Hilleberg Nallo 2 Frost and Condensation

Hi Yang

It is not the tent itself. Under certain conditions ANY fabric surface will collect condensation at night. There are many threads and some articles here on BPL about it.

However, closing your tent up and eliminating any air circulation will make the problem a lot worse.

Cheers

Roger is right on.

The Black Diamond (or earlier Bibler ToddTex) fabric will get frost from frozen condensation just as much as anything else. Maybe one of the worst nights I ever saw was two of us in a Bibler Fitroy one 4 F night.

Thanks Roger and Raymond. Next time I will open it up.

This is the lesson I learned. I only knew that when the air was saturated, which means not frozen, tents can get condensation, but I did not know when it is frozen, it can get condensation as well. I guess this is because the frost clogged the pores of inner tent. So the moisture has nowhere to go.

Yang,

Your bag is "wet at the upper end near the mouth" from you breath. And the foot of the bag can get wet form touching the frosted tent wall and melting the frost.

I put my zipped up parka over the foot of my sleeping bag to protect it. Also this gives the foot area some extra warmth. Close down the hood as much as possible too.

Keep your boot liners INSIDE your sleeping bag and boot shells "telescoped" together so keep out blowing snow when they are stored overnight in the tent vestibule. Warm boot liners are a Godsend on bitter cold mornings. Freezing toes are painfully miserable.

The moment the vapors you exhale contact that 14F tent fabric they'll freeze. You'll have this no matter what.
You ventilate so you minimize it.

Happy New Year Yang. While I don't have a Nallo 2, I have another Hilleberg, the Allak, and I imagine the inner and fly ventilation mechanisms are the same.

I've had great experience snow camping with it with two people without condensation issues just by unzipping a few inches of the outer fly door at the highest point under the cap that sits over the tent poles and fly. The fabric inner door under that is breathable.

If you need even more ventilation, you can unzip the fly door a little more, and you can also open up the inner door zip at the apex of the door.

I've found it very easy to minimize condensation, while keeping out drafts and keeping warmth in.

"This is the lesson I learned. I only knew that when the air was saturated, which means not frozen, tents can get condensation,"

Look up ice fog using Google. Condensation can occur at any temperature.

http://en.wikipedia.org/wiki/Ice_fog