How do heat pumps work?

How do heat pumps work?

Heat pumps circulate air around your room using a fan. As the air passes across the pipework within the indoor unit, the pipes will heat or cool the air and pump it back into your room. Heat pumps have a controller. This can be either a wireless remote style controller or a wired controller (fixed to your wall). Different brands offer different levels of control. Some manufacturers offer wi-fi which allows you to control your heat pump while you’re away from home (or from bed!).

They generally have a few modes to choose from; heating, cooling, auto or fan. They only work in one mode at a time. This applies to ducted systems too: You cannot have it heating in one room, while actively cooling in another. If you're finding it too drafty, the fan can be adjusted to a slower speed or the louvres can be redirected (on single split systems). This may affect the ability of the heat pump to evenly distribute the warmed/cooled air.

The extreme climate of New Zealand can definitely test your heat pump. When frosty weather arrives, you may notice your heat pump is working harder than usual. We sell the best brands for New Zealand’s tough weather.

Energywise offers plenty of information on their website. There you will find further information on selecting the right model for your climate, energy efficiency, types of heat pumps, how to use them and more. Or you can read Our tips for a comfortable home to make the most of your system.

Moisture in your home

While your heat pump is in cooling mode, it will extract moisture from the air in your home. Some models offer a ‘Dry’ mode which focuses on extracting moisture from your air and reducing the humidity in your home.

Energy Saving Functions

Most brands offer functions such as Human Sensor and Economy Mode. Human Sensor detects movement in the room and instructs the unit to reduce the fan speed when there is nobody there. Using the timer functionality will improve efficiency. Wall controllers can offer 7 day programmable timers allowing off/on schedules for each day of the week.

Inverter Technology

Inverter technology allows the heat pump to alter its power as it approaches the set point. This allows it to increase power when under demand and reduce power when maintaining a set temperature. This improves comfort and cost effectiveness.


When outside temperatures get cold, your heat pump will run through a ‘defrost’ function. It is designed to thaw the outdoor unit and will run for a short period of time (perhaps 5 minutes). You may notice the heat output ceases, a flashing LED on the indoor unit and popping/gassing noises as it runs through this cycle.