A lot of winter campers, myself included, use a down filled air mattress (DAM) for extra warmth as part of our sleep system. With R-values of 5 and above, they really boost your comfort level when it is below freezing.
How to Inflate a Down-filled Air Mattress
The problem with inflating a down air mattress is that you don’t want to blow into it and introduce moisture that will degrade the insulating properties of the down fill. If you have “accidentally” done this, perhaps out of impatience, you can revitalize your down air mattress by drying it in a dryer, set to low heat, with the valves open.
The right way to inflate a DAM is to use a pump to inflate it with ambient air. Winter air is much drier than your breath and won’t degrade the down insulation.
Some down air mattresses such as the Exped Downmat 7 or Downmat 9 now come with a built-in pump, while others such as the Warmlite or the Ultralite KookaBay DAM (18.2 oz) require that you use an external pump, such as the Big Agnes Pumphouse, to inflate them.
The Pumphouse is a stuff sack with a nozzle-like fabric tube at one end that is universally sized to fit onto any air mattress valve. There’s a cord-lock at the end of the nozzle extension that lets you secure it under the base of a valve so it won’t come off during inflation, a common problem for me with the old Exped pump system.
Here’s a short video that shows how to use the Pumphouse to inflate an air mattress:
My friend Jason Klass recently posted an article about another pump for filling air mattresses, called the Instaflator. It’s a long plastic tube which lets you inflate an air mattress which one “pump” of air. It’s kind of cool, but it serves no other purpose in your pack and is so long, that you may need to stand outside your shelter to inflate your air mattress.
For my money, I like The Pumphouse better because it serves multiple purposes and you can use it in a shelter regardless of the weather outside. Effort-wise, it only takes 15-20 pumps to inflate an air mattress, which probably won’t kill you if you’ve managed to hike most of the day to your campsite.
Disclosure: The author owns this product and purchased it using their own funds.