Is there a reference anywhere listing pros and cons of various beddings to use on top of a thermal mass bench? I am looking for materials that would fit Wheaton Labs standards, no synthetic/plastic elements, no chemical applications.
The only example I've come across has been the
DIY buckwheat hull mattress in the Wheaton Labs tepee. This mattress was installed ten years ago. I slept on it a couple of nights last winter. It was a bit too firm for side sleeping, being uncomfortable on the hip. I was more focused on the RMH function and didn't think to try fluffing up the pods to see if it was needed periodically for softening. Over summer it was replaced with a straw tick mattress but I haven't heard any feedback on how that has been working. I think the buckwheat pods were reused in a different location but again haven't heard more about that.
For the first week I've had my RMH running I've used a futon mattress I've had sitting around. It is about 2" thick and I'm not sure off hand what it is filled with (cotton?). It feels similar to my experience with the buckwheat hull pods in that it is generally comfortable but makes my hip hurt when side sleeping. It traps the heat in the mass under it and holds the heat until morning quite well, making me a bit too warm at times if the heater has been running most of the evening.
The site that sells the buckwheat hull system also has hemp sand fill to be used with a mattress topper case. They suggest pairing this with a layer of natural latex in another case.
I think there are four relevant qualities to note here. First, how do the materials deal with ongoing thermal extremes? My mass has not reached anything painful, but when I pull back the futon and touch the surface it can get to the upper end of what I would consider comfortable. If I am gone for a couple of days, the mass will return to ambient so would likely see -10 to -20*F. This is about what the tepee mattress experienced so I'm curious if that degraded the hulls or what kind of life would be expected of them. 10 years isn't bad if those are the originals and would be softer when fluffed.
Second, how does a material (or combo) deal with the mass, eg retain or radiate the heat from below and conform to irregular shapes. I haven't heard this explicitly discussed with the tepee buckwheat hulls, but did form the impression somewhere that heat would pass through the hulls better than more conventional bedding materials. The pod system is ideal in customizing shape. The futon is floppy enough that I can fold it around irregular parts, but this is a bit clumsy. It sounds like the hemp sand topper system would be similar to the futon, though perhaps a bit better for shaping. I don't think a conventional mattress would work well at all.
Third, how much 'cush' do the materials offer? I could just lay out a few wool blankets to have something that would deal with the heat fine, but have a feeling that wouldn't be any more comfortable than the futon mattress.
Finally, cost. The buckwheat hulls from OYEB would be around US$600, the hemp closer to $1000. I could make something custom for a fraction of that, and would consider that in theory at this point, but won't have time to dedicate until more infrastructure is built here so looking for something no more complex than filling and tying tubes. I would also like it for this winter so not a good time to go harvest straw or anything like that.
I guess there are other things implied here like fire and bug resistance. I think anything mentioned here handles that so would only be something to check if considering something entirely new.
2
