Evaluating the low exergy of chilled water in a radiant cooling system

Wang, Suya; Morimoto, Megumi; Soeda, Haruo; Yamashita, Tatsuya

doi:10.1016/j.enbuild.2008.04.010

Cited by 19 publications

(11 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The impacts of airconditioning parameters on the exergies of chilled water have been demonstrated by Wang et al [59]. This research shows reductions in cooling rates from 100% to 57% and Downloaded by [University of Connecticut] at 12:57 11 April 2015 International Journal of Sustainable Building Technology and Urban Development 100% to 27%, and produces a decrease in the exergy of chilled water by 47% and 67% respectively [59]. Combined air ventilation hydronics emerges as a highly promising field for low energy radiation.…”

Section: Water and Air For Low Exergymentioning

confidence: 93%

“…Exergy analysis supports determining if a system has energy losses due to irreversibility. The evaluation of exergy works, therefore, as a supplement to energy balance analysis is used to indicate possibility of improvements [58,59]. With this purpose, simulation analysis is being implemented to determine if ventilation assisted hydronics is more effective than typical floor water radiation systems.…”

Section: Water and Air For Low Exergymentioning

confidence: 99%

See 1 more Smart Citation

Water and sunlight: regenerative hydronics

Gutierrez

2013

International Journal of Sustainable Building Technology and Ur

View full text Add to dashboard Cite

Hydronic technologies are undergoing significant transformations in an attempt to revolutionise resource independence in buildings. On-site energy generation and waste regeneration are at the centre of this potential paradigm shift. This text initially discusses recent developments in hydronics systems regarding energy source, materiality, distribution and location in buildings, and plenum typology. Secondly, it evaluates emerging innovation in water-based radiation geared particularly toward zero net energy buildings. Lastly, the text presents current research in hydronic technology in which water heating and disinfection are fully integrated into a facade system through microoptics integration. This discussion contributes to the evaluation of incorporating microoptics into future building technologies in which water, waste, and energy are synergistically balanced. The integration of microoptics can fuel radical innovation leaps in this front enabling regenerative hydronics.

show abstract

Section: Water and Air For Low Exergymentioning

confidence: 93%

Section: Water and Air For Low Exergymentioning

confidence: 99%

Water and sunlight: regenerative hydronics

Gutierrez

2013

International Journal of Sustainable Building Technology and Ur

View full text Add to dashboard Cite

show abstract

“…The radiant cooling system uses a heat transfer fluid, normally water, to exchange heat mainly by radiation and convection within the conditioned space [4][5][6]. Compared to all-air systems, radiant cooling systems have the following advantages: (1) reducing the indoor vertical temperature gradient, thereby gradient, thereby increasing the thermal comfort [7]; (2) reducing the discomfort caused by draft, due to the smaller air supply volume required [8,9]; (3) reducing system energy consumption because of the reduced sensing temperature of the human body [5,10]; (4) reducing transport energy consumption because of less air supply volume [11][12][13][14]; (5) reducing energy consumption of cooling transport because water with a much higher thermal capacity than air is used for energy delivery [5]; (6) a higher supply temperature of chilled water for radiant cooling systems increases the heat pump or chiller's efficiency, which leads to a significant reduction in primary energy consumption [15,16]; (7) higher supply temperature of chilled water allows the possible use of renewable energy sources such as ground source heat pumps, free cooling, ground source heat exchangers, and aquifers [17,18]; and (8) the noise caused by high air velocity is decreased because of the sizes of ducts, due to the reduction of the air supply volume [19].…”

Section: Introductionmentioning

confidence: 99%

Thermal Response Characteristics of Intermittently Cooled Room with Tube-Embedded Cooling Slab and Optimization of Intermittent Control

Sui

Wang

et al. 2020

Energies

View full text Add to dashboard Cite

The heat storage effect of the tube-embedded slab cooling system (TESCS) makes the intermittent operation feasible, a reasonable intermittent strategy can fully realize the energy saving effect. This paper purposes to optimize the intermittent control schemes for TESCS by simulation. The response of the thermal environment intermittently cooled by TESCS is firstly studied. Then, the intermittent control schemes of TESCS are studied. On the basis of the dual-objective optimization for thermal comfort and energy efficiency, the optimal scheme is established. The results show that the tube-embedded slab has significant heat storage and release characteristics under intermittent cooling condition. Its maximum cooling capacity appears about one hour after the stop of cooling. Reducing the cooling duration can reduce the system energy consumption, but increasing the cooling duration can reduce the system peak load. Twenty-four-hour cooling can reduce the peak load by about 70%, 67%, and 41%, respectively, compared with 6-h, 8-h, and 12-h cooling. The effect of the cooling duration on the thermal comfort and energy efficiency is much greater than the cooling time distribution. Frequent starts and stops of the pump can increase the cooling capacity obtained by the room to a certain extent. Daytime cooling provides higher comfort and energy efficiency while night cooling can reduce the chiller’s peak cooling requirement by about 25%.

show abstract

“…Compared with conventional all-air systems, radiant cooling systems exhibit the superiority of thermal comfort and energy saving potential. The advantages of this system are as follows: 5–10 (1) reducing indoor vertical temperature gradient, almost no air flow, avoiding local discomfort; (2) decrease in air supply volume reduces cooling feeling due to cold air, and thus reduces the discomfort caused by draft; (3) reduction in air supply volume minimizes air transport energy consumption; (4) employing water to eliminate heat load instead of air greatly reduces energy consumption of cooling transport; (5) radiant cooling reduces the sensing temperature of human body and accordingly reduces system energy consumption; (6) high temperature of chilled water allows the use of natural resources and natural cooling in some seasons; (7) reducing indoor noise.…”

Section: Introductionmentioning

confidence: 99%

Analysis on combinations of indoor thermal microclimate parameters in radiant cooled residential buildings and drawing of new thermal comfort charts

Sui

Zhang

2015

Building Services Engineering Research and Technology

View full text Add to dashboard Cite

This paper proposed to discuss some issues about indoor microclimate parameters design in radiant cooled residential buildings. Based on the thermal comfort model, the relationships between low mean radiant temperature and other thermal microclimate parameters such as indoor air temperature, air velocity, and relative humidity were analyzed. The improved and reasonable combinations of four thermal microclimate parameters including radiant cooling surface temperature, air temperature, air velocity, and relative humidity were further derived. Furthermore, a number of new thermal comfort charts using radiant cooling surface temperature and air temperature as dominant parameters were drawn. The results show that the air temperature can be increased 1–3℃ within the recommended thermal comfort range when the mean radiant temperature is reduced 3℃. Under the design goal of thermal neutral, when the chilled ceiling surface temperature is in the range of 16–26℃, the air temperature should be set at 25.3–29.3℃; when the chilled floor surface temperature is in the range of 19–26℃, the air temperature should be set at 25.8–29.2℃. The design values of air velocity and relative humidity are not recommended to be changed, and still can follow the design standards for conventional all-air systems. Practical application: In this paper, some issues about indoor microclimate parameters design in radiant cooled buildings were discussed. A number of new thermal comfort charts using radiant cooling surface temperature and air temperature as dominant parameters were provided, and the design values of indoor air temperature, mean radiant temperature, air velocity, and relative humidity for radiant cooling system in residential buildings were also suggested. The research results can provide a more intuitive reference for the design of radiant cooling systems in residential buildings.

show abstract

Evaluating the low exergy of chilled water in a radiant cooling system

Cited by 19 publications

References 4 publications

Water and sunlight: regenerative hydronics

Water and sunlight: regenerative hydronics

Thermal Response Characteristics of Intermittently Cooled Room with Tube-Embedded Cooling Slab and Optimization of Intermittent Control

Analysis on combinations of indoor thermal microclimate parameters in radiant cooled residential buildings and drawing of new thermal comfort charts

Contact Info

Product

Resources

About