If I’m being completely honest with you I would say that I’ve always believed down to be superior to synthetic fills in most situations. However, inspired by the recent release of Nemo’s new FeatherCore insulation which claims to be just as light and compressible as 650-fill power down I think it’s time to take a deep dive into a synthetic vs down sleeping bags.
How are they different? How are they similar? Why might I want one over another? We’ve got all those answers and more within this post. It’s important for the serious
What is Down?
Down is a layer of fine feathers found underneath the harder exterior feathers of birds. It has been used by humans for centuries and held an important place in the culture of indigenous Americans. Nowadays’s it is used to fill sleeping bags, jackets, blankets, pillows, and other similar products. The down used commercially is most often duck or goose down.
In some areas of the world, mainly Iceland and Scandinavia, people still collect down from wild eider ducks however most of the worlds down now comes from domestic geese. When buying down products, make sure to check that they are certified by the Responsible Down Standard (RDS) which ensures humane treatment of geese and ducks.
Humans have tried to produce man-made materials that replicate the qualities of down. Fluffy down feathers trap air which makes it an excellent form of insulation. But, although we have developed many fabric materials that match down as far as warmth goes, something we have never been able to reproduce quite as effectively is the outstanding warmth to weight ratio. Down is highly compressible which is how full-size sleeping bags, like this one, can pack down to the size of a grapefruit!
Down comes in different fill powers. This is a number that indicates the amount cubic inches displaced by a given ounce of down. That sounds really technical but all you really need to know is that the higher the fill power number is the better the insulation is for the same weight.
Premium sleeping bags, like those made by Western Mountaineering and Feathered Friends, often use 800 or higher fill power, which means they can stay extremely warm while remaining lightweight and highly packable. Those who want an ultralight bag or plan on backpacking in extreme cold use bags with higher fill powers. However, fill power in the 500-650 range is good enough for most conditions and still provides an awesome warmth to weight ratio.
What is Synthetic Insulation
Synthetics are man-made materials used to fill sleeping bags instead of down. While down is loose material, synthetic insulation is usually held together in sheets.
The main draw for synthetic insulation is that it is able to retain most of its insulating capabilities even when it gets wet. Whereas down becomes useless when wet and dries very slowly. However, innovators have been continuously working on this issue and there are now down fills treated to be more hydrophobic, that is, they repel water and still provide insulation even if they get a little wet. The effectiveness of these hydrophobically treated down fillings also varies. The outer fabric of down sleeping bags, if waterproof or resistant, can also help to mitigate this issue.
There are endless types of synthetic insulation on the market nowadays, with each manufacturer attempting to mimic the quality and benefits of down filling. There are some that get quite close, and Nemo now claims to have matched or beat the leading 650 fill power down bags on the market with the new Azura, Kyan and other sleeping bags.
General Pros and Cons
Whether you choose synthetic or down insulation is up to your personal preference and desired activities. If you often find yourself in wet conditions or want to take a canoeing or rafting trip, a down bag may not be the best choice. Likewise, if you’re a car camper and don’t really need to worry about lugging your gear around on backpacking trips, synthetics, being cheaper, may be a wise choice.
I myself, prefer down because it lasts longer, and I can use it for backpacking as well as regular camping. I don’t often find myself trapped in very wet conditions either. Though, as a general rule, down sleeping bags are more expensive they don’t have to break the bank. You can find a number of reasonably priced down bags in this article. Or, if you’ve got a bigger budget and are looking for something higher end, read this one.
Here’s a TL;DR quick reference table of some general pros and cons although some may be less relevant depending on the specific sleeping bags you’re looking at.
Manufacturers have been claiming to have the secret sauce synthetic insulation, to match down filling, for years. So I have to admit that I’m a bit skeptical about the FeatherCore claims. However, Nemo is a great company with cutting edge sleeping bags of all styles and types. I’m eager to look deeper into the new insulation and make up my own mind about the claims.
If it truly is as packable, lightweight and effective as down, these synthetic sleeping bags might just be the closest thing to perfect that we’ve ever seen in the sleeping bag market. Taking the pros from the down filling side of the table and combining them with the water resistance of synthetics, it’s an all-around great solution for nearly any situation. And, at around $200 for a 20º sleeping bag, the price is definitely right!
Let us know in the comments what you think of Nemo’s recently released insulation. And if you have any questions about anything in this article feel free to drop us a line as well!