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.
| WATER HEATER TYPE | IMAGE | EFFICIENCY (EF) |
|---|---|---|
| Conventional gas storage water heater |  | 0.60 |
| High-efficiency gas storage water heater | 0.65 | |
| Demand gas (instant gas heater) |  | 0.82 |
| Min efficiency electric storage water heater |  | 0.90 |
| High-efficiency electric storage water heater | 0.95 | |
| Demand electric (instant heater) |  | 0.95 (estimated) |
| Solar water heater (storage) |  | 1.20 |
| Electric heat pump water heater |  | 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 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.
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.
