There are several factors to be considered when selecting the most efficient and effective electric water heating solution for multi-residential dwellings.

Environmental performance, efficiency, installation quality, and energy and water running costs are key considerations that come into the equation when determining the most suitable option.

Centralised hot water services for multiple dwelling buildings in Australia are mostly gas-fired, while standalone instantaneous water heating units are either gas-fired or electrical. Electric instantaneous hot water systems with 99.5% heating efficiency are far superior to gas-fired hot water systems that have burner heating efficiencies of 80-85%.

Energy efficiency and sustainability are major concerns across commercial and residential segments with a key goal among end-users being to minimise their impact on the natural environment. The cost of energy and water is a significant domestic outgoing; a simple and direct way any individual can lessen their environmental impact is to reduce the resources that they consume in daily life, particularly water usage in hot water systems.

In addition to heating efficiency, instantaneous electric systems offer advantages in terms of system architecture, installation quality, clean energy source and operating costs, all of which contribute to the overall system efficiency and environmental performance.

While most environmental impact studies focus solely on energy usage, the water wastage aspect must be considered given the fact that most parts of Australia regularly face water restrictions and price increases.

Architects and builders face increasing pressure to enhance the sustainability factor of buildings. While evaluating the suitability of hot water systems for their buildings, they have to choose between centralised boilers that service the whole building and individual instantaneous water heaters installed in each apartment.

Multi-dwelling residential developments provide an ideal setting for demonstrating the water saving potential as well as other benefits of instantaneous hot water systems.

By selecting electric appliances, builders can simplify the infrastructure requirements of an apartment block, removing the need for independent gas feeds to each apartment. An instantaneous electric hot water solution can be positioned exactly where it is needed without the restrictions associated with gas feeds, flues or venting.

From the three options of instantaneous electric, instantaneous gas and centralised gas water heating systems for multi-residential dwellings, the instantaneous electric option has the least infrastructure requirements, and therefore represents the most cost-efficient choice for installation.

Though centralised gas-fired water heating systems are generally assumed to have the lowest carbon footprint of the three systems available, the need for continuous operation regardless of demand can lead to inefficiencies in energy usage.

Typically, a centralised hot water plant comprises of a ring-main that extends throughout the building, with individual feeds to each apartment. However, the long pipe runs from the storage tank to the apartment lead to heat loss, and consequent energy wastage.

Additionally, water in each of the apartment feeds is often significantly colder than the water circulating in the ring-main, necessitating the cold water to be drained from the feed to get water at the desired temperature. This leads to significant water wastage every time hot water is required in the apartment.

Very importantly, centralised systems also often present a more expensive initial cost for a property developer, given the requirements for a dedicated plant room, large commercial gas boilers, hot water storage tanks, circulating pumps, and the reticulation pipework, not to mention the higher ongoing maintenance costs.

Standalone instantaneous electric water heating systems offer several functional and cost advantages to the homeowner since water is only heated at the time of use, eliminating energy wastage and reducing operating costs.

Key benefits of instantaneous hot water systems include shorter pipe-runs resulting from heating units located closer to the point-of-use as well as less water wasted by the user while waiting for sufficiently hot water to arrive at the outlet.

Studies have shown that a typical apartment fed from a centralised gas-fired system wastes 7,000 litres of water over the course of a year, simply through the wait for hot water to arrive at the tap. An instantaneous electric water heater system can reduce this down to less than 1,600 litres.

Gleamous Australia Pty Ltd  supplies an energy-efficient range of instantaneous electric hot water systems designed to save energy, water and money from the first day of operation.