Choosing a Smart Heat Pump or Air Conditioner

Reverse cycle air conditioners (otherwise known as heat pumps) are the most efficient form of heating available on the market. They will not only keep you warm in winter but also cool on a hot summer day.

In New Zealand heat pumps are often used for heating because of their high energy efficiency, compared to a conventional electric heater.

The best heat pumps can produce a great deal of cold or hot air with
relatively small energy input. For example, an electric heater will use
1kW of electricity to produce 1kW of heat. A 6-star heat pump will
use 1kW of electricity to produce about 5kW of heat. This is energy
efficiency at its best.

So you can keep warm and save money - if you replace your electric
heater with a 6 star heat pump, your cost of heating could go down
from $100 a month to $20 a month.

A 4-star heat pump will not perform as well as a 6-star one, however
it will still be far more efficient than conventional electric heaters.
However some heat pumps won’t work in winter – a heat pump may
not perform on a cold night. If you live in a place that regularly drops
below 2 degrees celsius outside in winter, ask your retailer how the heat pump will perform.

Also check the air conditioner/heat pump energy rating label carefully before you buy. These labels have recently improved to explain how well the heat pump works at 2 degrees – this is the heat output figure you need to use when sizing the heat pump.

Sizing your heat pump

Like any heater you will need a heat pump that is suitable for your
house. Correct sizing of a heat pump will ensure you get adequate
heating in winter. There are simple ways to calculate what size heat
pump you will require and your supplier should be trained to do this for you.

The following table lists one common sizing method used by suppliers:

	Area sizing method
Non insulated house	150W/sq metre
Well insulated house	120W/sq metre

 

For example if you need a heat pump for a lounge that is 40 sq metres in a noninsulated house, heating output of your heat pump can be calculated as 150 x 40 = 6000 Watts (6kW).

Compared to that, a well insulated lounge of the same area would
require a 4.8kW heat pump. You would then check the label and
make sure the heating capacity at 2 degrees celsius is 4.80 kW, to ensure your heat pump will work on a cold night.

To compare models you can check them out on www.energyrating.gov.au for star ratings and energy efficiency.

This is just an illustrative example and it is important for you to make sure your supplier is aware of the area and condition of your home, and the areas you need heat, so they can provide the heat pump that is the right size for you.

ENERGY STAR helps you choose the very best
Soon you will see the ENERGY STAR mark on the most energy efficient air conditioners and heat pumps. By choosing a unit with the ENERGY STAR mark you will be assured of the very best performance and maximum savings on your heating costs.