I'm cold-blooded, and also cheap. So I keep a down comforter on my bed shortly after autumn gets in full swing, in the interest of keeping myself as warm as possible while sleeping with the thermostat turned down as low as possible. I leave another down comforter on the livingroom sofa, too, for staying warm while I curl up with a book evenings. Love my down comforters! And great thing I learned about them a few years ago is that you can safely launder a down comforter.
Now, I don't actually launder a comforter very often. In fact, I probably launder them only every other year. I usually find that it does the trick to let them air out a couple of times during the winter, and then give them one good airing out by a warm, sunny window in the spring before storing them away for the summer. Here's a roundup of things to do to keep your comforters in good shape for longer.
1. Use a duvet cover, and wear pajamas. The goal here is to minimize how often you launder the comforter by keeping your sweat, drool, and smelly feet from dirtying the comforter case or permeating the down filling with odors. The less often you launder anything, after all, the longer it will look and feel like new. So buy or make a machine-washable duvet cover to protect it. Get two, so when you have to launder one (got cats?), you have another one waiting for you in the linen closet. If your comforter didn't come to you with its own removable cover, lay the comforter out, measure it, and dig your favorite catalog, website, or retailer for one that fits. Or score a few king-size sheets and break out the sewing machine, if you're feeling extra cheap. While it may feel irritating to have buy what's essentially a gigantic pillowcase for this blanket, remember that it'll feel even more irritating to find an indelible stain or undefeatable odor in the comforter in a few months because you didn't protect it.
Wearing some kind of nightclothes as a further barrier between your skin and the comforter will also go a long way toward keeping the comforter fresh. This is a no-brainer for me, because I'm so cold all the time. Paradoxically, though, if you tend to sweat a lot at night, you have even more reason to wear pajamas than I do. You'll have to change your sheets less frequently, and it'll be better for your comforter.
2. Air it out every few weeks. Remove the duvet cover and launder it. Shake out the comforter to evenly distribute the down. Lay it out over a couple of chairs or sturdy clothes drying racks. If you can, set it by a window so that some sunlight can hit it. Let it air out for at least 24 hours, or over the weekend. Then put it back in the duvet cover -- be sure that the duvet cover is 100% dry -- and toss it back onto your bed.
3. Don't be afraid to launder a comforter, but don't do it often. Comforters filled with real down don't come cheap (though, to tell the truth, one of mine was a gift, and I trash-picked the other, Penn Christmas-style, from the trash pile of a neighbor who was moving out). They do need to be deep-cleaned every once in a while -- you'd better believe I laundered the trash-picked one before I used it -- in a way that only laundering in water will do, yet no one wants to ruin an expensive comforter.
First of all, unless it's an emergency (got cats?), wait until the weather warms up. That way, you'll be able to set it outside or by a sunny, open window to really make sure it's dry before you put it away for the season. Now take a gander at the comforter's cleaning instructions. It probably tells you to take it to a professional cleaner. This is "CYA"; you can do the job at home if you have a very large washing machine, or at a laundromat if you don't. Use a mild Woolite-type soap, not detergent, and rinse it at least one extra rinse. Then toss it in an extra-large dryer on low heat. I've seen it advised to put a clean canvas athletic shoe or tennis balls in the dryer as well, to even out the down stuffing; however, I've found it just as simple to stop the dryer every once in a while and gently shake out the blanket instead.
After you run out of quarters or just don't feel like hanging out in the laundromat any more, take the comforter home and lay it out on the chairs or clothes racks for at least 24 hours. If the weather is warm, set it by an open window for some extra UV sterilizing, like I did with my daughter's cloth diapers back in the day. Careful, though! If the pollen is out, a significant amount could fall on the comforter, and you may find yourself mysteriously sneezing when you take it out again next autumn.
4. Fold loosely for storage. When the comforter is totally dry and the house is truly too warm to have it on the bed at night, gather it up, fold it gently and loosely, and store it in a dry, moth-free closet. Since you don't want to compress the down, don't store it in a plastic bag. One idea is to store it, folded, inside a duvet cover, which saves a duvet cover's worth of space in the linen closet during the summer.
And that's that. Four E-Z steps to toasty-warm rowhouse livin' with a down comforter when the temperature falls.