Most homes still use fossil fuel or an inefficient electric system for water heating. However, many people are now selecting super-efficient heat pumps to replace their aging systems. Heat pumps can be three to four times as efficient as the older technologies and are often the best option for low operating cost & low impacts on climate.
Cost Range
S$2,000 - S$2,500
(for typical flat)
About the technology
Is it New?: Not really — heat pumps have been around for years. For example, your refrigerator is one, and air conditioners are also heat pumps. However, the widespread application to home water heating is somewhat recent in many areas.
How it Works: Heat pumps use electricity to move heat from one place to another, instead of creating the heat directly. This is what makes them so efficient when compared to conventional heating systems.
Applicable Types of Heat Pumps: Various types of heat pumps are available to match a home’s particular needs. For example, some draw heat from the ground, some from well water, and some (the great majority) from the ambient air. Additionally, some are designed to just supply domestic hot water (such as for showers, etc.) and others also supply hot water for home heating through radiators or underfloor heating.
Economics: Heat pumps are generally more expensive to install than a conventional system. In many areas, however, incentives are available that can defray this additional cost. Additionally, you can often save money on your energy bills going forward, especially if you’re switching from heating with electricity, propane/LPG, or oil.
Environment: Heat pumps are a great way to reduce your carbon footprint. Their excellent efficiency, combined with the fact that they don’t burn fossil fuels, often lets them cut greenhouse gas emissions by 75% or more. Plus, as grid-supplied electricity becomes cleaner, the percentage reduction will grow over time.
Frequently Asked Questions (FAQ)
1. What is a heat pump water heater (HPWH)?
Heat pump water heaters use electricity to move heat from surrounding air to the water instead of heating the water directly. This process makes them very efficient – typically several times more energy efficient than standard electric water heaters — and can significantly cut water heating costs.
2. Does a HPWH store hot water?
Yes, unlike the instant water heaters that are sometimes used in homes, heat pump water heaters are storage water heaters available in tank capacities similar to standard storage water heaters. The heat pump components (compressor, heat exchangers, etc.) are integrated with the tank, so it can easily replace an existing storage water heater.
3. How much hot water is available for the household?
Heat pump water heaters come with different sizes. The most common capacities currently on the market range roughly from 30 to 100 litres, but tanks up to 300 litres are available. After being depleted of hot water, HPWHs (while operating in their efficient, heat pump mode) take longer to recharge than conventional electric water heaters. Accordingly, if you have the extra room, you might consider replacing your old water heater with a somewhat larger HPWH to compensate for this. For example, you might replace a conventional 40 litre water heater with a 60 litre HPWH.
4. What are the advantages of using a HPWH?
Heat pump water heaters use a proven energy-efficient technology. In switching from an electric water heater, a HPWH can reduce your ongoing water heating costs substantially. Also, since you’re using less electricity, there’s an environmental advantage to using a HPWH.
5. Is a tankless electric water heater more efficient?
No. Tankless electric water heaters can be at most 100% efficient since they directly heat the water with electricity. A HPWH just moves heat (instead of creating it) and can be effectively 300-400% efficient.
1. How much does a HPWH cost?
The cost of a heat pump water heater will be higher than the cost of a conventional water heater, perhaps in the neighborhood of S$2,000 – S$2,500 for most installations of small HPWHs. Many site-specific factors affect the installed cost of a HPWH, so it’s always a good idea to get cost estimates from local professionals.
2. How much can I save on energy costs with a heat pump water heater?
According to the National Environment Agency, a family of four will likely save about S$250/year compared to an instant water heater. When compared against a conventional electric storage water heater, the savings grows to S$330/year.
1. What are the steps needed to install a HPWH?
If you’re replacing a storage electric water heater with a HPWH, the process is generally quite straightforward. One can be switched out for the other. However, when switching from a gas water heater, an electrician may need to run an electrical line to where the HPWH is installed.
1. What maintenance does a HPWH require?
Unlike conventional water heaters, heat pump water heaters sometimes have an air filter that needs to be cleaned periodically to ensure efficient operation.
1. Can I save on carbon emissions if I switch to a HPWH?
Yes, it will reduce your carbon footprint. The amount of the reduction depends on the carbon intensity of the electricity used to power your HPWH and the amount of hot water you use.
1. How do I operate a HPWH?
Heat pump water heaters are generally more interactive than conventional water heaters. Most models feature a control panel that allows homeowners to select water temperature and operation mode. Some are WiFi connected and come with a smartphone app. The app lets you control the HPWH and examine energy consumption patterns that can then be used to optimize the usage.
2. What is the warranty on a HPWH?
It varies, but major manufacturers of heat pump water heaters sometimes offer 3-year (or longer) warranties on their products.