How Energy Saving is Your Water Heater?

After air conditioning, water heating is the second largest energy consumer in households in Singapore. We spend about 20% of utility bills on water heating. Whether you are buying a water heater with the latest technology for your home or replacing a leaky old one, it pays to choose carefully.

Walk into the various electrical and bathroom showrooms in Singapore and you will see an array of water heaters proclaiming their green credentials. They can claim to save from 10% all the way to 80% of energy, but is this true? Unfortunately for the environment and the home owner, it is soon discovered that most of it is just ‘greenwash’ churned out by a marketing department.


Eco Friendly Water Heater - How much do they really save? | AOS Bath

Eco Friendly Water Heaters – How much do they really save? Can we trust the energy saving percentages in the marketing material?

If you as a home owner are serious about saving the earth, you will appreciate a straightforward comparison backed by facts and figures. So why isn’t this available in Singapore just yet? The answer is simple, we are all just waiting for a formal third party ‘green’ rating and certification process to be set up here. But not to fret! If a green study like that has yet to be done in Singapore, we can easily draw parallels by using data from countries that are more advanced in this aspect.


Green geothermal heating systems that are common overseas may not be available in Singapore. | AOS Bath

Green geothermal heating systems that are common overseas may not be available in Singapore.

One very good gauge of how much your water heating system can save is the Energy Factor or EF of a water heating system. The Energy Factor is an international standard which measures the amount of energy your water heater consumes. The higher the EF, the more energy saving your system.

Water Heater Type Image Efficiency (EF)
Conventional gas storage Gas Storage Water Heater is the least energy saving | AOS Bath 0.60
High efficiency gas storage 0.65
Demand gas (instant gas heater) 0.82
Min efficiency electric storage 0.90
High efficiency electric storage 0.95
Demand electric (instant heater) 0.95 (estimated)
Solar heater storage Solar Heater Storage | AOS Bath 1.20
Electric heat pump water heater Electric Heat Pump Water Heater is the Most Energy Saving| AOS Bath 2.20

Source: American Council for an Energy-Efficiency Economy

According to the table above by the American Council for an Energy-Efficiency Economy,  an electric heat pump water heater is currently rated the most energy saving system, with an EF of 2.20. Moving heat is far less expensive than creating heat. By drawing ambient heat from the environment to heat up the water, a heat pump water heater requires much less energy than the conventional gas or electric water heater.

Besides energy consumption, there are also many other variables you should consider when getting a water heater, depending on your needs. These might include size, convenience and personal usage patterns. Always do your research before you make your purchases!

You can check out AOS Bath’s range of water heaters here.

More information on Energy Factor (EF) here.

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Amanda Zhong

Amanda Zhong

Amanda is the bookish personality of AOS Bath. She loves reading in quiet places over a good cup of tea. Like her other Gen Y peers, she has a penchant for advanced technology that delights and engages people.