Air Pads losing pressure on a cold night. Is it possible?

**Mogollon Monster** · 12-11-2017, 17:14

I just took the kids out in the Tentsile Stingray over the weekend. We slept on air pads. To be specific we had an 2x Exped 9s and a Big Agnes Air Core. I've used these pads a bunch, and have always had good experiences with them. For some reason all three pads lost a lot of air. I'd say 30-40%. None of these pads have ever leaked before, so to have all 3 lose air on the same night, go me thinking that maybe it was the cold temps. The daytime temps were in the low 60s, but it dropped to 13 degrees by the next morning. Is it possible the cold temps caused a loss in cabin pressure, or do I need to start performing triage on all of my pads?

Thanks

Evan

**TrailSlug** · 12-11-2017, 17:19

Oh yea they have such a low volume of air that these would need to be re-inflated in those temps or way over inflated to start with. The real question is did you get CBS at those temps on these pads?

**Mogollon Monster** · 12-11-2017, 17:25

Originally Posted by TrailSlug

Oh yea they have such a low volume of air that these would need to be re-inflated in those temps or way over inflated to start with. The real question is did you get CBS at those temps on these pads?

No CBS. We stayed plenty warm, and since we were in the Stingray, we also were very comfortable, despite the air loss. In fact, less air in the pad was more comfortable than fully inflated. I just got worried that maybe I had a very expensive problem on my hands, with 3 pads getting injured on the same play. Thanks TS for the insight, you're always very helpful.

**TrailSlug** · 12-11-2017, 17:29

Well let's hope I'm helpful and they all haven't developed leaks. I know that the tubes I pull behind my boat in the summer have a ton more air in them and as soon as they hit the cooler water they too deflate quite significantly. The pad I used to use on the ground would loose as much as half of it's air when laid on the cold ground so I'm guessing that this is what happened.

**knightshade** · 12-11-2017, 17:33

Air volume shrinks with colder temperatures.
I can see a shift of 40 degrees making a pad needing to be topped off.

**fallkniven** · 12-11-2017, 17:51

It's the moisture in your breathe combined with the cold temps. That's why many use a pump. Thermarest makes a battery powered pump thats only an ounce or two. It eliminates the mold build up inside of the pad, and the air loss, which are all caused by the moisture in your breathe as you blow it up.

**gargoyle** · 12-11-2017, 18:02

When it warms in the AM, the pads should loft back up.
My little Thermarest pillow warms and swells, and cools and shrinks.
Not so much at night, but when I leave the pillow in the car. It can heat and swell pretty far.

**scrope** · 12-11-2017, 18:03

What I always do is to inflate my pad when I get to camp and then a couple of hours later then I'm ready to go to bed I top it off. After doing that I never had a problem with "losing" air in the middle of the night.

**dakotaross** · 12-11-2017, 18:21

I get low pressure warnings on my tires when it gets cold. So yeah, about the time its getting coldest is when your body temp is bottoming out. Especially if inflating with hot breath (I used to use an inflation bag). Only pad that could keep me consistently warm, unsupported by other insulation, is the Exped downmat.