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A low-energy house is a guideline rarely specified in actual values (heat load or space-heating minimum). A passive house is a standard, with specific recommendations to save heating energy. At one end of the spectrum are buildings with an ultra-low space-heating requirement which require low levels of imported energy (even in winter ...
BBC Bitesize, [1] also abbreviated to Bitesize, is the BBC's free online study support resource for school-age pupils in the United Kingdom. It is designed to aid pupils in both schoolwork and, for older pupils, exams .
Energy (from Ancient Greek ἐνέργεια (enérgeia) 'activity') is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat and light.
The heating value (or energy value or calorific value) of a substance, usually a fuel or food (see food energy), is the amount of heat released during the combustion of a specified amount of it. The calorific value is the total energy released as heat when a substance undergoes complete combustion with oxygen under standard conditions.
Heating degree day (HDD) is a measurement designed to quantify the demand for energy needed to heat a building. HDD is derived from measurements of outside air temperature . The estimated average heating energy requirements for a given building at a specific location are considered to be directly proportional to the number of HDD at that location.
The molar heat capacity is the heat capacity per unit amount (SI unit: mole) of a pure substance, and the specific heat capacity, often called simply specific heat, is the heat capacity per unit mass of a material. Heat capacity is a physical property of a substance, which means that it depends on the state and properties of the substance under ...
The Btu is often used to express the conversion-efficiency of heat into electrical energy in power plants. Figures are quoted in terms of the quantity of heat in Btu required to generate 1 kW⋅h of electrical energy. A typical coal-fired power plant works at 10,500 Btu/kWh (3.1 kWh/kWh), an efficiency of 32–33%. [25]
Internal energy: The energy contained within a body of matter or radiation, excluding the potential energy of the whole system, and excluding the kinetic energy of the system moving as a whole. Heat : Energy in transfer between a system and its surroundings by mechanisms other than thermodynamic work and transfer of matter.