Mt. Washington vs. NightLight pad

[Stephan Guyenet]

Okay, I’m confused. The Mt. Washington pad is claimed to have an R-value of 3.2, based on the review on this site entitled “Closed Cell Foam Sleeping Pads”.

It weighs about the same and is about the same thickness (3/4″ max) as the GG NightLight pad, which is supposed to be a reincarnation of the Mt. Washington.

Yet the NightLight is supposed to have an R-value of only 2.27? What gives?

One of these numbers must be wrong, and I’d love to know which one it is. It seems to me that the NightLight should be more than .07 warmer than the Z-rest (2.2), which is just a thin convoluted foam.

[Bob Gabbart]

There was just a post about this earlier. The article is wrong. It has an r-value of 2.27.

[Stephan Guyenet]

doh

[Stephan Guyenet]

doh

[Stephan Guyenet]

Don’t you think it’s a bit strange that the NightLight is only slightly warmer than the Z-rest? It seems like it should have a higher R-value, judging by how it’s built and what I’ve heard from people who have used it. Any thoughts?

[Michael Martin]

Stephan writes:

>> Don’t you think it’s a bit strange that the NightLight is only slightly warmer than the Z-rest? It seems like it should have a higher R-value, judging by how it’s built and what I’ve heard from people who have used it. Any thoughts?

I’ve used both the Z-Rest and original Mt. Washington pads. R-values not withstanding, I’ve found the Z-Rest to be cooler. I attribute this to the edge effects of the mats (which are not reflected in the R-Value). The Z-Rest ridges allow more cold air to circulate under (and maybe over) the pad than the Mt. Washington. I haven’t tried it, but if you could seal off the Z-Rest edges on top (perhaps with your bag) and on the bottom (maybe with duff?), it should be warmer.

Cheers,

-Mike

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