Can I have plants near my heat pump unit?

What and where you choose to plant items around your outside heat pump unit can have an effect on overall efficiency.

Many home owners opt to plant shrubs as a means of disguising a unit and while aesthetically this can enhance your outside area, proper consideration needs to be made so as not to affect your heat pump by causing damage or restricting the unit’s capacity to run effectively, which would then be reflected in your monthly power bill.

The space around your outside unit is important. Just as clean filters are essential, so too is the unobscured space around a unit that allows it to disperse air easily and avoids overworking.

Shrubs, grasses and perennials provide a good windbreak option, sound barrier and shading, however ensure they are far enough away so as not to interfere with the performance of the unit or any future technician servicing. Anything planted closer than 1 meter to the unit can shed leaves, twigs and other plant materials that could end up in the fins or fan casement of the unit.

Also bear in mind the growth rate of the plant in 5, 10, 15 years from now and how that would potentially impact the unit.

Tips, advice and other guidelines…

  •  A base of crushed stone or pavers around the unit will help keep the coils clean from dirt and grass, and importantly will keep the unit level. Crushed stone has the added benefit of good drainage
  • Heat Pumps should be elevated to around 10cm above ground level to keep coils clear and to allow for proper drainage
  • Take care when using a weed-eater around the unit. Debris can damage the coil, flatten the aluminium fins, and cut the thermostat wires; shorting out the transformer
  • When mowing the lawn, direct the mower away from the unit. A coil blocked with grass clippings and debris reduces the efficiency
  • Don’t stack anything on top of the unit, it can restrict air flow, and vibrations can bounce items off and into the fan compartment causing damage
  • Keep in mind future servicing of the unit by a technician and don’t grow a prized garden, plant exotic flowers or prickly flowers like Roses and Holly around it
  • If you choose to build a fence around your unit, allow enough room to service, or even a possible full replacement. A gate wide enough to fit a unit is a good idea
  • Don’t let the outdoor unit sit underneath a leaking gutter. In winter, water could drop on the top of the unit and freeze solid. This will restrict the air flow and cause the whole unit to freeze-up