How Energy Saving is Your Water Heater?

After air conditioning, water heating is the second-largest energy consumer in households in Singapore. An average household spends 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 homeowner, it is soon discovered that most of it are just ‘greenwash’ churned out by a marketing department.

If you, as a homeowner, 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.

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

Conventional gas storage water heater0.60
High-efficiency gas storage water heater0.65
Demand gas (instant gas heater)0.82
Min efficiency electric storage water heater0.90
High-efficiency electric storage water heater0.95
Demand electric (instant heater)0.95 (estimated)
Solar water heater (storage)1.20
Electric heat pump water heater2.20

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 the most energy-saving system, with an EF of 2.20. Getting free heat from the air is less expensive than creating heat with heating elements.

A heat pump water heater requires much less energy than conventional systems like gas or electric water heaters by drawing ambient heat from the environment to heat the water.

What Is Your Water Heater’s Power Consumption?

To calculate your water heater’s power consumption, first determine the number of people in your family. Assume 2 showers a day. 

usage of water heater per day

A typical Singaporean household of 4 will use the heater for about 2.67 hours a day. Use this Electricity Bill Calculator to find the monthly energy cost. Assume current tariff of around 31 cents (Nov 2022). You can get the most current Tariff at this website.  

Sample computation of how much does water heater cost in Singapore.

A family of four uses around $77 to heat up a tank each month, that amounts to $930 a year.

Besides energy consumption, you should consider many other variables 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.

Frequently Asked Questions About Energy-Saving Water Heaters

Why Do You Recommend Heat Pumps Over Solar?

Compared to solar heaters which have a heating efficiency of 50%, heat pumps operate at a higher efficiency of 80%. In Singapore’s unique climate, heat pumps are more popular because of their higher efficiency levels.

Renewable energy water heaters like solar and heat pumps are the most energy-efficient heating systems internationally. They have the highest Energy Factor (EF) of the various water heater types.

As a dedicated water heater specialist, A. O. Smith produces a full range of water heaters. Generation 1 heaters are the least energy-efficient with the lowest initial cost. Digital heaters are higher efficiency systems which offer you 10% savings, while renewable energy solar and heat pump heaters can save you 50-80% energy in total.

Electric water heaters: 3000W

Micro heat pumps: 210W

Central heat pumps: 460W

Heat pumps draw in plenty of free energy from heat in the ambient air. Micro heat pumps alone can save an estimated $600/year.

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Amanda is an education specialist at AOS Bath. She enjoys building a trusted network by sharing knowledge. Making difficult concepts simple and engaging is rewarding, on both ends.