The Real Test of a Sleeping Bag Isn’t in a Lab

One of the questions we're often asked is whether our sleeping bags are ISO or EN certified. It's a fair question. We've used these tests ourselves over the years and understand their value - but after decades of designing, manufacturing and sleeping in our own gear, we've learnt they only tell part of the story.

For all the equipment we make, we personally test it in the environment. Because the real question isn't "What's the number?" It's "How will this bag perform for me?"

What the official lab test actually does

The industry standard test (EN 13537, now largely replaced by ISO 23537) places a heated thermal mannequin inside the sleeping bag in a climate-controlled chamber, then gradually lowers the temperature and measures how the mannequin responds.

What it doesn't measure

A lab test is conducted under one controlled set of conditions. It can't account for all the things that determine how warm you'll actually sleep:

• Who's in the bag. People run at different temperatures. Women generally sleep colder than men, for instance.
• Inner sheet liners, which add warmth on top of the base rating.
• Clothing and headwear worn to bed.
• Sleeping mat insulation.
• Tent insulation and windchill.

It also doesn't measure breathability. A silver-lined bag can score a better lab warmth rating while sleeping clammier and less comfortably.

How we rate our sleeping bags at Snowgum

Over the years we've submitted plenty of our sleeping bags for these lab tests. Today, we no longer submit every model for certification. Not because we don't value the testing, but because we've found it only provides part of the picture. Instead, we base our temperature guidance on manufacturing experience and field testing.

Our factory has tested sleeping bags with the same fill quality, fill density and shell fabric many times, and the temperature rating we offer is based on this experience.

Just as importantly, we use our own gear. My daughters and I slept in the current Stirling model in -10°C in Nepal in December 2024. Based on that experience, we're confident the Stirling is suitable for any Australian conditions and global alpine conditions down to these sorts of temperatures.

Getting the most out of a down bag

If you haven't owned a down sleeping bag before, there are a few things worth knowing:

• Store it loose in its storage bag, not compressed.
• Keep it dry whenever possible.
• Use a sleeping bag liner to keep the down clean.
• Air it thoroughly after each trip before storing.

I've had my own down sleeping bag for over 40 years and it's still going strong. Our goal is for the Stirling to last you a lifetime.

Why is the Stirling priced so competitively?

If you've compared the Stirling with similar sleeping bags, you've probably noticed it's priced well below many competitors. People often ask us why.

The answer is simple and it applies to everything Snowgum. We source the components and immerse ourselves in the production process directly, in every factory, with our own experienced team. There are no middle men, no trading houses, no importers to take a clip on the way through. We are delivering you the best possible value in every single Snowgum product. It's not a trick. We've been around since 1986, we stand behind every product we make, and we're confident you won't be disappointed.