How much kW do I really need? Ideally dimensioning heat pump power.
The key to performance: ideal kW sizing
Dimensioning is key. Only settle for the perfect fit.
The perfect heat pump size ensures a reliable operation and long-term comfort for your home. There's quite a range of outputs: from a few kilowatt to tens of kilowatts. A heat pump's nominal heat output shows their heating or cooling capacity under standard conditions. This makes it easy to compare different models.
What you want: An ideally sized heat pump
This ensures you:
- Optimal performance year-round
- Cost-savings at the end of the year
- Longevity for years to come
Non ideal kW sizing
What you don't want
1. An under dimensioned heat pump
- Room not properly heated
- Runs continuosly in full power
- Result: Higher bills, higher wear and tear
2. An over dimensioned heat pump
- Shuts down heating modus a lot
- Result: Higher bills, higher wear and tear
Therefore, aim to find the sweet spot for your heat pump. An experienced installer can provide you with the right pipe sizing and installation, following regulations.
How to dimension a heat pump
What influences your heat pump's power needs?
- Thermal insulation
Your building's insulation is crucial. Good wall insulation, fewer windows, and quality frames help maintain temperature. Better insulation means less heat needed.
- Room size & use
The size and volume of your rooms matter. Larger spaces need more heat for comfort. Whether it's a cosy home or a bustling commercial space also impacts the heat load.
- Solar exposure
Sunlight and weather exposure play a role. More sunlight can reduce your heat load, while exposure to elements may increase it.
- Climate conditions
Your local climate is a major factor. Average temperatures and seasonal changes must be considered.
The quick way of dimensioning a heat pump's power.
For a rough estimate, start with your room's size. Multiply the area in square metres by an insulation coefficient. This varies based on your building's insulation:
- New built buildings (good insulation): 0.035 kW/m²
- Relatively new buildings (from 1990 and newer, poor insulation): 0.07 kW/m²
- Old buildings (older than 1990, very poor insulation): 0.1 kW/m²
For example, a 100 m² apartment with average insulation needs a heat pump with around 7 kW (100 x 0.07) of thermal power. Remember, this is just a guideline. Each situation is unique and requires specific assessments and expert advice.
See the table below for an overview in average insulated buildings.
Remember: This is only a very rough estimation. For a more detailed version consult a specialised technician to find the perfect heat pump for your building and climate zone.
Overview of kw per m² (average insulation)
How many kW are needed per m² from a heat pump?
| Space size | Required Heat pump power | Heat pump |
|---|---|---|
| <80 m² | 4-6 kW | aroTHERM plus | aroTHERM pro |
| 80 m² | 6 kW | aroTHERM plus | aroTHERM pro |
| 100 m² | 7 kW | aroTHERM plus | aroTHERM pro |
| 120 m² | 8 kW | aroTHERM plus | aroTHERM pro |
| 140 m² | 9 kW | aroTHERM plus | aroTHERM pro |
| 160 m² | 10 kW | aroTHERM plus | aroTHERM pro |
| >160 m² | >10 kW | aroTHERM plus | aroTHERM perform |
Heat pump range with different kW output
Our heat pump portfolio from S to XL: all tested to the limit in 300 functional life tests.
- 1/4Air-to-water heat pumparoTHERM plusOur most efficient air/water heat pump reduces operating costs.Get more details
Efficiency in its most flexible form.
- Our most efficient air/water heat pump reduces operating costs.
- Our quietest air/water heat pump with 28 dB(A) for a peaceful neighbourhood
- Maximum freedom of positioning thanks to uniquely minimal protective zones.
- Elegant design in black grey
- Including free 5-year guarantee
The new standard: Our new aroTHERM plus heat pump always finds its place. This is because our safety concept, which is unique in the industry and minimises the necessary distances. Equipped with the natural refrigerant R290, it is our most efficient air-to-water heat pump and generates up to five parts heat* from one part electricity. Available in output sizes from 3 to 12 kW, it is ideal for one-family houses - even with existing radiators, of course.
- 2/4Air-to-Water Heat PumparoTHERM proMinimum size for maximum comfort: the aroTHERM pro with an output of 5 to 11 kW is our space-saving heat pumpGet more details
The space saver for outdoor installation
Minimum size for maximum comfort: the aroTHERM pro with an output of 5 to 11 kW is our space-saving heat pump. It is not only the ideal solution for new buildings. Due to its high flow temperatures of up to 70 °C, it is the ideal solution for modernising your heating system while keeping existing radiators. Thanks to our industry-unique safety concept to reduce protective zones, the heat pump can be placed almost anywhere. With ErP labels up to A+++ (D - A+++), it offers highly efficient heating and is also eligible for subsidies. Furthermore, its use of the natural refrigerant R290 makes it a future-proof choice.
- 3/4Air-to-Water Heat PumparoTHERM SplitA split heating solution with up to 12 kW output for larger single-family houses or multi-family houses.Get more details
A split heating solution with up to 12 kW output for larger single-family houses or multi-family houses.
- Super quiet operation
- High energy efficiency at low operational costs
- Outstanding quality and durability
- Can even be installed up to 40m away from your property
The aroTHERM Split heat pump increases your energy efficiency by using free environmental heat as its main energy source. With its output of 10 and 12 kW it is a cost-efficient heating solution for larger single-family houses or multi-family houses.
- 4/4Air-to-water heat pumparoTHERM Split plusA highly efficient split heating solution for one-family houses or energy modernisation projects.Get more details
A highly efficient split heating solution for one-family houses or energy modernisation projects.
- Low running costs due to high efficiency
- Low running costs due to high efficiency
- High heating, cooling and hot water comfort
- Flexible installation
The aroTHERM Split plus reduces energy consumption with free environmental heat. With its output from 3 kW to 7 kW it is the ideal choice for newly built one-family houses or in energy modernisation projects. And with a distance of up to 40 metres between the indoor and the outdoor units, you are also flexible in choosing the installation place.
