When considering a heat pump, the same question often comes back, “Does a heat pump still work well at low outside temperatures?” This is quite understandable, because in the Netherlands we regularly experience cold nights, frost and days around freezing. In this article, we explain to you exactly how efficiency changes, why you don’t need to worry about winter performance, and how we completely unburden you when choosing and installing a heat pump.
What do we mean by the efficiency of a heat pump?
The efficiency of a heat pump is usually expressed in:
- COP (Coefficient of Performance) – the efficiency at a given time
- SCOP (Seasonal COP) – the average annual efficiency over all seasons
What exactly does COP say?
COP 4 means that for 1 kWh of electricity, you receive about 4 kWh of heat. The higher the COP, the lower your energy bill.
What does SCOP say?
SCOP looks at:
- outdoor temperature in all seasons
- moments of use
- start-up and defrost cycles
Modern air-water heat pumps often achieve a SCOP between 3.5 and 4.5, even in the Netherlands.
Why does outside temperature have so much influence?
A heat pump extracts heat from the outside air. The lower the outside temperature, the harder it becomes to extract heat. As a result, the heat pump has to work harder and its efficiency drops slightly. Nevertheless, a modern heat pump remains efficient and reliable even in freezing temperatures.
COP at different outdoor temperatures:
| Outdoor temperature | Average COP | Explanation |
| +10 °C | 4,0 – 5,0 | High efficiency, ideal conditions |
| +5 °C | 3,5 – 4,5 | Normal Dutch winter day |
| 0 °C | 2,5 – 3,5 | Still very economical compared to gas |
| -5 °C | 2,0 – 3,0 | Heat pump operates stably, slightly lower efficiency |
| -10 °C | 2,0 – 2,5 | Still operational |
| -15 °C | 1,8 – 2,3 | Modern heat pumps still function fine |
These values vary by heat pump type, home and installation quality.
Up to what outside temperature does a heat pump operate?
Many people wonder up to what temperature a heat pump works well. The good news is that this is not a problem. Air-water heat pumps typically function down to -15 °C, while modern systems even work down to -20 °C. A hybrid heat pump automatically switches to the boiler when needed. This keeps your home comfortably warm no matter the weather.
Heat pump efficiency in winter: how big is the difference?
The efficiency of a heat pump drops in winter, but not nearly as dramatically as is often thought. Even at 0 °C, a heat pump still delivers 2 to 3 times as much heat as it consumes in electricity. This keeps a heat pump:
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cheaper than gas
-
more sustainable
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stable and reliable
Why heat pumps perform better and better in cold weather
Modern heat pumps become more efficient every year due to powerful modulating compressors and improved refrigerants. Smart, economical defrost cycles and an optimized heat exchanger provide additional efficiency. High-performance monoblock and split technology further improve performance. Thanks to these innovations, heat pumps work extremely well, even in the relatively mild Dutch climate.
How does a heat pump defrost cycle work?
In humid and cold air, ice can form in the outdoor unit. The heat pump then briefly switches to a defrost cycle. You may see temporary plumes of steam or experience a brief drop in heat production. This is normal and usually lasts only a few minutes.
Hybrid heat pump: smart at low temperatures
Do you want security and savings? Then a hybrid heat pump is an excellent choice. You save up to 70% of gas. In extreme cold, the system automatically switches to the boiler. So you always enjoy high comfort and heat guarantee. Moreover, the investment is lower than with a fully all-electric heat pump.
What does this mean for your energy bill?
Even if the efficiency drops slightly in cold outdoor temperatures, a heat pump is still very attractive financially. This is because you benefit from significantly lower energy costs and a sharp reduction in your gas consumption. In addition, the energy label of your home increases, you reduce CO₂ emissions and you often qualify for attractive ISDE subsidies.
ISDE subsidy for heat pumps
Government encourages sustainability. Indicative amounts:
- Hybrid heat pump: €2,400 – €3,000
- Air-water heat pump: €2,550 – €3,750
We will, of course, help you with:
- grant advice
- required documentation
- proper placement (required for grant)
Choose a heat pump that fits your home
Our advice is to always choose a heat pump that fits your home. No two homes are the same, so it is important that the heat pump fits your situation perfectly. We pay attention to insulation values, the type of delivery system such as radiators or underfloor heating, the required capacity and your future plans, for example whether you want to completely get rid of gas. On this basis, we advise you personally and take the entire process off your hands, so that you are completely relieved.
Modern heat pumps work efficiently even at low outside temperatures. Don’t let cold weather deter you. They are designed to perform reliably, economically and quietly, even in freezing temperatures. At The Sustainable Boys, we are happy to help you with clear and honest advice. That way you will know exactly which heat pump suits your home and what you can save annually.
