How To Restore Loft To a Synthetic and Down Sleeping Bag?

Camping folks are worried about their sleeping bags not keeping them warm enough due to the loss of loft. Regardless of how you have treated your sleeping bag previously, you can still restore the loft in a sleeping bag. Let’s figure out how to restore the loft to a sleeping bag. Whether you have a synthetic or down sleeping bag, here are some useful ways to restore the loft.

how to restore loft sleeping bag

How Do You Restore a Sleeping Bag?

One of the most effective ways to restore some of the loft in a sleeping bag is by front-load machine washing on a cold setting on zero heat delicate cycle using a special soap and then tumble drying in a high capacity front-loading commercial dryer on air only setting with few clean tennis balls added.


In this article, I am going to share some effective ways to restore the loft of a sleeping bag. Whether you have a down or synthetic sleeping bag you should be able to restore the loft. So that next time when you go camping your sleeping bag will keep you warm enough. 

I have also included some preventive measures at the end to avoid the loft issues in the first place.

What Is Loft In Sleeping Bags?

The loft is a measure of the fluffiness in a sleeping bag. The fluffiness comes due to the air trapped between the fibers. As a result, the sleeping bag provides insulation and keeps you warm.

Sleeping bags come in a box baffle system. The fill inside the bag whether it be down or synthetic should be evenly distributed throughout the vertical portions of the baffles. This way your sleeping bag will function properly.

Normally what happens is over time with usage the fill inside the bag shifts at the top of baffles or around corners creating cold spots that lead to your sleeping bag not insulating the same way as it did before. So the lack of warmth is due to the loss of loft.

The solution to this is to bring back the fibers to their respective place. As a result, the fibers will trap more air between them and provide enough warmth.

How To Restore Loft To Down Sleeping Bag?

Shaking And Beating

The easiest way to restore some loft is to shake the sleeping bag from the foot end and then lay your bag out on the floor for a day. Make sure to not shake the sleeping bag vigorously. After doing that hang the sleeping bag and beat it with a badminton racket. 

The second way to restore your sleeping bag is to treat it like a pillow. Punch and clap it. Move your hand to the bag. Gently massage your sleeping bag. Feel the dense clumps. Break up the clumps by hand.

If none of these methods work then it’s time to wash your sleeping bag. Dirt, dust, natural debris, oil buildup, and body sweat are holding the clumps together. In order to break up the clumps, you need to wash the sleeping bag.

You can either hand wash in a bathtub or use a high-capacity front-load washing machine. Top-load washing machines are rough and can rip the bag.

Front Load Machine Washing

Unzip the sleeping bag and lose the drawcords. Set the front-loading washing machine on a gentle cycle. Most bags can be washed in warm water. Check the manufacturer’s recommendations on the care label. 

Use a special downwash. Nikwax downwash is recommended. Check the instructions on the cleaner to see how much to use.

Give it a second rinse to wash out all the soap. Once washed, remove the sleeping bag from the washer and put it in the dryer. Wet down is very heavy. Support the bag from below to prevent damage to the baffles.

Tumble Drying

Set the front-loading dryer on air only. Heat can damage your sleeping bag so be careful. Add 3-4 clean tennis balls to help break up the down clumps. Remove the bag from the dryer every 30 minutes and break the clumps gently by hand. 

After drying the sleeping bag, hang it in front of a bright window to check for cold spots. The light should not pass through your sleeping bag.

This method should revive your sleeping bag completely. If this method doesn’t work then it’s time to replace the bag. You can also send your sleeping bag to the company to add more fluff.

How To Restore Loft To a Synthetic Sleeping Bag?

For a clean and dry synthetic sleeping bag, the shaking and beating method as previously mentioned for the down bag should restore the loft.

If that method doesn’t revive your synthetic bag that means you need to wash the bag.

Synthetic sleeping bags also lose loft due to oil buildup and human body sweat.

The way to wash a synthetic bag is the same as a down. When tumble drying the synthetic sleeping bag you don’t need to use the tennis balls.

Don’t use clothes washing detergent. Use a soap specially made for your synthetic fill.

Synthetic sleeping bags don’t respond to cleaning the same way as the down. So don’t expect the same loft after cleaning. 

They lose their loft more quickly and the chances of revival are less. Therefore, you should take preventive measures in order to prevent the loft issues from happening.

If you don’t want to wash the sleeping bag at home consult a professional cleaner. Rainy Pass Wash offers a sleeping bag cleaning service.

Tips To Increase The Loft

Loss of loft occurs due to over-compression and improper storage of your sleeping bag. High-quality downfill is more durable, compressible, and resilient. 

According to Feathered Friends, there is no limit to how much you can compress a high-grade-down fill sleeping bag. However, make sure not to leave a dirty sleeping bag compressed for a long period of time in a compression sack.

Down is more resilient to compression than synthetic. PHD(phdesigns.co.uk) did a test a couple of years ago to find the impacts of compression on down and synthetic material. 

They found that after thousands of repeated compression cycles on synthetic material, it lost about 30%-40% of its loft. While the down was 5% loftier than before.

This indicates that down is more resilient to compression than synthetic. But the only thing to be careful of is never to leave a dirty wet-down sleeping bag in a stuff sack for a long period of time.

Over-compression causes damage to the fibers that would otherwise contribute to increased loft. Loft degrades more quickly in synthetic sleeping bags.

You should either store your sleeping bag in a large breathable cotton bag or hang it in the closet loosely to avoid the loft issues in the first place.

Apart from that, when packing the sleeping bag in the stuff sack for camping, always stuff the sleeping bag. Never roll the sleeping bag. 

It will not only save you a ton of time when packing but increase the lifespan of your sleeping bag. Also, you will not have loft issues later. I have a helpful article on this topic that describes in detail why stuffing is better. Check it out here. Roll or Stuff a Sleeping Bag?

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