Rock (geology) arkoses (12%). Sedimentary rocks often contain fossils. Sedimentary rocks form under the influence of gravity and typically are deposited in horizontal or near horizontal layers or strata and may be referred to as stratified rocks. A small fraction of sedimentary rocks deposited on steep slopes will show cross bedding where one layer stops abruptly along an interface where another layer eroded the first as it was laid atop the first. Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure conditions than those in which the original rock was
Heat recovery ventilation heat which is coming from inside environment. Heat recovery system basically works as transferring the thermal energy (enthalpy) from one fluid to another fluid, from one fluid to one solid or from a solid surface to a fluid, at different temperatures and in thermal contact. Additionally, there is no direct interaction between fluid and fluid or fluid and solid in most of the heat recovery systems. In some application of heat recovery systems, fluid leakage is observed due to pressure differences and that causes mixture of two fluids. Rotary thermal wheels are a mechanical means of heat recovery. A rotating