Down vs synthetic sleeping bags for hiking

Key highlights: Down sleeping bags, known for their longevity and excellent warmth-to-weight ratio, are generally superior for outdoor activities. They pack smaller and lighter than synthetic bags, making them a popular choice for hikers. However, synthetic bags are more affordable, dry faster, and handle moisture better, which could be advantageous for activities where water exposure is a risk or in damp conditions. It's essential to manage condensation in both types, with proper bag care, checking tent conditions, and ensuring good ventilation.

Which Is the Better Choice?

One of the most common questions I get is about the differences between down and synthetic sleeping bags. Both have their pros and cons, but in general, for most outdoor activities, down sleeping bags are the superior option. Bogong Equipment’s product range reflects this, with only 6 out of their 58 sleeping bag models featuring synthetic fill.

Why Is Down the Better Option?

Longevity: Down is one of the most remarkable natural fibers, known for its resilience and longevity. When properly cared for, a down sleeping bag can last for many years, often outlasting the life of its shell. Synthetic fills, on the other hand, tend to compress over time, losing their loft and warmth. In our experience, a well-maintained down bag typically lasts three times longer than a synthetic one.

Warmth-to-Weight Ratio: Down excels in providing the best warmth-to-weight ratio of any material available. Not only does it offer superior warmth for its weight, but it also outperforms synthetic materials in terms of compressibility and pack size. Simply put, for a given warmth level, a down bag will pack smaller and lighter than a synthetic one. For many of our customers—whether hiking, ski touring, traveling, or cycle touring—this compactness is a crucial factor in selecting the right sleeping bag.

Advantages of Synthetic Sleeping Bags

Price: Synthetic sleeping bags are more affordable upfront compared to down-filled bags. However, considering longevity and performance, they may not always offer better value in the long run. The cost-saving needs to be weighed against the overall utility and durability of the bag.

Better Performance When Wet: Synthetic fills absorb much less water than down, meaning they dry faster and are more resistant to moisture. This can be a key advantage in conditions where water exposure is a risk, such as kayaking or river rafting. It’s much easier to care for and dry a synthetic sleeping bag in the field compared to a down bag, which can be challenging to dry after becoming sodden.

That said, many down sleeping bags are designed with water-resistant shells to help protect the down from moisture.

General Camping: For general camping, where weight and size are less critical, a synthetic sleeping bag may be the more practical choice. If you’re camping in areas with a lot of dust or dirt—like climbing campgrounds—it may be easier to maintain and clean a synthetic bag.

Condensation: A Factor to Consider with Down and Synthetic Sleeping Bags

In addition to moisture resistance, it’s important to consider condensation—something that can affect both down and synthetic sleeping bags in different ways.

Down sleeping bags rely on air pockets to trap warmth. However, they are more susceptible to moisture, as even slight dampness can cause the down to clump or compress, reducing its ability to insulate. This makes down bags less effective in conditions where condensation or humidity is a concern. Synthetic sleeping bags, on the other hand, are more resistant to moisture and maintain their insulating properties even when damp, making them a more reliable option in damp or humid conditions.

Why Does Condensation Occur?

  • Moisture Management: Down bags require more careful moisture management. Condensation can form from the humidity in the air, especially in colder temperatures, leading to moisture on the outside of the bag. Synthetic bags tend to manage this moisture better, as they don’t lose their insulating properties as easily when wet.
  • Sleeping Mat: A sleeping mat that doesn’t offer adequate insulation can allow moisture to seep from the ground, potentially affecting the bottom of your sleeping bag. If your tent is leaking or the ground is damp, moisture could accumulate between the mat and the bag, contributing to condensation inside.
  • Ventilation: Poor ventilation can also cause moisture buildup. Even if you’re not sweating, your breath and body humidity can lead to moisture inside the bag. Down bags, being less resistant to moisture, may be more prone to this issue. A synthetic bag, with better moisture resistance, can handle this humidity better.
  • Bag Fit and Compression: If your down sleeping bag is tightly compressed or doesn’t allow for sufficient airflow, moisture may accumulate inside. Synthetic bags typically have a looser fit, which promotes better air circulation and reduces the likelihood of condensation.

How to Manage Condensation and Moisture:

  1. Proper Bag Care: Keep your down sleeping bag as dry as possible, and consider using moisture-resistant treatments to help prevent issues.
  2. Check Tent Conditions: If condensation isn’t visible on the ceiling or walls of your tent but your bag is still getting damp, it may be due to trapped moisture between the mat and bag.
  3. Ensure Proper Ventilation: Make sure your sleeping bag is ventilated correctly. Most down bags have built-in features to help with moisture venting, and you can also sleep with your bag slightly open for better airflow.

Choosing the Right Sleeping Bag for Your Adventure

Ultimately, the decision between a down or synthetic sleeping bag depends on your specific needs and the conditions you’ll be facing. Down sleeping bags offer exceptional longevity, warmth-to-weight ratio, and compactness, making them the top choice for most outdoor enthusiasts. However, synthetic sleeping bags shine in damp or humid environments, where moisture resistance and ease of care are more critical.

Both options have their advantages, so it’s important to consider factors like the type of activity, expected weather conditions, and how much you’re willing to invest in long-term durability. Whether you’re planning a multi-day hike, a ski tour, or a casual camping trip, choosing the right sleeping bag can make all the difference in your comfort and performance.


For a detailed breakdown of which sleeping bag best suits your needs, check out our blog post Which is the Best Sleeping Bag for You?

Contributed by: Bogong Equipment

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About the Author

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Darren Edwards is the founder of Trail Hiking Australia, an avid bushwalker, and a dedicated search and rescue volunteer. With decades of experience exploring Australia's wilderness, Darren shares his passion for the outdoors, providing practical advice and guidance on hiking safely and responsibly. He was interviewed on ABC Radio and ABC News Breakfast to discuss bushwalking safety, highlighting his commitment to promoting responsible outdoor exploration.

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