This semester project investigates strategies aimed at controlling the aggregate power demand of large groups of domestic electric water heaters. An existing model of a single electric water heater that considers thermal stratification along the height of the hot water tank was tuned and verified using experimental data. The tuned model was then incorporated into an existing model of a water he...

Hot water supplies account for approximately 30% of energy consumption in residential sectors of Japan; it is therefore important that the energy efficiency of water heaters be improved. Absorption heat pump water heaters are expected to provide greater efficiency than conventional water heaters that use gas. However, the absorption systems have larger volumes and are not widely accepted in the...

Many companies in India manufacture solar water heaters but these are not becoming popular in the domestic sector because of their high cost. The Ministry of Non-Conventional Energy Sources (MNES), New Delhi is recommending flat-plate collectors with copper (Cu) risers, headers and plate. Therefore, their cost is high. Long term studies have been carried out at the Central Arid Zone Research In...

bubble columns are gas- liquid contactors that are widely used in chemical and bio- chemical industries. high mixing that result in high heat and mass transfer rates are amongst their advantages. heat transfer in a bubble column having a bundle of heaters investigated and the variation of heat transfer coefficient with variation in heaters pitch to diameter ratios in a bundle of heaters reporte...

Relative to solar water heaters, solar air heaters have received relatively little investigation and have resulted in few commercial products. However, in the context of a humidification-dehumidification (HDH) desalination cycle, air heating accounts for advantages in cycle performance. Solar collectors can be over 40% of an air-heated HDH system’s cost; thus, design optimization is crucial. Be...

Legionnaires’ disease is often acquired by inhalation of legionellae from a contaminated environmental source. In recent years, Singapore has seen an increase in the use of aerosol-generating fixtures such as mist fans and spa pools. Poorly maintained and designed water fixtures could pose a public health threat to the community. In this study, we provided an update on the prevalence of Legione...

Carbon monoxide (CO) poisoning from natural gas water heaters is a common household accident in Taiwan. We propose a wireless and batteryless intelligent CO sensor for improving the safety of operating natural gas water heaters. A micro-hydropower generator supplies power to a CO sensor without battery (COSWOB) (2.5 W at a flow rate of 4.2 L/min), and the power consumption of the COSWOB is only...

With the urbanization process of the hot summer and cold winter (HSCW) zone in China, the energy consumption of space and water heating in urban residential buildings of the HSCW zone has increased rapidly. This study presents the energy efficiency and sustainability evaluation of various ways of space and water heating taking 10 typical cities in the HSCW zone as research cases. Two indicators...