Jenik -Your previous post made clear what I had negligently left unsaid about the role of convection currents in sb walls. Thanks. In response to the one below,: Jeff Christian's view of the failed ORNL R-value test (he backed up this view with CFD modelling) was that a convection cell the full height of the wall was established in the bales. This was only possible because the plaster was inadequately bonded to the bales, leaving vertical air channels. Somebody (I think it was Bruce King, from California, but I don't remember for certain) has suggested that all gaps between bales should be filled with straw-clay mix rather than loose straw. The reason given was to reduce fire risk, but it could also help to cut down the possibility of convection. As Dirk has hinted, though, bales laid flat will behave differently from bales on edge in this regard. Convective flow across the bale wall will be much lower in the case of bales laid flat (at a reasonable bale density, anyway).
Mark Jan Hollan wrote:
I remembered an email, I got years ago and found it in the forum. Would that be a possibility to solve the problem of air circulation (as far as it is...), to pack strawbales in wind-proof paper?:In our two insulating envelopes in Hostetin, we separated bales by paper at relevant surfaces. However, it's possible that convection cells are just of the size of about one bale, so separating the bales may not help much and surely cannot solve the problem completely. The improvement achieved by separating the bales is also something what should be investigated. jenik ____________________________________________________ European strawbale building discussion list Send all messages to: Strawbale@amper....muni.cz Archives, subscription options, etc: http://amper.ped.muni.cz/mailman/listinfo/strawbale ____________________________________________________