Radiator and floor heating operative temperature and temperature variation corrections for EN 15316-2 heat emission standard

Maivel, Mikk; Kurnitski, Jarek

doi:10.1016/j.enbuild.2015.04.021

Cited by 18 publications

(10 citation statements)

References 8 publications

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“…The reason is that the above functions are not linear in a, b, c: since the view factors are additive, a more correct way to calculate them with formulas (A1) and (A2) consists of subtracting F p−A i at a = h from F p−A i at a = h + 15cm. This way one obtains a net view factor, which despite not being 100% accurate, returns physical operative temperatures that match earlier results [24,36] and the present numerical simulations (see e.g. Figs.…”

Section: Discussionsupporting

confidence: 88%

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Optimization of Radiators, Underfloor and Ceiling Heater Towards the Definition of a Reference Ideal Heater for Energy Efficient Buildings

Ferrantelli¹,

Võsa²,

Kurnitski³

2018

Preprint

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Heat emitters constitute the primary devices used in space heating and cover a fundamental role in the energy efficient use of buildings. In the search for an optimized design, heating devices should be compared with a benchmark emitter with maximum heat emission efficiency. However, such an ideal heater still needs to be defined. In this paper we perform an analysis of heat transfer in a European reference room, considering room side effects of thermal radiation and computing the induced operative temperature both analytically and numerically. By means of functional optimization, we analyse trends such as the variation of operative temperature with radiator panel dimensions, finding optimal configurations. In order to make our definitions as general as possible, we address panel radiators, convectors, underfloor (UFH) and ceiling heater. We obtain analytical formulas for the operative temperature induced by panel radiators and identify the 10-type as our ideal radiator, while the UFH provides the best performance overall. Regarding specifically UFH and ceiling heaters, we find optimal sizes that identify the according ideal emitters. The analytical method and quantitative results reported in this paper can be generalized and adopted in most studies concerning the efficiency of different heat emitter types in building enclosures.

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Section: Discussionsupporting

confidence: 88%

“…in [36] that the energy demand is very sensitive to operative temperature corrections. In particular, a difference of only 0.1°C can increase the annual heating need by 1-2% [36]: such effect is found for both the convector and the 21-type panel radiator, which are therefore fairly underperforming.…”

Section: Figure 22mentioning

confidence: 99%

Optimization of Radiators, Underfloor and Ceiling Heater Towards the Definition of a Reference Ideal Heater for Energy Efficient Buildings

Ferrantelli¹,

Võsa²,

Kurnitski³

2018

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…The reason is that the above functions are not linear in a, b, c: since the view factors are additive, a more correct way to calculate them with formulas (A1) and (A2) consists of subtracting F p−A i at a = h from F p−A i at a = h + 15cm. This way one obtains a net view factor, which despite not being 100% accurate, returns physical operative temperatures that match earlier results [20,24] and the present numerical simulations (see e.g. Figs.…”

Section: Appendix View Factors and Operative Temperature Formulassupporting

confidence: 88%

“…approaches the air temperature is very advantageous for energy saving, as it was shown e.g. in [24] that the energy demand is very sensitive to operative temperature corrections. In particular, a difference of only 0.1°C is capable of inducing an increase of the annual heating need by 1-2% [24]: such effect is found for the convector and 21-type panel radiator, which are therefore fairly underperforming.…”

Section: Figure 20mentioning

confidence: 99%

Optimization of Radiators, Underfloor and Ceiling Heating towards the Definition of a Reference Ideal Heater for Energy Efficient Buildings

Ferrantelli¹,

Võsa²,

Kurnitski³

2018

Preprint

Self Cite

View full text Add to dashboard Cite

Heat emitters constitute the primary devices used in space heating and cover a fundamental role in the energy efficient use of buildings. In the search for an optimized design, heating devices should be compared with a benchmark emitter with maximum heat emission efficiency. However, such an ideal heater still needs to be defined. In this paper we perform an analysis of heat transfer in a European reference room, considering room side effects of thermal radiation and computing the induced operative temperature both analytically and numerically. By means of functional optimization, we analyse trends such as the variation of operative temperature with radiator panel dimensions, finding optimal configurations. In order to make our definitions as general as possible, we address panel radiators, convectors, underfloor (UFH) and ceiling heating. We obtain analytical formulas for the operative temperature induced by panel radiators and identify the 10-type as our ideal radiator, while the UFH provides the best performance overall. Regarding specifically UFH and ceiling heaters, we find optimal sizes that identify the according ideal emitters. The analytical method and quantitative results reported in this paper can be generalized and adopted in most studies concerning the efficiency of different heat emitter types in building enclosures.

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“…In [23] authors proved that low temperature heating systems result in better thermal comfort compared to the other available on the market. Authors in [24] state that using the operative temperature, as it is not yet implemented in the prEN ISO 15316-2:2014 methodology for calculation of losses generated by heating and domestic hot water production, instead of the air temperature will create a difference in losses incurred in the generation subsystem.…”

Section: Introductionmentioning

confidence: 99%

Study of Operative Temperature Using the Novel Detail Approach in Determining Mean Radiant Temperature – Comparison Between Wall-Mounted Convector and Conventional Radiator

Tomorad

Horvat

Dović

2018

TFAMENA

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SummaryMost of the physical parameters that are used to assess the satisfaction with the ambient thermal condition in a mathematical way are contained within the definition of operative temperature. This temperature, which can be used as a representative of indoor thermal comfort, is a function of the air temperature, the mean radiant temperature and the relative air velocity.In this paper, the room air, mean radian temperature and indoor air velocity were determined experimentally for wall-mounted convector and conventional radiator at controlled room conditions. The room air temperature and indoor air velocity were continuously measured at several positions and heights (0.75 m and 1.5 m) using calibrated T-type thermocouples and hot wire probes, while mean radiant temperature was calculated using the thermograms captured by the IR thermal camera and numerically computed radiation view factors. Each wall was divided into several sections with approximately similar temperatures (differences < 0.5 °C) for which view factors were determined. Thermal heat output of the tested heat emitters was derived according to EN 442-2:2014. Obtained results were analysed and conclusions about the achieved thermal comfort and related energy saving were made accordingly. Key words:Mean radiant temperature, operative temperature, thermal comfort, thermography, heat emitters IntroductionEuropean and national regulations based on EPBD (Energy Performance of Buildings Directive) seek to decrease energy consumption in buildings, without decreasing the thermal comfort, to achieve goals which include emission control and reduction of primary energy consumption. Prevision and assessment of energy consumption in households are essential items in achieving these goals. Heating, ventilation and air conditioning systems (HVAC) account for over 60% of total energy consumption in buildings [1]. High energy consumption of traditional HVAC systems is based on the aspirations to achieve and maintain uniform air temperature in rooms, preferably at an interval of 2°C [2]. However, recent research has shown that the overall satisfaction with thermal comfort was accomplished in only 11% of buildings [2].

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Radiator and floor heating operative temperature and temperature variation corrections for EN 15316-2 heat emission standard

Cited by 18 publications

References 8 publications

Optimization of Radiators, Underfloor and Ceiling Heater Towards the Definition of a Reference Ideal Heater for Energy Efficient Buildings

Optimization of Radiators, Underfloor and Ceiling Heater Towards the Definition of a Reference Ideal Heater for Energy Efficient Buildings

Optimization of Radiators, Underfloor and Ceiling Heating towards the Definition of a Reference Ideal Heater for Energy Efficient Buildings

Study of Operative Temperature Using the Novel Detail Approach in Determining Mean Radiant Temperature – Comparison Between Wall-Mounted Convector and Conventional Radiator

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