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Energy efficiency and indoor thermal perception: a comparative study between radiant panel and portable convective heaters

Energy Efficiency volume 3, pages 283–301 (2010)Cite this article

Abstract

This study investigates experimentally the thermal perception of indoor environment for evaluating the ability of radiant panel heaters to produce thermal comfort for space occupants as well as the energy consumption in comparison with conventional portable natural convective heaters. The thermal perception results show that, compared with conventional convection heater, a radiantly heated office room maintains a lower ambient air temperature while providing equal levels of thermal perception on the thermal dummy head as the convective heater and saves up to 39.1% of the energy consumption per day. However, for human subjects’ vote experiments, the results show that for an environmentally controlled test room at outdoor environment temperatures of 0°C and 5°C, using two radiant panel heaters with a total capacity of 580 W leads to a better comfort sensation than the conventional portable natural convective heater with a 670 W capacity, with an energy saving of about 13.4%. In addition, for an outdoor environment temperature of 10°C, using one radiant panel heater with a capacity of 290 W leads to a better comfort sensation than the conventional convection heater with a 670 W capacity, with an energy saving of about 56.7%. From the analytical results, it is found that distributing the radiant panel heater inside the office room, one on the wall facing the window and the other on the wall close to the window, provides the best operative temperature distribution within the room.

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Abbreviations

A :

surface area, m2

c p :

specific heat, J/kg K

F :

radiation configuration (shape) factor

h :

heat transfer coefficient, W/m2 K

H :

room height, m

\({\dot m}\) :

mass flow rate, kg/s

N :

number of surface elements number, -

q :

heat flux, W/m2

Q :

heat transfer, W

R th :

thermal resistance, m2 K/ W

T :

temperature, K or °C

X :

axial horizontal distance, m, -

y :

axial vertical distance, m, -

Z :

axial distance, m, -

ε :

emittance

ρ :

reflectance

σ :

Stefan–Boltzmann constant, (5.67051 × 10-8), W/m2 K4

a:

air

cnd:

conduction

cnv:

convection

i:

element i

if:

infiltration

j:

element j

o:

operative temperature

outd:

outdoor

rad:

radiation

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Authors and Affiliations

  1. Department of Mechanical Engineering, Faculty of Engineering, Assiut University, Assiut, 71516, Egypt

    Ahmed Hamza H. Ali & Mahmoud Gaber Morsy

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  1. Ahmed Hamza H. Ali
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  2. Mahmoud Gaber Morsy
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Correspondence to Ahmed Hamza H. Ali.

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Ali, A.H.H., Gaber Morsy, M. Energy efficiency and indoor thermal perception: a comparative study between radiant panel and portable convective heaters. Energy Efficiency 3, 283–301 (2010). https://doi.org/10.1007/s12053-010-9077-3

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  • DOI: https://doi.org/10.1007/s12053-010-9077-3

Keywords

  • Energy efficiency
  • Radiant panel heater
  • Conventional natural convective heater
  • Indoor environment thermal perception
  • Energy saving