Experimental investigation of heat transfer coefficients between hydronic radiant heated wall and room

• Experiments conducted for different wall panel arrangements and flow temperatures.
• Radiant and convective heat transfer coefficients were 5.7 and 2.7 W m−2 K−1.
• Total heat transfer coefficient was found as follows: qtotal = 8.7(Top − Ts).
• Different arrangements affect the convective heat transfer coefficient in nearly 25%.
• Different arrangements do not affect the radiant heat transfer coefficient very much.

The reason radiant heating systems are highly preferred in recently designed or a modernized construction is due to their energy efficiency and low exergy destruction. Radiant heating systems are different from typical HVAC systems because they heat surfaces rather than air and can save large amounts of energy while providing higher levels of comfort.The fundamental design parameters for a radiant heating system are heat transfer coefficients such as radiation, convection and total heat transfer coefficients. In this study, the values of radiant, convective and total heat transfer coefficients were calculated based on the experimental results that were taken from the climatic test chamber.This article presents the results based on an experimental research on heated radiant hydronic wall panels mounted in the climatic test chamber. The aim was to estimate the values of heat transfer coefficients for different location configurations of radiant wall heating panels experimentally. This experimental study was conducted under the location configurations of 3 different wall panel arrangements for 7 water flow temperatures ranging from 30 °C to 42 °C.It was noticed that the amount of radiation heat transfer increased when the crosswise area of the window surface was heated and simultaneously the heat transfer capability of radiation rose by 70% of the total heat transfer.