Electric heat pumps have become an incredibly popular form of heating in New Zealand in the last 15 years, with ease of use being one of their main advantages.
A heat pump is essentially a heat transfer system. It moves warm air into spaces that have colder air. Even during winter, there is heat available in the outside air, despite what our bodies might tell us! A heat pump extracts that warm air from outside and moves it into your home.
Because they move heat rather than generating it, heat pumps receive high marks for energy efficiency, meaning they have a high heat output in relation to the amount energy it takes to operate them. Compared to other electric heaters, they can produce two-and-a-half to five times more heat for each unit of electricity.
Pros:
How to Choose a Heat Pump
While heat pumps are the most efficient way of using electricity to heat your home, some are more efficient than others. If you choose wisely, your heat pump can put out twice as much heat as less efficient models using the same amount of energy.
1. Choose an Energy Star qualified heat pump
The most efficient heat pumps will be labelled with the blue Energy Star sticker. A unit with this label means it will operate efficiently even at low outside temperatures, which is important for most Otago climates. To see a list of Energy Star heat pumps, check out EECA’s list here.
2. Compare efficiency with the Energy Star rating label
Energy ratings labels help compare energy efficiency between models – the more stars, the more energy efficient a heat pump is.
There are also two numbers on the label that can tell you more about the heat pump’s performance:
3. Sizing for your space
Most heat pumps in Otago are “single-split,” meaning they are standalone heat pumps designed to heat just one room or space. Unless you are installing a “multi-split” or ducted system, heat pumps are not appropriate to heat the whole house – if you simply purchase a larger heat pump thinking it will manage your whole home, you may be left in the cold holding an enormous power bill!
Although every house is different, the following calculation from Consumer NZ can help you figure out the size of heat pump you need for your space:
There are several other resources for calculating the size heat pump you need. Consumer NZ has a calculator online that incorporates more detailed information about your space, including the size of windows and number/size of uninsulated walls and other factors. Use of this calculator requires a paid membership, however for the $10 cost of a month of access, it could be a useful tool that ultimately saves you from buying an inappropriate or inadequate heat pump.
4. Use an Experienced Installer
One NZ report showed that almost 30% of heat pumps had not been installed correctly, leading to loss of performance and in some cases creating other problems! Look for an installer that:
5. Get Multiple Quotes
There can be a huge variation in pricing for the purchase and installation of heat pumps, sometimes more than $1000 for the same product. Cosy Homes strongly recommends getting multiple quotes (2 to 3).
Heat Pumps: What Not to Do
Here’s a quick list of common don’ts when it comes to heat pumps:
How to Operate a Heat Pump Effectively
A Consumer NZ survey of heat pump owners found that more than 1/3 of respondents did not understand how to use their heat pump properly. This can make an enormous difference in your power bill and your comfort.
The Eco Design Advisors of New Zealand have put together a very easy-to-use, visual guide. Follow the steps on your remote and enjoy lower power bills and a warmer room!
A heat pump is essentially a heat transfer system. It moves warm air into spaces that have colder air. Even during winter, there is heat available in the outside air, despite what our bodies might tell us! A heat pump extracts that warm air from outside and moves it into your home.
Because they move heat rather than generating it, heat pumps receive high marks for energy efficiency, meaning they have a high heat output in relation to the amount energy it takes to operate them. Compared to other electric heaters, they can produce two-and-a-half to five times more heat for each unit of electricity.
Pros:
- Generally easy to use with minor maintenance
- Good for mobility impaired or older people with no wood to chop, stack, etc.
- Heats a room quickly if appropriately sized
- Most homes can be fitted with a heat pump
- Operated by electricity, which is available to most homes in Otago
- Can also be used for cooling in summer months
- Very low fire risk
- Single heat pumps only have the capacity to heat one room or zone in a house
- The upfront capital costs of purchase and installation can be high ($3,000-$5,000)
- Not all heat pumps are created equal – a quality unit must be purchased
- As temperatures drop towards 0C, so does the performance of many heat pumps. Ensure that you’re purchasing a heat pump that is right for your climate, particularly in Central Otago
- Will not work during a power cut
- Although energy efficient, heat pumps still need to be operated correctly to be economical
How to Choose a Heat Pump
While heat pumps are the most efficient way of using electricity to heat your home, some are more efficient than others. If you choose wisely, your heat pump can put out twice as much heat as less efficient models using the same amount of energy.
1. Choose an Energy Star qualified heat pump
The most efficient heat pumps will be labelled with the blue Energy Star sticker. A unit with this label means it will operate efficiently even at low outside temperatures, which is important for most Otago climates. To see a list of Energy Star heat pumps, check out EECA’s list here.
2. Compare efficiency with the Energy Star rating label
Energy ratings labels help compare energy efficiency between models – the more stars, the more energy efficient a heat pump is.
There are also two numbers on the label that can tell you more about the heat pump’s performance:
- Capacity output – the amount of heating/cooling you’ll get from the heat pump. This is gauged using an outside temperature of 7C for heating.
- Power input – the amount of electricity the product uses (in kilowatt hours, abbreviated as kWh) to produce the hot or cold air
3. Sizing for your space
Most heat pumps in Otago are “single-split,” meaning they are standalone heat pumps designed to heat just one room or space. Unless you are installing a “multi-split” or ducted system, heat pumps are not appropriate to heat the whole house – if you simply purchase a larger heat pump thinking it will manage your whole home, you may be left in the cold holding an enormous power bill!
Although every house is different, the following calculation from Consumer NZ can help you figure out the size of heat pump you need for your space:
- Allow about 44 watts per cubic metre of room volume.
- Add another 10 percent for a large window area and another 10 to 20 percent for partial or no insulation.
- If it's a lounge, multiply by 1.5. If it's a bedroom, make it 1.2, and for other areas multiply by 0.8.
There are several other resources for calculating the size heat pump you need. Consumer NZ has a calculator online that incorporates more detailed information about your space, including the size of windows and number/size of uninsulated walls and other factors. Use of this calculator requires a paid membership, however for the $10 cost of a month of access, it could be a useful tool that ultimately saves you from buying an inappropriate or inadequate heat pump.
4. Use an Experienced Installer
One NZ report showed that almost 30% of heat pumps had not been installed correctly, leading to loss of performance and in some cases creating other problems! Look for an installer that:
- Follows EECA’s Good Practice Guide to Heat Pump Installation
- Holds an appropriate license to carry out the required electrical work
- Issues an electrical Certificate of Compliance
- Ideally holds a ‘no-loss certification’ for the handling of refrigerants
5. Get Multiple Quotes
There can be a huge variation in pricing for the purchase and installation of heat pumps, sometimes more than $1000 for the same product. Cosy Homes strongly recommends getting multiple quotes (2 to 3).
Heat Pumps: What Not to Do
Here’s a quick list of common don’ts when it comes to heat pumps:
- Don’t crank it up! Setting it to the maximum won’t make your room heat up any faster, and it will cost you heaps more. Running a heat pump at 26C uses 50% MORE energy than running it at 21C. Setting it between 20C-22C is best.
- Don’t use the Auto mode! The heat pump will try to achieve the set temperature by moving between hot air and cold air, wasting lots of energy and occasionally blowing cold air. Use the heat mode with the fan on auto setting.
- Don’t aim the louvers across the middle of the room! Heat rises – set the louvers so the air blows down and across the room. As it rises it will warm up the room.
- Don’t forget to vacuum the filter! You should vacuum the filter on your indoor unit once a month, or every two weeks if you’re using the heat pump heavily, like in winter.
- Don’t leave the heat pump on all day! If you’re home all day, or you have a very well insulated, air tight home, it’s OK to run the heat pump most of the time. But for most of us, it’s better to use the timer to start your heat pump 30 minutes before you’ll occupy the room.
- Don’t make the heat pump work too hard! Close your curtains before the last sunlight is gone, close doors and windows to the room, and use draught stoppers at doors where necessary.
How to Operate a Heat Pump Effectively
A Consumer NZ survey of heat pump owners found that more than 1/3 of respondents did not understand how to use their heat pump properly. This can make an enormous difference in your power bill and your comfort.
The Eco Design Advisors of New Zealand have put together a very easy-to-use, visual guide. Follow the steps on your remote and enjoy lower power bills and a warmer room!