Create desired climate for all weather
Heat pumps do a wonderful job of extracting warmth from outside air and delivering it inside the home. Now, as focus widens from room-by-room heating to creating a climate for the entire home, flipping those heat pumps into reverse for a cool oasis on a hot summer’s day is catching on.
The fact that heat pumps work as cooling systems is not lost on most of the world, where similar, if not the exact same, devices are used as air conditioners.
In New Zealand, though, crossing a building’s threshold and being enveloped in cool, soothing air is still a mark of the most luxurious homes.
Following that same refreshing feeling as you make your way from the kitchen through the lounge, down the hallway and to the bathroom or bedroom is a telltale sign that a ducted system is lurking somewhere, humming away quietly out of sight.
Ducted systems employ a single, large unit hidden away above the ceiling or beneath floorboards, pumping out conditioned air – warm or cold – through discreet ducts to multiple rooms.
They are the most comprehensive and typically most expensive way to set your home’s climate.
Heat pump expert Aaron Trotter, owner of New Zealand Heat Pumps, which has installers in Christchurch and Auckland, says a much more common and affordable approach is to place an additional unit in the hallway.
‘‘People are slowing making the transition to having a warm home, rather than a warm room,’’ he says.
‘‘You can have a high-wall [unit] in your hallway, set it to 18 or 19 degrees, and then you don’t have to worry if you leave the living room door open.
‘‘You don’t ever transfer heat from a living space to another area, because unless it’s a ducted system they’re just not designed to have air scavenged off. But there are a lot of ways to achieve a solution; it’s just to what degree are you achieving it?’’
Giving consumers more bang for their buck is the arrival of a new, more environmentally friendly refrigerant that Trotter says is especially well suited to heat pumps in cooling mode.
Known as R32, the refrigerant has a global warming potential less than a third of that of New Zealand’s most commonly used refrigerant, R410A, and it compresses particularly well, Trotter says.
‘‘The more efficiently you can get the gas to compress, the more efficient it is, because the compressor doesn’t have to work as hard,’’ he explains.
All heat pumps work because the refrigerant in them evaporates at a lower temperature, drawing heat from the atmosphere as it changes from liquid to gas. When functioning as a cooling system, the heat pump absorbs warmth from air inside the home, which is carried off and expelled via the outside unit. Replacing the warm air is a chilled breeze.
The effectiveness of R32 in extracting heat from the air makes it a superb choice for people who might want to cool their home in summer, Trotter says.
‘‘It can handle colder conditions and respond really well and it can handle hot conditions and respond exceptionally well,’’ he says.
‘‘We now push any product with that refrigerant, because it’s future-proofing, to a large degree.’’
Installing additional heat pumps in a home allows for a gradual widening of the comfort zone at any time of year. A premium option is to install a ducted system, which can cover multiple areas from one, powerful unit.