Кіріспе
Температура мәндерінің қосындысы. Жылу градус күні (ЖДК) – ғимаратты жылытуға қажетті энергияның сұранысын сандық тұрғыдан бағалауға арналған өлшем. ЖДК сыртқы ауа температурасының өлшемдерінен шығарылады. Белгілі бір орналасқан жердегі ғимараттың жылу қажеттілігі сол жердегі ЖДК санына тура пропорционал болып есептеледі. Бұған байланысты, кондиционерге деген сұранысты сандық тұрғыдан бағалайтын салқындату градус күні (СДК) де бар.
Sum of temperature values
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 heating requirements for a given building at a specific location are considered to be directly proportional to the number of HDD at that location. Related measurements include the cooling degree day (CDD), which quantifies demand for air conditioning.
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 heating requirements for a given building at a specific location are considered to be directly proportional to the number of HDD at that location. Related measurements include the cooling degree day (CDD), which quantifies demand for air conditioning.
Анықтама
Жылыту градус күндері негізгі температураға қатысты анықталады — ғимаратты жылыту қажет емес сыртқы температура. Негізгі температура белгілі бір ғимарат үшін ғимарат қыздырылатын температураға байланысты анықталуы мүмкін, немесе мысалы, ел немесе аймақ үшін анықталуы мүмкін. Соңғы жағдайда температуралық шекті температураға арналған құрылыс стандарттары немесе келісімдер болуы мүмкін. Оларға мыналар жатады:
Heating degree days are defined relative to a base temperature—the outside temperature above which a building needs no heating. Base temperatures may be defined for a particular building as a function of the temperature that the building is heated to, or it may be defined for a country or region for example. In the latter case, building standards or conventions may exist for the temperature threshold. These include:
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Ел/Аймақ | Базалық температура (°C) | Базалық температура (°F)
------- | -------- | --------
Еуропалық Одақ | 15.5 | 59.9
Дания | 17 | 62.6
Финляндия | 17 | 62.6
Швейцария | 12 | 53.6
АҚШ | 18.3 | 65
Heating degree days are defined relative to a base temperature—the outside temperature above which a building needs no heating. Base temperatures may be defined for a particular building as a function of the temperature that the building is heated to, or it may be defined for a country or region for example. In the latter case, building standards or conventions may exist for the temperature threshold. These include:
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Базалық температура міндетті түрде ғимараттың орташа ішкі температурасына сәйкес келуі керек емес, себебі стандарттар ғимараттың орташа жылу оқшаулау деңгейін және ішкі жылуды ескере отырып, жылу қажет болатын орташа сыртқы температураны анықтауы мүмкін. Сондай-ақ, 16 °C және 19 °C (61, 66 °F) базалық температуралар да қолданылады. Базалық температураны таңдаудағы айырмашылықтар HDD мәндерін әрқашан салыстыруға болмайды дегенді білдіреді – тек бірдей базалық температурасы бар HDD-лерді ғана салыстыруға тырысу керек.
Heating degree days are defined relative to a base temperature—the outside temperature above which a building needs no heating. Base temperatures may be defined for a particular building as a function of the temperature that the building is heated to, or it may be defined for a country or region for example. In the latter case, building standards or conventions may exist for the temperature threshold. These include:
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
HDD-ні есептеудің бірнеше тәсілі бар: температуралық деректер неғұрлым толық болса, HDD-ні соғұрлым дәл есептеуге болады. HDD көбінесе күнделікті температуралық көрсеткіштерді пайдаланатын қарапайым шамалау әдістерімен есептеледі, жарты сағаттық көрсеткіштер сияқты толық температуралық деректердің орнына, соңғысы интегралды бағалау үшін қолданылуы мүмкін. АҚШ Ұлттық ауа-райы қызметі қолданатын танымал шамалау әдісі – кез келген күннің орташа температурасын (жоғары және төмен температураның орташасы) алып, оны базалық температурадан шегеру. Егер нәтиже нөлден кем немесе тең болса, сол күні HDD нөлге тең болады. Ал егер нәтиже оң болса, ол сол күнгі HDD санын көрсетеді. (Салқындату градус күндері үшін процесс керісінше жұмыс істейді: базалық температура орташадан шегеріледі, егер нәтиже оң болса, ол CDD санын көрсетеді.) Бұл әдіс сыртқы ауа температурасы базалық температурадан аспаса қанағаттанарлық жұмыс істейді. Бұл жағдай кез келген уақытта орын алуы мүмкін климаттарда қарапайым есептеуге кейбір «түзетутер» енгізіледі, бұл ауа жылыту қажет емес болған кезде күннің бөлігін ескереді. Бұл дәл алгоритм жыл бойы (тек бір жылыту маусымында емес) және апталық, сондай-ақ айлық негізде орташа климаттық (теңіздік және континенттік) жағдайларда нәтижелерді есептеуге мүмкіндік береді. HDD-ні белгілі бір кезеңде қосу арқылы маусымдық жылу қажеттілігін шамамен бағалауға болады. Мысалы, жылыту маусымында Нью-Йорк қаласы үшін HDD саны 5050 болса, Аляскадағы Утқиагвик үшін 19 990-ды құрайды. Осылайша, ұқсас құрылымы мен жылу оқшаулауы бар үй үшін, Утқиагвиктегі үйді жылыту үшін Нью-Йорктегіден шамамен төрт есе көп энергия қажет болады. Сол сияқты, Майамидегі (Флорида штаты) ұқсас үй, жылыту маусымында 500 жылыту градус күніне ие болса, Нью-Йорктегі үйді жылыту үшін қажетті энергияның оннан бір бөлігін қажет етеді.
Heating degree days are defined relative to a base temperature—the outside temperature above which a building needs no heating. Base temperatures may be defined for a particular building as a function of the temperature that the building is heated to, or it may be defined for a country or region for example. In the latter case, building standards or conventions may exist for the temperature threshold. These include:
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Дегенмен, бұл теориялық тәсіл, өйткені ғимараттың жылу оқшаулау деңгейі жылуға деген сұранысқа әсер етеді. Мысалы, температура түнде көбінесе базалық температурадан төмен түседі (тәуліктік өзгерістегі ең төмен температура), бірақ жылу оқшаулаудың арқасында жылыту қажет емес. Көктемнің соңында және күздің басында немесе климатқа байланысты қыста жеткілікті жылу оқшаулау ішкі температураны сыртқы температурадан жоғары ұстайды, жылудың қажеті болмайды. Мысалы, Оңтүстік Калифорнияда, егер жылу оқшаулау түнгі салқын температураны ескере алатын болса, Лос-Анджелес және Сан-Диегода қысқы жылыту қажет емес. Сонымен қатар, ғимараттарға бетон сияқты жылу массасы кіреді, ол күндіз сіңірілген күн энергиясын сақтай алады. Осылайша, тіпті жылыту градус күндері жылыту қажеттілігін көрсетсе де, ғимараттың жеткілікті жылу оқшаулауы жылытуды қажетсіз ете алады.
Heating degree days are defined relative to a base temperature—the outside temperature above which a building needs no heating. Base temperatures may be defined for a particular building as a function of the temperature that the building is heated to, or it may be defined for a country or region for example. In the latter case, building standards or conventions may exist for the temperature threshold. These include:
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Country/RegionBase Temperature (°C)Base Temperature (°F)European Union15.559.9Denmark, 1762.6Finland1762.6Switzerland1253.6United States18.365
The base temperature does not necessarily correspond to the building mean internal temperature, as standards may consider mean building insulation levels and internal gains to determine an average external temperature at which heating will be required. Base temperatures of 16 °C and 19 °C (61, 66 °F) are also used. The variation in choice of base temperature implies that HDD values cannot always be compared – care must be taken to ensure that only HDDs with equal base temperatures are compared. There are a number of ways in which HDD can be calculated: the more detailed a record of temperature data, the more accurate the HDD that can be calculated. HDD are often calculated using simple approximation methods that use daily temperature readings instead of more detailed temperature records such as half hourly readings, the latter of which can be used to estimate an integral. One popular approximation method, that used by the U. S. National Weather Service, is to take the average temperature on any given day (the mean of the high and low temperature) and subtract it from the base temperature. If the value is less than or equal to zero, that day has zero HDD. But if the value is positive, that number represents the number of HDD on that day. (For cooling degree days, the process works in reverse: the base temperature is subtracted from the average, and if this value is positive, that number represents the CDD.) This method works satisfactorily if the outside air temperature does not exceed the base temperature. In climates where this is likely to occur from time to time, there are refinements to the simple calculation which allow some 'credit' for the period of the day when the air is warm enough for heating to be unnecessary. This more accurate algorithm enables results to be computed in temperate climates (maritime as well as continental) throughout the year (not just during a defined heating season) and on a weekly as well as monthly basis. HDD can be added over periods of time to provide a rough estimate of seasonal heating requirements. In the course of a heating season, for example, the number of HDD for New York City is 5,050 whereas that for Utqiagvik, Alaska is 19,990. Thus, one can say that, for a given home of similar structure and insulation, around four times the energy would be required to heat the home in Utqiagvik than in New York. Likewise, a similar home in Miami, Florida, whose heating degree days for the heating season is 500, would require around one tenth of the energy required to heat the house in New York City. However, this is a theoretical approach as the level of insulation of a building affects the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary. In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating. For example, in southern California, during winter heating is not necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Қиындықтар
ҚТҚ-ны қолдану есептеуінде бірнеше мәселелер бар. Жылу қажеттіліктері температураға тура пропорционал емес, ал жақсы жылу оқшауланған ғимараттардың "тепе-теңдік температурасы" төмен болады. Қажетті жылу және салқындату мөлшері сыртқы температурадан өзге де бірнеше факторларға байланысты: нақты ғимараттың жылу оқшаулау деңгейі, үйдің ішіне түсетін күн сәулесінің мөлшері, қосылған электр құралдарының саны (мысалы, компьютерлер айналасындағы температураны көтереді), сырттағы желдің күші және тұрғындардың қандай температураны қолайлы деп санайтыны. Тағы бір маңызды фактор – үй ішіндегі салыстырмалы ылғалдылық деңгейі; бұл адамның жайлы болуын анықтау үшін маңызды. Жауын-шашын, бұлттылық, жылу индексі, ғимараттың альбедосы және қар жамылғысы сияқты басқа да айнымалылар ғимараттың жылулық жауабын өзгерте алады. ҚТҚ-ның тағы бір кемшілігі – оларды халықаралық деңгейде климаттарды салыстыру үшін пайдаланғанда сақтық тану қажет, себебі әртүрлі елдерде стандарт ретінде әртүрлі базалық температуралар қолданылады, сондай-ақ АҚШ-та Фаренгейт шкаласы, ал әлемнің көп бөлігінде Цельсия шкаласы қолданылады. Бұл әртүрлі елдерде қолданылатын әртүрлі жуықтау әдістерімен күшейеді.
Calculations using HDD have several problems. Heat requirements are not linear with temperature, and heavily insulated buildings have a lower "balance point". The amount of heating and cooling required depends on several factors besides outdoor temperature: How well insulated a particular building is, the amount of solar radiation reaching the interior of a house, the number of electrical appliances running (e. g. computers raise their surrounding temperature) the amount of wind outside, and what temperature the occupants find comfortable. Another important factor is the amount of relative humidity indoors; this is important in determining how comfortable an individual will be. Other variables such as precipitation, cloud cover, heat index, building albedo, and snow cover can also alter a building's thermal response. Another problem with HDD is that care needs to be taken if they are to be used to compare climates internationally, because of the different baseline temperatures used as standard in different countries and the use of the Fahrenheit scale in the US and the Celsius scale almost everywhere else. This is further compounded by the use of different approximation methods in different countries.