Performance characterization of an indoor air source heat pump water heater for residential applications in Canada

Abstract

Summary Air source heat pump water heater (ASHPWH) is a relatively new addition to delivering hot water at reasonably high efficiency. ASHPWH systems have achieved significant acceptance for mild to warm climate regions where space heating is minimal or none. However, limited performance mapping is available on these water heaters in extreme cold climatic conditions, such as Canada. The paper has examined the long‐term performance of this technology in Canadian context. The investigation has established the performance characteristics of ASHPWH unit through a series of pre‐defined indoor tests and theoretical simulations. The coefficient of performance and other critical parameters of ASHPWH were established and discussed in detail. A model was developed, validated, and used to show the impact of such type of water heater on the overall energy consumption in the house. The results indicate that the summer cooling decreases and the winter heating increases in the house with an indoor ASHPWH unit. Nevertheless, the net effect leads to 21.3% reduction in the total electricity consumption of the house (space heating, cooling, and water heating). Research provided an accurate performance prediction of ASHPWHs for year‐round applications in Canadian homes.

Experimental study on the performance of air source heat pump system with multiple parallel outdoor units

“…Air source heat pump system, which uses air as low temperature heat source (abbreviated as ASHP) has increased worldwide, and it can be used in almost the entire Pacific region . The ASHP can help save energy and reduce air pollution emissions . Correspondingly, Chinese government have made some very important policies, such as the “Coal to Electricity” to reduce and eventually eliminate the smog air pollution in winter.…”

“…27 The ASHP can help save energy and reduce air pollution emissions. 3,4,35 Correspondingly, Chinese government have made some very important policies, such as the "Coal to Electricity" to reduce and eventually eliminate the smog air pollution in winter. However, when an ASHP operates in winter, with the low atmospheric temperature, especially under high outdoor air humidity, the frost adhere to the heat exchanger fins will increase both heat transfer resistance 26 and airflow resistance, 31 then reduce the heat transfer rate 32,33 and degrade the performance of the unit or even result in an undesired shutdown.…”

Optimizing 100%‐renewable grids through shifting residential water‐heater load

“…In recent literature, we see contemporary models detailing the improvements and modifications to the designs of the standard air‐source heat pump water heater and the hybrid solar water heater. An air‐source heat pump water heater with the minitube condenser is suggested by Ibrahim et al Although the air‐source heat pump water heater is widely used in regions with mild to warm climate, its indoor use with some design modifications is recommended and tested for colder regions like Canada in previous studies . Tanha et al presented an altered design of the hybrid solar‐EWH by adding a drain‐water heat recovery unit, enabling their design to reduce its electricity consumption and provide demand flexibility.…”

“…Several shortcomings identified in the literature that relate to residential EWHs used as controllable appliances for load‐shifting are as follows: The absence of a nationwide aggregate EWH load model that can be used to analyse potential capacity reductions in a renewable‐only grid that can be achieved through load‐shifting in previous studies Previous studies that have focused on load‐shifting are set in a traditional electricity grid that rely on fossil fuel for power generation and do not consider a 100%‐renewable electricity grid.…”

Predictive control based on occupant behavior prediction for domestic hot water system using data mining algorithm

“…In Brazil, electric hot water for showers accounts for 24% of a typical household's energy consumption . In other countries, such as the US and various nations in the European Union, domestic hot water consumption accounts for approximately 14%‐25% of the total energy consumption in residential buildings . Because the energy consumption of a hot water system is relatively large, special attention should be paid to reducing building energy consumption.…”