scholarly journals An Experimental Study on Operating Characteristic of Radiant Floor Cooling Integrated with Underfloor Ventilation System

2021 ◽  
Vol 39 (4) ◽  
pp. 1207-1212
Author(s):  
Ning Cai ◽  
Dongliang Zhang
Keyword(s):  
Experimental Study ◽  
Air Temperature ◽  
Cooling System ◽  
Ventilation System ◽  
Average Water Temperature ◽  
System Parameters ◽  
Value Range ◽  
Heat Quantity ◽  
Average Water ◽  
Radiant Floor Cooling System

In this paper, an experimental study on radiant floor cooling integrated with underfloor ventilation (RFCUV) system was conducted. Indoor environment temperatures, radiant floor cooling system parameters and underfloor ventilation system parameters were measured. Humane thermal comfort was analyzed experimentally. And the effects of disturbance variables and manipulated variables on controlled variables were analyzed. The results illustrated that operative temperature (OT), predicted mean vote (PMV) and predicted percent dissatisfied (PPD) decrease in the first two hours and then become stable in ISO7730 recommended value range. IAT and OT increase with the increasing of the disturbance variables and manipulated variables. The increasing ratio of indoor air temperature (IAT) and OT are relatively small when comprehensive outdoor air temperature is relatively high and indoor heat quantity or average water temperature is relatively low. IAT and OT increase approximately linearly with the increasing of supply air temperature.

scholarly journals Experimental investigation of occupants’ thermal sensation under a personalized ventilation system

2021 ◽  
Vol 2069 (1) ◽  
pp. 012167
Author(s):  
P Ebrahimi Naghani ◽  
S A Zolfaghari ◽  
M Maerefat ◽  
J Toftum ◽  
S M Hooshmand ◽  
...  
Keyword(s):  
Air Temperature ◽  
Cooling System ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Body Part ◽  
Whole Body ◽  
Energy Costs ◽  
Air Temperatures ◽  
The Common ◽  
Personalized Ventilation

Abstract By considering the importance of providing proper indoor environment conditions for occupants and also due to energy costs, one of the solutions for indoor local air-conditioning is Personalized Ventilation System (PVS). In this paper, the occupants’ thermal sensation was experimentally studied for body segments that are mostly affected by the PVS. The local sensation of head, chest, arm, and hand at two supply air temperatures of 16 and 32°C were investigated. Eight volunteer subjects participated in this survey. The subjects reported the most thermal satisfaction on their hands. Also, the arms were the segments with the coolest thermal sensation (-1.28, between slightly cool and cold). Results indicate that the head’s thermal sensation at both supply air temperatures was neutral and the hand was the only body part that experienced warm thermal sensation during the test. Also, by increasing the supply air temperature to 32°C whole body thermal sensation changed from -0.46 to -0.09 on the seven-point scale, which means that the cooling system worked properly for occupants’ cooling. In this system, cooling occurred at 32°C instead of the common 16°C supply air temperature, which results in energy-saving and decreases annual running costs.

scholarly journals RESULTS OF INSPECTION OF THE STATE OF PROVIDING THE MICROCLIMATE IN THE PIG FARM WITH A NEGATIVE PRESSURE VENTILATION SYSTEM

2021 ◽  
pp. 168-177
Author(s):  
Vitalii Yaropud ◽  
Yelchin Aliyev
Keyword(s):  
Air Temperature ◽  
Negative Pressure ◽  
Cooling System ◽  
Ventilation System ◽  
Air Cooling ◽  
Negative Pressure Ventilation ◽  
Normal Limits ◽  
Air Supply ◽  
Air Cooling System ◽  
Pig Farm

The most popular microclimate system today is based on a negative pressure ventilation system. Because it is easier to use and consumes less energy than any other forced ventilation system. The purpose of the research is to inspect the room for keeping piglets on rearing with a negative pressure ventilation system to identify shortcomings and deviations of the microclimate parameters necessary for further improvement. According to the results of the inspection of the rearing room for piglets, it was found that according to the existing system of negative pressure in the rearing room for piglets, most indicators (air velocity, ammonia, carbon dioxide, hydrogen sulfide, oxygen) are within normal limits. According to the results of the inspection of the room for keeping piglets for rearing with a negative pressure microclimate system, it was found that the air temperature in the room does not meet the recommended limits and reaches 30 °C, while the maximum recommended temperature for piglets for fattening is 20 °C. The air temperature is uneven along the length of the room, which is caused by uneven air supply from the vents. According to the results of the inspection of the room for piglets with a negative pressure microclimate system, it was found that the relative humidity at the height of the animals is higher than the recommended norms and reaches 95%, while the recommended humidity for piglets for fattening is not more than 80%. According to the results of the inspection of the room for keeping piglets for rearing with a negative pressure microclimate system, it can be stated that it is necessary to improve the air cooling system and replan the ventilation ducts of the ventilation system to ensure even air flow.

Influence of sensible cooling load on indoor air distribution in an office room with ceiling cooling and mixing ventilation

2020 ◽  
pp. 1420326X2092481
Author(s):  
Xiaozhou Wu ◽  
Haichao Wang ◽  
Jie Gao ◽  
Fenghao Wang
Keyword(s):  
Air Temperature ◽  
Temperature Difference ◽  
Turbulence Intensity ◽  
Indoor Air ◽  
Cooling System ◽  
Ventilation System ◽  
Air Distribution ◽  
Cooling Load ◽  
Contaminant Removal ◽  
Vertical Distributions

A mixing ventilation system integrated with a ceiling cooling system is a potential advanced heating, ventilation and air conditioning system for modern office buildings with a high sensible cooling load. This paper presents an evaluation of the effect of sensible cooling load on the indoor air distribution in a typical office room with mixing ventilation and ceiling cooling. The vertical distributions of indoor air temperature, air velocity and contaminant (CO2) concentration were evaluated by the vertical air temperature difference, turbulence intensity and contaminant removal effectiveness. The results showed that when the chilled ceiling surface temperature was increased from 15.0°C to 23.0°C and supply air temperature was decreased from 22.0°C to 19.0°C, the average vertical air temperature difference, turbulence intensity and contaminant removal effectiveness were 0.2°C–0.3°C, 27%–32% and 0.53–0.81 as both internal and external sensible cooling loads were 41.5 W/m2. Moreover, these evaluation indices varied slightly as the external sensible cooling load was increased from 41.5 W/m2 to 69.5 W/m2, whereas they varied greatly as the internal sensible cooling load was increased from 41.5 W/m2 to 69.5 W/m2. Hence, the external sensible cooling load could slightly affect the indoor air distribution, whereas the internal sensible cooling load could clearly affect the indoor air distribution in an office room with mixing ventilation and ceiling cooling.

Numerical and experimental study on the effect of nozzle position and inlet air temperature in an industrial-type biomass gasifier

2021 ◽  
Author(s):  
Murugan Paradesi Chockalingam ◽  
Saji Raveendran Padmavathy ◽  
Sree Nithyanandan ◽  
Godwin Glivin ◽  
Beno Wincy Winsly Roy ◽  
...  
Keyword(s):  
Experimental Study ◽  
Air Temperature ◽  
Nozzle Position

An Experimental Study of Adsorption Cooling System by Using Low Grade Heat Source

2018 ◽  
Author(s):  
H. M. Elgohary ◽  
H. M. Soliman ◽  
A. M. Soliman ◽  
H. H. Gouda ◽  
S.P. Chowdhury
Keyword(s):  
Experimental Study ◽  
Heat Source ◽  
Cooling System ◽  
Low Grade ◽  
Adsorption Cooling System ◽  
Low Grade Heat

Thermal Model of a Thinned-Die Cooling System

2003 ◽  
Author(s):  
N. Boiadjieva ◽  
P. Koev
Keyword(s):  
Experimental Data ◽  
Thermal Model ◽  
Cooling System ◽  
Input Power ◽  
The Other ◽  
System Parameters ◽  
Air Intake ◽  
Optical Probing ◽  
Cooling Air ◽  
Better Than

For through-silicon optical probing of microprocessors, the heat generated by devices with power over 100W must be dissipated [1]. To accommodate optical probing, a seemingly elaborate cooling system that controls the microprocessor temperature from 60 to 100° C for device power up to 150W was designed [2]. The system parameters to achieve the desired thermal debug environment were cooling air temperature and air flow. A mathematical model was developed to determine both device temperature and input power. The 3-D heat equation that governs the temperature distribution was simplified to a case of a 1-D rod with one end at the device center and the other at the cooling air intake. Thus the cooling system was reduced to an analytical expression. From experimental data, we computed all coefficients in the model, then ran extensive tests to verify—the accuracy was better than 10% over the entire temperature and power ranges.

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