Do ordinary curtains provide ANY energy/heat saving benefit?
Some years ago I read that “ordinary” curtains & miniblinds do not provide much in the way of energy/heat saving.
My housemate is sure her “ordinary”, unlined sheers (in the living area), thin cotton Battenburg lace (in the bath), and plastic venetian mini blinds in my bedroom provide energy savings if kept closed all the time. I say keeping every thing closed does nothing more than make the house look like a dark cave. Your opinion? And are there any so called energy saving curtains/drapes out there that actually help with heat savings, as they claim? Are there any on the market worth the cost? Most every wedsite I’ve looked at wants to sell something so they can’t be relied on to give an honest answer. Thank you for your time & thoughts.
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Replies
Kathlene,
You may want to read the following article (and the comments posted below): A Plague of Bad Energy-Saving Tips .
Here's a summary of important points:
1. Ordinary curtains usually don't save energy, but they can make you feel more comfortable in winter when you are sitting or standing near a window, because they interrupt the thermal radiation from your skin to the cold glass.
2. On sunny winter days, when the sun can help you heat your home, you definitely want to open the curtains.
3. Window quilts with air-sealed tracks on the sides, an air-sealed valance at the top, and a Velcro seal at the bottom, can save energy at night. Here is one brand: http://www.windowquilt.com/
Blinds and Curtains definitely help regulate thermal loss/gain through windows. Curtains and blinds do save energy. As Martin Holladay notes in his answer here, the savings are so real that you can feel them! They make you feel warmer by stopping that radiant heat from you body escaping the house. They save energy in other ways too. Why he says that very obvious truth and then tries to deny it is anyone's guess.
Now, are curtains as effective as modern, multi-glazed, low-E windows? Almost certainly not, since the modern windows keep heat in/heat out and let light in. But curtains and blinds definitely contribute to reducing both heat loss in the winter and heat gain in the summer. That is, in fact, why people invented curtains. So use those blinds and curtains for thermal regulation, but don't think that they are a substitute for high quality modern windows.