Most people start a heat pump conversation having already decided they want “a heat pump”, and are then surprised there are four quite different ways to do it. Each has a genuine place. Here is how we think about it when we are standing in someone’s lounge.
Hi-wall
The familiar unit mounted high on the wall. One indoor unit, one outdoor unit, one room.
Suits: a lounge or a main living area you want warm quickly, on the smallest budget.
Trade offs: it heats the room it is in, and not much beyond it. Warm air is thrown out at high level and will not travel far down a hallway or around a corner. If your house is a series of closed rooms, one hi-wall unit will make one room lovely and change very little elsewhere.
Floor mounted console
A cabinet sitting at floor level, usually against an exterior wall under a window.
Suits: rooms with no clear high wall space, sloped or raked ceilings, older houses that feel draughty at floor level, and bedrooms.
Trade offs: it takes up floor space and needs to be kept clear of furniture. It is often the more comfortable option in an older villa or bungalow, because heat rises from the floor rather than being pushed down from the ceiling, and in a bedroom the air is not blowing across the bed.
Multi split
Two or more indoor units running from a single outdoor unit.
Suits: houses where you want two or three specific rooms done, and where there is only one sensible spot for an outdoor unit.
Trade offs: one outdoor unit is tidier and often cheaper than several. The catch is that all indoor units on a multi split have to be in the same mode at the same time, so you cannot heat the lounge while cooling a bedroom. Capacity is also shared, so running every head at once gives less to each than the headline figure suggests.
Ducted
One indoor unit hidden in the roof space or under the floor, feeding every room through insulated ducting and discreet grilles.
Suits: new builds, full renovations, and anyone who wants the whole house at an even temperature rather than one warm room.
Trade offs: it is the most expensive option and the most disruptive to retrofit, and it needs adequate roof space or subfloor to run the ducting. In return, there is no box on the wall in any room, it is quieter in the living space because the fan is not in the room with you, and zoning lets you shut off parts of the house you are not using.
A few things that matter more than the type
Sizing. A unit that is too small never quite gets there on a cold morning. One that is too large short cycles, which is noisy, wears the compressor and costs more to run. Both problems are permanent once the unit is on the wall.
Where the outdoor unit goes. It needs airflow, it should not sit under a bedroom window, and near the coast it should be out of the worst of the salt. Keeping the pipe run short between indoor and outdoor units also helps efficiency.
Insulation first. If the ceiling is not insulated, the most efficient heat pump on the market is still heating a leaky box. Ceiling and underfloor insulation almost always pays back faster than upgrading to a larger unit.
So which one?
As a rough guide: one main living area on a budget points to hi-wall. An older house or a bedroom points to floor mounted. Two or three rooms with one outdoor location points to multi split. A new build, a full renovation, or wanting the entire house comfortable points to ducted.
It is worth reading independent comparisons as well as installer advice. Consumer NZ tests and rates heat pumps, and their reviews are a useful sanity check on any quote.
Come and have a look
The honest answer is that the right choice depends on your house, and it takes about ten minutes on site to work out. JP Air Con quotes free anywhere in Northland, and we will tell you if the cheaper option is the better one for your place.
Call 021 344 340 or get in touch through the contact page.