It wouldn’t be a New Zealand summer without a period of uncomfortable temperatures. Your heat pump / air conditioning system will work super hard during the peak season to keep your home cool, which means energy consumption and costs could climb without you even realising.

Soaring temperatures shouldn’t mean sweltering in the heat for fear of a higher than average energy bill. We’ve put together some useful tips on the best way to run a heat pump / air conditioner in summer to create a comfortable living environment, all without breaking the bank.

Related Article: Fujitsu’s Heat Pump Dry Mode

Preparation and maintenance are key

If you already have a reverse cycle heat pump / air conditioning system installed, it's valuable to spend some time giving it some attention either side of summer. A little heat pump maintenance will ensure it's running at its best when you need it, whether that’s throughout the warmer or cooler months.

Operating a heat pump / air conditioner that is poorly maintained can lead to poor efficiency. This means the unit will need to work much harder to cool the home, putting pressure on energy consumption and ultimately the household budget. It’s best to have a heat pump / air conditioning system serviced periodically by a licensed technician. Depending on use this could be every one to two years.

During regular use, filters within the indoor heat pump / air conditioning unit accumulates dust, which if left uncleaned can clog the unit, reducing air flow and diminishing performance of the heat pump / air conditioner. Clean dust from reusable filters with a vacuum cleaner, or wash with mild detergent and warm water each month. Ensure the filter is completely dry before replacing. For disposable filters, replace as required according to the manufacturer’s instructions. Dust that builds up along the indoor unit grilles and the louvers can also be vacuumed and wiped with a damp cloth.

Perfect your settings

When the temperature outside is unbearable, it can be very tempting to lower the heat pump / air conditioning temperature indoors to try and cool the room faster. However, this can put unnecessary pressure on the system and contribute to an increase in energy use. In summer, we recommended setting the temperature around 23 degrees celsius, or as high as you feel comfortable with, to create a comfortable environment while minimising energy consumption. Increasing your heat pump / air conditioning thermostat by just one degree in warm weather can reduce the running cost of your appliance.^[1]

The right timing

There are a number of ways to maximise heat pump cooling efficiency in hot weather. Most heat pump / air conditioning systems include in-built timers, so you’re not only setting the temperature, but setting the hours of operation for minimal energy output. For example, the in-built timer can be set to start cooling a bedroom on a warm night an hour before you plan to go to sleep. This helps create a comfortable environment for a restful sleep, and puts minimal impact on the heat pump / air conditioning system.

Use programmable timers to start the heat pump / air conditioning unit earlier in the day. At the beginning of the day, the air inside and outside the home is generally cooler, which means the heat pump / air conditioning system uses less energy to reach the set temperature throughout the day. Switching the heat pump / air conditioner on during the hottest part of the day puts an excessive amount of pressure on a system, making it work much harder, and taking longer to cool down the home.

Create cooling zones

Only cool the room, or rooms, that are being used. It makes sense not to waste power cooling rooms that are empty, particularly if they’re not in use for long periods of time during the day when kids are at school or parents are working. This helps the main areas of the home to cool down faster, reducing energy consumption. If you live in a large home, installing a Fujitsu General Ducted system with zone control allows individual areas to be cooled as desired. Otherwise, closing doors or shutting off access to rooms or areas that aren’t being used, can also help.

Insulate and seal the home

A home without any insulation can make the heat pump / air conditioning system work harder than it needs to by putting pressure on the unit to keep the room at the desired temperature. Ceiling insulation can cut your energy use by 45 per cent, which makes it a worthwhile investment.^[2] If you’re unsure if you have ceiling insulation, a good way to check is to place your hand on the ceiling on a warm day, if it feels really hot, it’s unlikely you have insulation. With the price of energy set to rise, installing insulation now will keep your home cooler during summer, warmer in winter, and help to reduce excessive energy bills in the future.^[3]

How to Use a Heat Pump Efficiently NZ: Frequently Asked Questions

What are the best heat pump / air conditioner settings for summer?

The best way to run a heat pump / air conditioner in summer is to set the temperature to the highest comfortable temperature, which is anywhere from 23°C to 25°C.

How long should a heat pump run in the summer?

Running a heat pump / air conditioner in summer can use more energy than in the cooler months. Heat pump / air conditioners run for longer on extremely hot days to maintain a comfortable temperature. The runtime of your heat pump / air conditioner can vary based on the specifications of your unit, the set temperature, your home’s insulation and the severity of the outdoor temperature. For exact runtime details, it’s best to research the specifications of your unit or contact a heat pump / air conditioning professional at Fujitsu General. 

If you require any more information or assistance, contact Fujitsu General to discuss our heat pump / air conditioning solutions further. 

^[1] https://www.environment.sa.gov.au/goodliving/posts/2018/01/keeping-cool-efficiently

^[2] https://www.abs.gov.au/ausstats/[email protected]/2f762f95845417aeca25706c00834efa/0FE2CFD2F9C2F863CA25750E001089CB?opendocument&sa=D&source=docs&ust=1707948537459827&usg=AOvVaw1C7N9-0Tr6q_IZOlDy-QO-