Heat Pump Efficiency | Auckland Heat Pump Installation
Heat Pump Efficiency | Auckland Heat Pump Installation

Heat Pump Efficiency

Heat Pumps are the world’s most efficient form of heating and cooling and are able to generate around 2 to 6 times more heat and cooling power as the electricity it uses. Simply put, under specific lab conditions a heat pump can uses science to convert 1 Kilowatt of electricity to 2 to 6 Kilowatts of heat or Cooling power, depending on the brand and model and model of the heat pump.
The efficiency of heat is expressed as a coefficient of performance (COP) and can range from 2 -5.7 and means the heat pump can produce 2 to 5.7 times as much heat as it uses in electricity.
The efficiency of cooling power is expressed as Energy efficiency ratio (EER) and can range from 2 to 5.8 and means the heat pump can produce 2 to 5.8 times as much cooling power as it uses in electricity.
Factors that will affect efficiency:

  • Heat Pump Size – A heat pump that is too small will work over in over – drive trying to achieve the desired temperature and runs into frosting or icing issues that reduces the efficiency. A heat pump too large will continuously cycle on and off and (1) may shorten the life of the heat pump and (2) use the more electricity during the initial start up phase.
    • General rule of thumb for older houses use 60-65Watts/m3 and 50-55 Watts/m3 for newer well insulated houses.
  • Installation placement – The outdoor unit should be placed in a location with good ventilation and have no rapidly growing plants surrounding the unit.
  • Clean Air Filters - heat pumps clean and warm the air inside the room it’s servicing and dirty filters will have a detrimental effect on the heat pumps efficiency. It is recommended to clean the filters every 6 months or more frequently after heavy use.
  • Avoid using “Auto” mode: In Auto mode, the heat pump will heat and cool the room to achieve the desired temperature. This can waste a lot of energy and we suggest choosing between heat or cooling mode when starting your heat pump.
  • Correct Settings: Choose either Heat or Cooling mode with a temperature set between 18-22 degrees Celsius. Having the temperature set outside these ranges forces the heat pump to work extra hard when it is not necessary. Heat pumps can heat a room fairly quickly and thus do not need to be set to extreme desired temperatures.
  • The ability a room and hold its temperature: When the desired temperature is reached the heat pump can dramatically increase their own efficiency by reducing its heating or cooling capacity. Therefore the ability for a room to keep the rooms temperature stable the less the heat pump has to work.
    • Factors that can help keep the temperature from changing include:
      • Level of Insulation: Typically, unless a home owner has added extra insulation in the walls, ceiling and floors, the newer the house the more insulation you can expect behinds the walls, above the ceiling and underneath the floors.
      • Draft reduction: If air is allowed to escape through cracks in the windows, ceiling or if there are large gaps in the outside cladding, the harder the heat pump must work to maintain the desired temperature. Checking seals and eliminating airflow will help maintain the desired temperature.
      • Windows – in Auckland we typically see windows are either single or double glazed. Double glazed window do a better job at keeping your desired temperature from escaping.
      • Rollerblinds vs Curtains – Typically Curtains do a better job at maintaining a rooms temperature as they are denser and normally hug the window a little better. Curtains can come as an aesthetic cost where they may not look as clean or minimalistic as roller blinds.
      • Thermal Curtains – Thermal curtains are heavier, thicker and add a little extra insulation over the windows.
      • Flooring – Carpet with underlay add a little extra insulation to the floors and helps maintain a constant temperature. Generally, consumers feel carpets helps make a room feel warmer and leads to more carpet being installed during the winter months.
      • Shutting doors and windows – keep doors and window shut to stop the air from escaping. This will help with maintaining the rooms temperature.
  • Humidity – The higher the humidity of a room the more it cost to heat or cool. This is because of the water molecules inside the air absorbs the heat as opposed to spreading it around the room. High humidity, can make people feel hot and sticky by preventing and reducing the ability for sweat to evaportate. Ventilating a room before turning on a heatpump, can help Aucklanders reduce humidity and thus reduce the power needed to either heat or cool the room.
  • Not all heat pumps are made equal: From 2009 a new Energy Rating label was introduced for all new heat pump models. A crown on top of the Energy Rating Label indicated that that heat pump is super-efficient and surpasses the 6 star rating where it supersedes it by the number of stars indicated. Star rating is the easiest way to see how efficient a heat pump is but when comparing two models with a similar star rating look at the number on right hand side of the cooling or heating energy rating. Where is says “Power input KW” it tells you how much electricity is needed to produce the maximum heat or cooling of the heat pump. This is the number that should matter the most in terms of efficiency when selecting heat pumps of the same “Capacity Output”. The lower the Power input the more efficient the heat pump will be when comparing heat pumps of the same capacity output.
  • Energy Star logo: A Blue Energy Star tells you at a glance which models are best or at the top of their efficiencies. They are awarded to the top 25% of performers in each size