Note, the Air Specific Heat is reported as kJ/kg-deC, thus the value must be converted to Joules by mulitplying by a factor of 1000. At "standard air" conditions and at sea level, these properties result in the value 1210. At this temperature, a gallon of water weighs around 8.345 lbs. Water has a maximum density of 39.2✯ or 4✬. This is equal to a rounded value of 1 gram per milliliter (g/ml) or 1 gram per cubic centimeter (g/cm 3) or 1000 kg/m 3. The specific heat for dry air (at sea level) is 1008 J/kgK. The density of water at 4 degrees Celsius is 8.345 lbs/U.S. The 2013 ASHRAE Handbook of Fundamentals (page 18.13) states that this condition is represented by either saturated air at 16C dry bulb or dry air at 21C dry bulb. "Standard air" has historically been defined by ASHRAE as having a density of 1.2 kg/cu m. It is actually the product of the density and specific heat of the air. However, the 1210 in this equation is not a constant. 0734 * 60 = 1.0838244 btu/(hr-cfm-F)ġ210 represents the density-specific heat product at standard air and sea-levelĭelta T is the temperature difference in degrees K or C density of water is equal to 1 000 kg/m at 25C (77F or 298.15K) at. In the example above, the density-specific heat product is as follows -Ġ.2461 *. Water weighs 1 gram per cubic centimeter or 1 000 kilogram per cubic meter, i.e. Interpolating for 69F, this results in a specific heat of 0.241 Btu/lbF.Īt "standard air" conditions and at sea level, these properties (density = 0.075 lb/cu ft and specific heat = 0.241 Btu/lbF) result in the value 1.085.Ġ.075 x 0.241 x 60 min/hr = 1.085 Btu/(hr-cfm-F)Īir at other conditions and other elevations will cause this factor to change.īecause TRACE 3D PLUS accounts for elevation in the reported specific heat and density, the values can be used to determine the factor directly.įrom the Psychrometric State Point Report in TRACE 3D Plus. One liter of water at room temperature (70F / 21C) weighs approximately 1 kilogram (35.2 ounces or 2.2lb). The specific heat for dry air (at sea level) is 0.2402 Btu/lbF at -100F and 0.242 Btu/lbF at 250F. The 2013 ASHRAE Handbook of Fundamentals (page 18.13) states that this condition is represented by either saturated air at 60F dry bulb or dry air at 69F dry bulb. "Standard air" has historically been defined by ASHRAE as having a density of 0.075 lb/cu ft. Water - Density, Specific Weight and Thermal Expansion Coefficients Definitions, online calculator and figures and tables with water properties like density, specific weight and thermal expansion coefficient of liquid water at temperatures ranging 0 to 360C (32 to 680F). It is actually the product of the density of the air, the specific heat of the air, and the conversion factor of 60 minutes per hour. The density specific heat product is not a constant. The sensible heat equation is as follows:ĭelta T is the temperature difference in degrees F To determine the density-specific heat product for use with the sensible heat equation, the values from the Design Pscyhrometric State Points report in TRACE 3D Plus can be used.
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