Home Heating 8 June 2023

How To Get The Best From Your Heat Pump

Heat pumps are a fantastic way to heat your home in winter and cool it in summer.

But understanding how your heat pump works and using it wisely can help reduce the cost of your electricity bill whilst still providing you with optimal comfort all year round.

To achieve maximum efficiency and long-term cost savings on your power bills, it's important to choose the right model for your space, operate it properly, and maintain it regularly.

With heating costs accounting for more than 35% of winter power bills, getting the best from your heat pump is crucial.

Do heat pumps use a lot of electricity?

Heat pumps are a very cost-effective alternative to traditional electric heating options – this is because they transfer heat instead of generating it.

According to EECA Energywise, the cost of running a heat pump ranges from 3 to 16 cents per kilowatt-hour (kWh) of heat produced, while a traditional electric heater can cost between 19 and 40 cents per unit.

Heat pumps are highly energy-efficient, producing 3-5kW of heat energy for every 1kW used. They typically take 10-20 minutes to bring a room up to temperature and then maintain it.

To maximise energy efficiency, it’s important to start with the right heat pump type and size for your space. Learn more about choosing a heat pump. To get the best from an existing heat pump, read on. 

What temperature should I set my heat pump to?

The best temperature range for your heat pump will vary between the seasons. It’s recommended that your heat pump runs between 18 – 22 degrees Celsius in cooling mode during the summer to save energy. Your home won't cool down any quicker if you set the temperature lower, but your unit will work a lot harder – meaning you'll use more energy.

To get the most out of your heat pump in winter, we recommend setting the temperature to 18-22 °C in heating mode for optimal energy efficiency and cosiness. Wonder how changes in temperature can affect you? Read more here.

When setting your heat pump’s temperature overnight, it is better to choose a temperature that is lower to what you set during the day. That’s because our bodies don’t need as much heat while we’re sleeping compared to when we’re awake. We recommend between 16 to 18 degrees Celsius, but no lower than 15 degrees Celsius.

Is it better to leave a heat pump on all the time?

One of the best things about heat pumps is that they have been specifically designed to be as energy efficient as possible when running for long periods of time. Leaving your system on to heat your home can often be the wiser choice instead of turning it off & on again, as it uses less energy to maintain a room’s temperature but more energy to change it.

However, if you’re leaving the room for more than a couple of hours, it’s best to turn your system off. Keeping your heat pump on when it’s not needed can lead to even higher power bills and cause your system to break down faster than it should.

If you’d like to return to a perfectly warm home, instead of leaving your heat pump on all day, you can set the programmable timer instead. These work by turning your heat pump on or off at pre-determined times chosen by you. Rinnai Heat Pumps also come with a Wi-Fi phone app, allowing you to adjust your heat pump settings from anywhere, at any time. If you aren’t sure which Rinnai Heat Pump best suits you, we’re here to help.

What is the most efficient way to use a heat pump in summer?

The most efficient way to use a heat pump in summer is not as difficult as you may think – here are some useful tips we have pulled together to help you run your heat pump more efficiently throughout the summer months to create a cool and comfortable home living environment without breaking the bank.

1. Minimise the amount of space you are trying to cool

Reducing the amount of space that your heat pump is trying to cool is one of the easiest and most effective ways to stay comfortable whilst reducing energy use. The less space your heat pump has to heat or cool, the less amount of time it will need to run and the less energy it will consume. Create cooling zones by only cooling the spaces that are being used, close any open doors and block off any entrance ways that may allow the cold air to escape. This helps the main areas of your home cool down faster and in turn, reduce energy consumption.

Additionally, try the Dehumidifying or Fan Only mode. This mode is more energy efficient than full cooling mode and the reduced humidity or airflow may be sufficient enough to provide a comfortable environment.

2. Make use of inbuilt timers & wi-fi functionality

Most split systems and ducted systems offer timer functions and Wi-Fi capabilities, enabling you to have control over when your unit starts and stops operating. For example, you can utilise built-in timers and a Wi-Fi app to schedule the cooling of your bedroom an hour before you plan to sleep on a warm night. This ensures a comfortable environment for a restful sleep while minimising the impact on the heat pump.

To further optimise energy efficiency, consider using programmable timers to start the heat pump unit earlier in the day. During the early hours, both the indoor and outdoor air temperatures tend to be cooler, allowing the heat pump to consume less energy in reaching the desired temperature throughout the day. On the other hand, activating the heat pump during the hottest part of the day puts excessive stress on the system, causing it to work harder and take longer to cool down your space.

3. Check the filters

Without regular cleaning the build-up of dust and debris can clog the air filters of your heat pump and restrict air flow. Cleaning your filters regularly will ensure that your heat pump operates at greatest efficiency and reduces unnecessary energy consumption.

The air filters also restrict pollen, dust and detritus from outside being blown into the home, and they can also become damp and mouldy, so it is essential that they get cleaned regularly.

Clean dust from the filters with a vacuum cleaner or wash with mild detergent and warm water each month. Ensure the filter is completely dry before replacing. Dust that builds up along the indoor unit grilles and the louvers can also be vacuumed and wiped with a damp cloth.

4. Have your heat pump serviced regularly

Heat pump servicing is often overlooked as an integral part of maintaining the longevity and efficiency of a heat pump system. But you need to look at heat pump servicing like you would servicing your car – it keeps it performing well and increases the life of your investment.

Heat pumps are all about efficiency, and by maintaining efficiency, regular servicing will keep running costs low and help it perform at its best throughout its full life cycle.

The key to heat pump longevity and efficiency is to have them serviced before you actually need to. Waiting for an issue to arise is both costly and inconvenient. A service of your heat pump each year will address any issues before those first sweltering and humid days of a true NZ summer hit.

How can I make my heat pump heat better?

If your heat pump is turned to heating mode, but your home is either not getting warm enough, or it’s not getting warm at all, here’s a few ways to make your heat pump heat better:

1. Clean the air filter

A clogged air filter is one of the most common causes of a heat pump not blowing hot air. Your heat pump’s air filter is a hard working and important part of  your heat pump system whose job it is to filter out dust, allergens, and other pollutants that come from the outside air - but when too much of these particles build up, it can block airflow to the compressor, the part of the unit that actually heats the air. Regular cleaning of your filters, at least every 3 months, and having your heat pump professionally serviced each year will help your system deliver all the warm air you will need throughout the winter months.

2. Check that the outdoor unit is clear of debris

Your heat pump pulls heat from the air outside into your home. If the airflow to your unit is blocked by ice, leaves or other types of garden debris, this can make it hard for the heat pump to do its job. Clean off your heat pump and clear away any debris that may be built up around your outdoor unit.

3. Refrigerant charge may be low   

If the levels of refrigerant in your system are insufficient, which is often caused by a leak, your heat pump will face difficulty in generating enough heat to warm your home. It is advisable to have a professional inspect your system to determine if the refrigerant levels are too low or if a recharge is required. Refrigerant plays a crucial role in both cooling and heating processes. Inadequate presence of this gas in the system will hinder your heat pump's ability to effectively heat the air.

4. Defrost Cycle

The Defrost Cycle occurs while the heat pump is in heating mode, extracting heat from the outside air and transferring it inside your home. When the outside ambient temperature drops very low (around 0°C or below), the moisture in the outdoor air freezes on the heat exchanger coil of the outdoor unit as the fan blows air over it. The Defrost Cycle is activated when the heat pump detects the formation or initial formation of ice on the heat exchange coil, and it automatically addresses this issue.

During the defrost mode, you will observe some changes in the operation of the heat pump. The indoor unit will stop providing heat, the indoor fan will either stop completely or slow down significantly, and depending on the model, there may be blinking lights on the indoor unit. The outdoor unit's fan will stop running, but the compressor will continue to operate.

5. Is the heat pump the right size for your space?

If you install a Heat Pump that’s too small, it may struggle to keep the room at the required temperature and will use more energy to do so. Too large, and the heat pump will need to cycle on and off to keep the temperature in the desired range.

There are many other variables that need to be considered for an effective and efficient comfort solution for your unique space. Here are some to think about:

Location and Aspect. Some areas in New Zealand experience sub-zero temperatures which require larger Heat Pumps than in more temperate regions. Queenstown and Auckland have quite different requirements, so appropriate unit selection is important.

The sun is our most valuable (and free) source of heat, so it can really affect the temperature inside a room with heat transfer through walls and windows. Considering the influence of the sun, rooms that are facing east or west may need a different capacity Heat Pump compared to a north-facing room.

Windows. A room that has plenty of windows can be draughty as well as allowing heat and cold to enter or escape quickly. The size of your windows and insulating properties of the glass will have a greater effect on the size of the Heat Pump and its ability to optimally heat the space more than the walls and ceilings of the room. Having larger windows in a room may mean that your heat pump will struggle to maintain the output of desired heat.

If you’re investigating options to keep your home warm and dry and how to get the best from your heat pump, discover the Rinnai home heating range, or dive into our ducted or highwall heat pump options.  If you don’t know where to start, this guide walks you through how to choose a home heating solution.

Related Articles