Registered: 1441204777 Posts: 1
Reply with quote #1
I'm looking for a list of
volumetric heat capacities of various building / solar mass materials -- concrete, water, wood, brick, adobe. I find that most lists which give the specific heat capacity (joule / gram) are not very helpful because then you have to go look up the density of the material in order to see how much total heat capacity (in Btus) that material will give you by volume. Or is this wrong? So wondering if there is a resource that will tell me directly how many Btus are in 1 cubic ft of water vs concrete vs wood etc? Additionally, as conductivity seems to be a critical factor in a storage material working (determining how much heat it can absorb) is this factored in to any comparisons of materials? Should it be? I would think a plot of materials ranking them by both storage capacity and conductivity would be extremely helpful. But I'm surprised I cannot find one. And lastly -- bonus help! -- I am also particularly interested in the heat capacities of soils as I work with greenhouses mostly. Any resources that list the volumetric heat capacities of different types of soils? I know that is asking a lot.... Thanks so much for your help!! Lindsey
Registered: 1388591029 Posts: 2,826
Reply with quote #2
I think you might be on your own there. I have been looking and while specific heat and specific gravity are easy enough to find, volumetric heat capacity is nowhere to be found.
I'd suggest you plug the first two tables into a spreadsheet which will do the math for you, and save it. Then you can simply look it up any time. __________________ Solar is like the wind. It may be free, but putting it to work isn't! Willie, Tampa Bay
Registered: 1359070732 Posts: 2,240
Reply with quote #3
I am not sure that knowing the volumetric heat capacity will get you anywhere fast...
Presumably you are looking at storing heat, therefore I should have thought that it's the specific heat capacity you ought to be looking out for... By definition, the specific heat capacity should be enough, since it states (for a given substance), the amount of heat needed to raise the temperature of a certain mass of that substance, through 1 degree Celsius. The notion of "specific" already takes into account the bulk density of the substance, so that all the substances in that table are already on a "level playing field" as regards how much heat they can hold... It is like comparing fuel consumption and specific fuel consumption: fuel consumption is OK in certain circumstances, but for more understanding of performance, you need to know the "specific" parameter -- https://www.grc.nasa.gov/www/k-12/airplane/sfc.html So back to heat storage, the "specific" automatically includes the volume-density of the particular substance, in the equation: so you don't really need to be looking for the volumetric parameter - it is already included (all substances having a particular density in any case...) (even if I *am* repeating myself myself). G_H __________________
(1) "Heat goes from hot to cold, there is no directional bias" (2) It's wrote, "voilà" unless talking musical instruments...