Edit: the interior size of the cooler is hopefully about 12x8. Working with about 14x10 footprint. Currentlty raw 2x4 airspace avalible on the 3 existing walls. The 12-14ft walls are parralell, one being the interior of the larger structure. It will be cooled with a coolbot hacked window unit.
Your insulation and your cleaning surface do not have to be (and are not usually) of the same material. A person could use straw bales, or cordwood, for the walls, for instance, and then clad those walls with something that is impermeable to moisture and further clad that with something that is easy to clean.
It seems as though the main concern is finding good vapor barriers and a surface that cleans well. Do you have a natural builder helping you?
When it comes to public safety fed law mandates professionals do the design not anyone off the internet or a non-pro DIY. That is a good thing for the most part. If it is not being enforced it may still be a good idea to follow it for obvious reasons.
I sacrifice my pie to you, because you gave the only answer, and not another question.
There was no rot. I don't recall a vapor barrier.
The material was kept clean, and I gave it to a landscaper. My best guess is that the cooler was built in the 50s.
Edit - There was no plastic vapor barrier. There was a thick aluminium sheet, about 4 times thicker than the stuff used as kitchen wrap. This was on the cold side, under the plywood.
Edit - There was no plastic vapor barrier.
Good info Dale, I'm getting ready to put a net-zero natural spec home to market with no plastic, foam, or vapor barriers, house wraps, osb, glues, etc, 100% breathable including the polished and sealed concrete floors.....I'm making a public presentation at a local home show on a 60 inch 4K 3D monitor of it in a week. All my suppliers think it is incredible, and all do not understand it. It is double wall construction. It is very interesting changing (or trying) the way people think and VERY time consuming. I hope to get many sold
I seem to remember reading about ships that carried ice from ice houses in new england, to southern states during the summer. Again, the ice blocks were packed in saw dust.
So I think the advice above, about using saw dust for wall insulation, is a very good idea. I'm not sure how saw dust compares to rock wool or sheep wool insulation for R-value, but would be considerably less expensive if you lived near a saw mill, and wasnt concerned about termites or fire proof qualities. Using double walls as recommended above eliminates thermal conduction through wood, which is a real concern in high R-value applications.
Maybe it is something to consider using?
R Scott wrote:Sawdust around ice blocks is not just a simple R value. It also dried the surface of the ice (wet ice melts faster than "dry" ice because water conducts heat faster) and cooled itself as the water evaporated off.
Good info and insight Scott. Many that know no better try and relate steady state r-values that do not apply. Enthalpy is far less understood. The reason I went to a double wall has nothing to do with u-or r-value or I can easily do that with single wall construction and the way most construct double they thermally conduct. Most do not understand "dynamic thermal conduction or r-value" or the conditions that real value is obtained and therefore advise inaccurately. Enthalpy works to create two independent enthalpy interior/exterior systems that can react to their respective boundary condition requirements. So in the case of a "natural material for a walk in cooler" a desiccant like aluminosilicate zeolite in a plaster would provide the evaporation cooling by phase changing a liquid vapor to a gas that heats the zeolite by heat of adsorption, that is an open loop (no sealed vacuum) system. Same happens with certain clays, limes, woods, etc, with high intracrystalline voids but not as fast. Materials of lower moisture content indexes (MCIs) don't perform as well, concrete is not as good as these materials despite the myths. Also zeolite is not damaged by the process. We just described a great way to manage indoor humidity with water vapor in liquid, condensation, or vapor form that cools a room and lowers HVAC requirements at a fraction of the cost. The desiccant, like zeolite retains 100% of it heat of adsorption with no loss.
At night when it gets cold and the dry hvac is running or the next day when the zeolite sees solar heat it reverses its process, converts a gas to a liquid that releases vapor or condensation back to the atmosphere for humidity buffering. Great part is as the heat is increased so is the amount of vapor. The desorption of heat and vapor is slower than adsorption for night time. The heat of condensation is released to it's surroundings lower heating bills. The cycle repeats.
Since these materials are chemically stable and insert there is no microbial growth in the presences of liquids and heat, unlike many plastics, foams, glues, used. These dynamic mass systems can accommodate any environmental conditions.
An entirely different independent system that handles a different set of exterior conditions can be designed on another wall/wythe. Airflow is the best insulator between the two wythes. Has nothing to do with r-value that would be HIGHLY misleading as usual. The math is complex, one has to assume an adiabatic process to quantify the dynamic hygrothermal systems. It should be obvious that adding a vapor barrier would ruin the process most would advise that know no better, same for house wraps that would ruin the systems. The same design can be applied to walls, roofs, foundations