| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 102 === This study is focused on the performance of Under-Floor Air Distribution (UFAD) system with different thermostat locations in an indoor space having the same heat load condition. Comparing Under-Floor Air Distribution system with
Ceiling-Based Air Distribution (CBAD) system, UFAD system has clearer temperature stratification, and CBAD system has an uniform interior temperature.
There are three series LR(A), LR(B) and LR(C) in experiments, and each series has a different thermostat location. The thermostat is located at Z = -300 mm, 1300 mm and 1700 mm respectively for the series of LR(A), LR(B) and LR(C). Experimental measurements were conducted in the test chamber utilizing the under-floor air distribution system. The UFAD system supplies cool conditioned air from the raised floor to the indoor space and extracts hot polluted
air through return vents on the ceiling. The research measures the
supply air velocity, the air flow rate, the vertical temperature profiles
and estimates the removed heat in the indoor environment.
Experimental results of the individual air flow rates of SA3 and
SA4 diffusers are 0.05 m3/s and 0.03 m3/s for the Q1 option, 0.05 m3/s
and 0.03 m3/s for the Q2 option, 0.08 m3/s and 0.05 m3/s for the
Q3 option. The combination supply air flow rate, i.e. measuring the
two supply diffusers at the same time, is 0.07 m3/s for the Q1 option,
0.08 m3/s for the Q2 option and 0.12 m3/s for the Q3 option.
The results show that the supply air flow rate affects the throw
height and the stratification height significantly, but the thermostatic location has no clear relationship with them. As the supply
air flow rate increases, the throw height rises in all the experimental
series, and the stratification height rises in the series of LR(A) and
LR(C), but it descends in the series of LR(B). The removed heat
of the UFAD system from the floor level to the height of 1.7 m is
more than that of the traditional mixing type system in all the ex-
perimental series. The average values of Ep, the removed heat ratio
of UFAD to CBAD system between 0.1 m and 1.7 m, are 1.44, 1.46
and 1.25 in three series of experiments with the Q1, Q2 and Q3 options respectively for UFAD system. Experimental results show that
the UFAD system provides a better heat removal efficiency for the
bottom occupant region than the traditional mixing type system.
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