How to choose a heat pump

Heating & Cooling Capacity

The most important factor in choosing the right heat pump for your room is choosing the right capacity, or heat pump size. The heat pump must be powerful enough to heat or cool the room sufficiently, otherwise the unit will run flat out constantly, and struggle to get the room to temperature. This will result in high running cost and frequent defrost cycles on the colder nights and mornings.

It is also important not to install a unit too big for the area other wise it will be draughty, noisy, be turning on and off all the time, give you an uneven room temperature and generally be annoying.

Choosing an oversized heat pump for a living area and hoping to heat the entire house is not effective in most situations. Certain home layouts can benefit from a small amount heat flow to other rooms, but the location and capacity of the unit must be carefully considered. Heat pumps are generally not suitable for use with heat transfer systems.

We can help with calculating and selecting the right size unit for your home.

Heat Pump Location

The location of the heat pump can make a big difference in the effectiveness and unobtrusiveness of the unit. Heat pumps should not be installed above or directly facing couches as the people sitting on the couch may find the airflow, and/or sound annoying. Direction of the airflow can be controlled via the remote setting, but they generally are most effective on “swing” mode, where the air is distributed in all directions via motorised louvres.

If your room is a long, narrow room, the heat pump should be on the short wall, facing the length of the room is possible. If the heat pump can be installed facing a hallway, or doors to other rooms, you may benefit from some flow on heat, but we would need to advise you on this.

Heat pumps are easiest to install on an external wall. It is sometimes possible to install them on an internal wall (a wall dividing 2 rooms), although it is usually a more involved and costly process.

Type of heat pump system

There are 3 main types of heat pump systems that are most popular in NZ homes – high wall heat pumps, floor console heat pumps, ducted heat pumps. Ceiling cassettes and ceiling consoles are not common in residential situations

High Wall Heat pumps

These are the most popular. They are the most economical to purchase, simplest to install, and do not take up valuable floor or furniture space as they are mounted high on the wall, just below the ceiling. They all come with a range of functions, such as timers, directional louvres and purifying air filters.

Floor Console Heat Pumps

Slightly more expensive to purchase than high wall heat pumps, floor consoles operate in a very similar way to high walls. Most of the functions available on high walls are available on floor consoles. A floor console can often be installed in homes that cannot accommodate a high wall, such as homes with tall glass windows. Floor consoles are good for replacing fixed gas heaters or night store heaters as they can cover the space left by the old heater eliminating the need for plastering and painting. If your home has wooden floors with access underneath, a floor console can be installed in almost any location, as pipes and cables can be hidden beneath the floor.

Ducted Heat Pumps

Often referred to as “central heating” or “ducted air con” a ducted heat pump is a good option for multiple rooms. The indoor unit is installed in the ceiling cavity or underneath the house, and a number of outlets and inlets are installed in the rooms to he heated/cooled. Desired temperature, modes and timers can be set via a digital wall controller. Ducted heat pumps are generally used to treat the multiple rooms as one zone, or one temperature. Zoning systems can be integrated into the heat pump, but are expensive.

Heating or Cooling?

Whether the unit is to be used for heating or cooling will have an effect on the capacity required. A heat pump that can effectively heat a room may not necessarily be sufficient to cool the room. Number of factors must be considered when sizing a heat pump and we can help you with this

Energy Efficiency

Most modern heat pumps are very, very efficient. A leading brand heat pump can be ¼ of the running cost of an electric oil, panel or bar heater, and around ½ the running cost of a gas heater.

The efficiency of heat pumps can be determined by the COP (co-efficient of performance), and EER (energy efficiency ratio). This number is basically dollars in vs heat out. For example if a heat pump has a COP of 4.27, this means $1 electricity equates to $4.27 heat. Compare that to an oil heater where $1 electricity gets you $1 heat.