scholarly journals Heat Loss from Hot Water Floor Heating System to Crawl Space: Field Survey and Improvement of Energy Consumption

2003 ◽  
Vol 2 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Hisashi Miura ◽  
Shuichi Hokoi ◽  
Nobuo Nakahara ◽  
Huang Yinong
Keyword(s):  
Energy Consumption ◽  
Heat Loss ◽  
Field Survey ◽  
Heating System ◽  
Hot Water ◽  
Crawl Space ◽  
Floor Heating

scholarly journals Thermal Comfort Analysis of Combined Radiation-Convection Floor Heating System

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1420 ◽  
Author(s):  
Beungyong Park ◽  
Seong Ryong Ryu ◽  
Chang Heon Cheong
Keyword(s):  
Energy Consumption ◽  
Thermal Performance ◽  
Thermal Environment ◽  
Heating System ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Convection Heating ◽  
The Difference ◽  
Floor Heating

In this paper, a novel combined radiation-convection floor heating system is shown. This study uses practice-based learning and investigated the thermal performance of a combined radiation-convection floor heating system with a water heat pump system by evaluating the thermal environment and energy consumption in an experimental test. A new method that analyzed the thermal performance of four different controls was developed and applied. The results of the surface temperature distributions demonstrated that Mode 1, which uses only convection, had the lowest floor temperature and was thus considered inappropriate for occupants who sleep on the floor. By contrast, Modes 2, 3, and 4 showed high floor surface temperatures as hot water was supplied to the radiant heating panel. The predicted mean vote (PMV) results suggest that radiant floor heating is not appropriate for intermittent heating. In other words, occupants of single residences who return home at night will experience a long period of discomfort if they heat their room using floor heating. In this case, Mode 1, which is convection heating, and Modes 3 and 4, which represent mixed modes provide a more comfortable environment. The difference between this experimental study and previous research is that four different control modes for a combined radiation-convection system were evaluated based on the same location of the equipment in a laboratory. Furthermore, we studied the long-term real-scale thermal performance using panel and energy consumption.

Effect of Building Height on Energy Consumption of Radiator and Floor Heating Systems

2011 ◽  
Vol 110-116 ◽  
pp. 4636-4642 ◽  
Author(s):  
Vahid Golkarfard ◽  
Pouyan Talebizadeh ◽  
Mazyar Salmanzadeh
Keyword(s):  
Energy Consumption ◽  
Heat Loss ◽  
Cfd Simulation ◽  
Heating System ◽  
Cold Season ◽  
Temperature Gradients ◽  
Convective Heating ◽  
Heating Systems ◽  
Impressive Result ◽  
Floor Heating

Buildings are one of the most important energy consumers in the world. High temperature gradients in heating systems can cause the increase of heat loss of the envelopes during the cold season and consequently increase the energy consumption. Floor heating systems has shown that they can generate lower temperature gradients in compare with other convective heating systems. In present study, the CFD simulation is done for a 3-D room and the required energy to achieve the thermal comfort in a room is calculated. The height of the room is changed and the energy loss of the room is calculated for both systems. Results showed that as the height doubles, the wall heat loss for radiator system almost doubles but for the floor heating system it was about 60 percent. This impressive result can recommend the floor heating systems for working areas with tall ceilings.

scholarly journals Overview of Solutions for the Low-Temperature Operation of Domestic Hot-Water Systems with a Circulation Loop

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3350
Author(s):  
Theofanis Benakopoulos ◽  
William Vergo ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Svend Svendsen
Keyword(s):  
Low Temperature ◽  
Heat Loss ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Heating Power ◽  
Circulation Loop ◽  
Space Heating ◽  
District Heating System ◽  
Domestic Hot Water

The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.

Evacuated Tube Heat Pipe Solar Collectors Applied to Recirculation Loop in a Federal Building: SSA Philadelphia

Solar Energy ◽  
2004 ◽  
Author(s):  
Andy Walker ◽  
Fariborz Mahjouri ◽  
Robert Stiteler
Keyword(s):  
Solar Energy ◽  
Heat Pipe ◽  
Heat Loss ◽  
Heating System ◽  
Hot Water ◽  
Solar Array ◽  
Solar Collectors ◽  
Water Heating ◽  
Evacuated Tube ◽  
Recirculation Loop

This paper describes design, simulation, construction and measured initial performance of a solar water heating system (360 Evacuated Heat-Pipe Collector tubes, 54 m2 gross area, 36 m2 net absorber area) installed at the top of the hot water recirculation loop in the Social Security Mid-Atlantic Center in Philadelphia. Water returning to the hot water storage tank is heated by the solar array when solar energy is available. This new approach, as opposed to the more conventional approach of preheating incoming water, is made possible by the thermal diode effect of heat pipes and low heat loss from evacuated tube solar collectors. The simplicity of this approach and its low installation costs makes the deployment of solar energy in existing commercial buildings more attractive, especially where the roof is far removed from the water heating system, which is often in the basement. Initial observed performance of the system is reported. Hourly simulation estimates annual energy delivery of 111 GJ/year of solar heat and that the annual efficiency (based on the 54 m2 gross area) of the solar collectors is 41%, and that of the entire system including parasitic pump power, heat loss due to freeze protection, and heat loss from connecting piping is 34%. Annual average collector efficiency based on a net aperture area of 36 m2 is 61.5% according to the hourly simulation.

Implementation of Solar Thermal Driven Absorption Cooling in the Southeast

2010 ◽  
Author(s):  
Stephen M. Smith
Keyword(s):  
Heating System ◽  
Hot Water ◽  
Solar Thermal ◽  
Absorption Chiller ◽  
Solar Absorption ◽  
Modeling Process ◽  
Annual Behavior ◽  
Cooling Loads ◽  
Radiant Floor Heating ◽  
Floor Heating

A 35,000 ft2 [3,251 m2] Creative Arts instruction building is being constructed on the campus of Haywood Community College in Clyde, NC (∼25 miles [40 km] west of Asheville). The building’s HVAC system consists of a solar absorption chiller, two parallel back-up electric chillers, and radiant floor heating with condensing boiler back-up. Hot water is to be heated by 117 solar thermal panels with thermal energy storage in a 12,000 gallon [45,000 liters] insulated tank and service to both the absorption chiller and the radiant under-floor heating system. Peak cooling loads and unfavorable solar conditions are to be handled by parallel electric chillers, operated in sequence to achieve maximum performance. Emergency radiant under-floor heating hot water back-up is to be handled by gas-fired condensing boilers in the event of unavailable solar heated hot water. This paper will examine the extensive modeling process required of the system as performed in EnergyPlus, how preliminary modeling results influenced the control and design strategy, the annual behavior of the system and the importance of controllability.

Research on Thermal Storage Effect of Floor Heating System with Phase Change Energy Storage

2012 ◽  
Vol 512-515 ◽  
pp. 2904-2907
Author(s):  
Guo Hui Feng ◽  
Kai Liang Huang ◽  
Xin Liu ◽  
Hui Xing Li
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Heat Dissipation ◽  
Thermal Storage ◽  
Heating System ◽  
Hot Water ◽  
Double Layers ◽  
Material Research ◽  
Storage Effect ◽  
Floor Heating

The floor heating system of phase change energy storage (FHSPC), performing well in storing and releasing thermal energy, plays a significant role in using solar energy and low-priced nocturnal electrical power for heating. However, due to such problems as ineffective package and insufficient overall integration of phase change material, research of FHSPC has not made progress in practical application. This paper researches thermal storage effect of a new floor heating system of phase change energy storage using solar hot water as the heat source and double layers of capillary network as the heat dissipation end. Differential scanning calorimeter was used to choose capric acid as the main energy storage material. For a steady heating cycle of heating for 8 hours and releasing for 16 hours, acceptable thermal condition is observed in the test room. The new FHSPC could provide long span intermittent heating with little heat loss, therefore the intermittent energy source can be well utilized

scholarly journals Thermodynamic analysis on an instantaneous water heating system of shower wastewater source heat pump

2017 ◽  
Vol 8 (3) ◽  
pp. 404-411 ◽  
Author(s):  
Yuguo Wu ◽  
Yake Jiang ◽  
Bo Gao ◽  
Zhigang Liu ◽  
Jing Liu
Keyword(s):  
Heat Transfer ◽  
Energy Consumption ◽  
Heat Pump ◽  
Water Reuse ◽  
Heating System ◽  
Water Systems ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Heat Transfer Area ◽  
Discharge Pressure

Abstract Water reuse and desalination systems are energy intensive processes, and their increasing use is leading energy consumption within water systems to be an increasingly important issue. Shower wastewater contains large amounts of heat, so there is an opportunity to recover energy from shower water to offset energy consumption elsewhere in water systems. This paper found ways to increase the output of hot water and lower the energy consumption by establishing a thermodynamic model of an instantaneous wastewater source heat pump. The system proved to be very effective, the heating COP (coefficient of performance) can reach 3.3 even in the winter. Under the conditions of limited heat transfer area, reducing the suction pressure of a compressor is a more feasible way to increase the hot water output to meet the needs of users rather than increasing the discharge pressure. Besides, increasing the heat transfer area of the evaporator is a more effective option. When the heat transfer area of evaporator varies from 0.5 to 1.0 square meters, a notable change is that the heating COP increases from 3.283 to 3.936. The heating COP in a system with a recuperator can reach 5.672, almost double that compared to the original systems.

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