold air seeping in. There are other ways to save some evergy though. Tell your friend to make sure that the house is properly unsulated first, especially since you said the home was an old victorian. In my experience that has shown the greatest return on investment. Even though the windows are large, covering them with plastic does help... my dad used to do this when i was a kid. in the meantime, she could just use the drapes to cover up the ugly plastic look. Hope this helps.
insulation
Heat always moves to cold.
By putting heavy curtains in front of a window, you remove the flow of warm air that keeps the windows clear of condensation.
The space between the curtains and the window will become cold and all the moisture in the room will head for that cold window leading to windows running with condensation.
A better way, is to cover the windows with transparent plastic sheet, using tape to seal the plastic to the frame, this will create a cheap form of double glazing and will eliminate any drafts, keeping the room a lot warmer.
I use these, http://www.1windowquilts.com/
Absolutely. Although since heat energy moves form hot to cold, they are working more to keep your generted heat in rather than the cold out.
This is the same theory as medevil castles hanging heavy tapestries on the walls. They serves as more than something to throw chicken bones behind.