Residential Water Heating Dehumidifier (WHD) With Devoted Dehumidification

Author(s):  
Aaron K. Ball ◽  
Chip W. Ferguson ◽  
Frank T. Miceli ◽  
Evelyn Baskin

A new a dual-service dehumidifier water heater (WHD) appliance is being researched and developed by the authors. Prior research on a similar appliance, a heat pump water heater (HPWH), has demonstrated the unit’s increased performance and energy saving, and through collaboration, significant progress has been made toward developing the WHD into a potentially marketable product. The primary energy use in residential households is space conditioning (49%), and the second major energy use is hot water consumption. In DOE’s 2004 Buildings Data Book, 15.5 percent of residential energy utilization is consumed by water heating (DOE 2004, Table 1.2.3). The two major types of residential water heaters are direct gas fired (~55%) and electric resistance (~45%) (DOE 2004, Appliance Magazine 2005). The maximum efficiency of a standard electric resistance water heater is 1 (100%), and progress has been made to increase the efficiency of the current standard heaters to approximately 95 percent (DOE 2004, Table 5.10.6), which is roughly the maximum available with today’s technology. However, if the standard system is replaced by a Heat Pump Water Heater (HPWH), the performance can be increased by 140 percent (Zogg and Murphy 2004). The WHD operates as a HPWH while heating water and as a dedicated dehumidifier when water heating is not necessary. This paper presents the general design and laboratory testing results of a WHD. Preliminary performance data reveal coefficient of performances (COP) of approximately 2.2 during water heating. Further, market analysis has revealed that a potential need for this new technology is in regions with high humidity (Ashdown et al. 2004). These regions are primarily in the Northeast, Southeast and some coastal areas of the U.S. Current HPWH units do not have dedicated dehumidification and have a very small share of the residential water heat market. Of the 9.55 million residential water heaters sold in 2003 only about 2,000 of them were HPWHs (DOE 2004, Table 5.10.15).

2016 ◽  
Author(s):  
Gabriel Agila ◽  
Guillermo Soriano

This research develops a detailed model for a Water to Water Heat Pump Water Heater (HPWH), operating for heating and cooling simultaneously, using two water storage tanks as thermal deposits. The primary function of the system is to produce useful heat for domestic hot water services according to the thermal requirements for an average household (two adults and one child) in the city of Quito, Ecuador. The purpose of the project is to analyze the technical and economic feasibility of implementing thermal storage and heat pump technology to provide efficient thermal services and reduce energy consumption; as well as environmental impacts associated with conventional systems for residential water heating. An energy simulation using TRNSYS 17 is carried to evaluate model operation for one year. The purpose of the simulation is to assess and quantifies the performance, energy consumption and potential savings of integrating heat pump systems with thermal energy storage technology, as well as determines the main parameter affecting the efficiency of the system. Finally, a comparative analysis based on annual energy consumption for different ways to produce hot water is conducted. Five alternatives were examined: (1) electric storage water heater; (2) gas fired water heater; (3) solar water heater; (4) air source heat pump water heater; and (5) a heat pump water heater integrated with thermal storage.


2014 ◽  
Vol 521 ◽  
pp. 748-751
Author(s):  
Zhao Xia Zhou

A survey for water heater in urban residential buildings is carried in Wuhan. The results show that more than 40% subjects use solar energy water heat. More than 20% subjects point out the energy consumption of water heater should be decreased. There are about 24.8% subjects take initial cost as the first place when they chose water heater. 44.2% subjects know about heat pump water heater, but they could not buy it if the initial cost is too high. There are 84% subjects could select heat pump water heater when the cost is no more 20% high than the average price of the common water heaters. Moreover, the energy consumptions of residential water heaters are also investigated. The energy consumption characteristics of water heater in Wuhan are analyzed.


2012 ◽  
Vol 512-515 ◽  
pp. 303-306
Author(s):  
Xue Lai Liu ◽  
Guan Zhu Wang ◽  
Yong An Li ◽  
Xiao Feng Zhang

This article describes the solar hot water system, and establishes the computational model of hot water system. It analyzes the economical efficiency of solar water heaters which equipped with electric water heaters, gas water heaters and air-source heat pump water heaters. The results show that the initial investment of the system which equipped with an electric water heater and a gas water heater is almost, but the operating cost which equipped with a gas water heater system is lower. The operating cost which equipped with an air-source heat pump water heater is the lowest, though the initial investment is the highest. The solar hot water system which equipped with an air-source heat pump water heater has important reference value for going low-carbon economy road in China.


Author(s):  
Jielin Luo ◽  
Qin Wang ◽  
Zhen Zhao ◽  
Kaiyin Yang ◽  
Guangming Chen ◽  
...  

Abstract Considering the issues of environmental pollution and energy efficiency, heat pumps are gradually replacing traditional coal combustion for heating at low ambient temperatures. In this paper, eco-friendly CO2/HCs with large temperature glides are applied in a single-stage recuperative heat pump water heater. Its heating performance is theoretically investigated under the working condition of producing circulating hot water in typical winter of northern China, with medium temperature difference between supply/return water and large temperature difference between air inlet and water inlet. Due to its simple structure, low initial investment and high efficiency, its potential for producing circulating hot water is demonstrated. Exergy analyses are conducted to reveal the significant influence of the exergy losses of heat exchanger on system performance. For specified CO2/HC, optimal COP is obtained through global optimization of cycle pressures and mixture concentration. The heating performances of different CO2/HCs are compared, among which CO2/R600 and CO2/R600a behave better. Meanwhile, a typical vapor-injection cycle is used to demonstrate priorities on the heating performance of this recuperative cycle, in which the COP of recuperative cycle using CO2/R600 is more than 3.4% higher than that of the vapor-injection cycle. The results obtained in this paper provide a simple and efficient solution for producing circulating hot water at low ambient temperatures.


Author(s):  
B. J. Huang ◽  
F. H. Lin

A compact and fast temperature-response heat pump water heater was designed using multiple tanks and a sequential control device. The supply tank was heated as a priority by a freon-line switching device to increase the temperature recovery speed. A dual-tank prototype with 100-liter capacity was built and tested. The experimental results show that the time for temperature recovery of the supply tank from 42°C to 54°C reaches 10–20 minutes and COP reaches 2.0–3.0 during various seasons. The prototype tests show that an energy saving around 50%–70% as compared to the electrical water heater can be obtained. The hot water discharge efficiency of the heat pump is 0.912.


Author(s):  
Yahya I. Sharaf-Eldeen ◽  
Craig V. Muccio ◽  
Eric Gay

This work involves measurements, analyses, and evaluations of the performance of add-on, Heat Pump Water Heater (HPWH) systems in residential and small commercial applications. Two air-source Heat Pump (HP) systems rated at 7,000- and 12,000-BTU (2.051- and 3.517-kWh), were utilized in this work. The two HPs were retrofitted to two 50-gallon (189.3 liters) electric-resistance storage water-heaters with their electric heating elements removed. A third, standard electric water-heater (EWH), was used for comparison. The testing set-up was fully instrumented for measurements of pertinent parameters, including inlet and outlet water temperatures, inlet and outlet air temperatures of the HPs, temperature and humidity of the air in the surrounding space, volume of water draws out of the storage heater tanks, as well as electric energy consumptions of the systems. Several performance measures were used in this work, including the Coefficient of Performance (COP), which is a measure of the instantaneous energy output in comparison with the energy input; Energy Factor (EF), which is an average measure of the COP taken over extended periods of time; and the First Hour Rating (FHR), which is a measure of the maximum volume of hot water that a storage type water-heater can supply to a residence within an hour. The results obtained clearly indicate that, HPWH systems are much more efficient as compared to standard EWHs. While the average value of the EF for a standard EWH is close to 1.0, the HPWH systems yield EFs averaging more than 2.00, resulting in annual energy savings averaging more than 50%. The results also showed that, HPWH systems are effective at reducing utility peak demand-loads, in addition to providing substantial cost savings to consumers.


Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 479
Author(s):  
Ignacio Paniagua ◽  
Ángel Álvaro ◽  
Javier Martín ◽  
Celina Fernández ◽  
Rafael Carlier

Although CO 2 as refrigerant is well known for having the lowest global warming potential (GWP), and commercial domestic heat pump water heater systems exist, its long expected wide spread use has not fully unfolded. Indeed, CO 2 poses some technological difficulties with respect to conventional refrigerants, but currently, these difficulties have been largely overcome. Numerous studies show that CO 2 heat pump water heaters can improve the coefficient of performance (COP) of conventional ones in the given conditions. In this study, the performances of transcritical CO 2 and R410A heat pump water heaters were compared for an integrated nearly zero-energy building (NZEB) application. The thermodynamic cycle of two commercial systems were modelled integrating experimental data, and these models were then used to analyse both heat pumps receiving and producing hot water at equal temperatures, operating at the same ambient temperature. Within the range of operation of the system, it is unclear which would achieve the better COP, as it depends critically on the conditions of operation, which in turn depend on the ambient conditions and especially on the actual use of the water. Technology changes on each side of the line of equal performance conditions of operation (EPOC), a useful design tool developed in the study. The transcritical CO 2 is more sensitive to operating conditions, and thus offers greater flexibility to the designer, as it allows improving performance by optimising the global system design.


Green ◽  
2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Brian Norton

AbstractSolar water heating can be considered to be an established mature technology. The achievement of this status is the outcome of over a century of system development that culminated with a flourish of innovation in the last thirty years. Drivers for research and development have been achieving economic viability by devising systems that, for specific applications in particular climate contexts produced more hot water per unit cost. Reductions in both initial capital and installation costs have been achieved as well as in those associated with subsequent operation and maintenance. Research on solar water heating is discussed with the emphasis on overall systems though some key aspects of component development are also outlined. A comprehensive taxonomy is presented of the generic types of solar water heater that have emerged and their features, characteristics and performance are discussed.


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