Last updated: August 2026
Heat pumps are now a mainstream heating technology for high-performance homes across Europe. But there are still two common misconceptions:
“Heat pumps don’t work in cold climates.” and “Install a heat pump and the house will automatically be efficient.” Neither is true.
Modern heat pumps can operate effectively across a wide range of European climates. But their performance depends heavily on the building, the heating system and how everything is designed to work together. A good heat pump matters.
The building it is connected to matters even more.
What does a heat pump actually do?
A heat pump moves heat rather than creating it directly. An air-to-water heat pump extracts thermal energy from the outside air and transfers that energy into water used for space heating and domestic hot water. There is usable thermal energy in outdoor air even below freezing, which is why heat pumps are widely used across northern Europe. Because the system moves heat rather than generating it directly, it can deliver several units of useful heat for each unit of electricity consumed. The exact efficiency depends on outdoor temperature, required water temperature, equipment and system design. The lower the temperature the heat pump needs to produce, the more efficiently it can generally operate.
Does it work in winter?
Yes.
Modern heat pumps operate successfully in climates considerably colder than much of western and central Europe. As outside temperatures fall, efficiency reduces and the system has to work harder. In cold, humid conditions, the outdoor unit may also periodically run a normal defrost cycle. That is why correct equipment selection and sizing matter. The objective is not to pretend climate makes no difference. It is to design the system for the climate in which the home will actually be installed.
The walls matter more than the machine
This is the central point. Put an efficient heat pump into a poorly insulated, draughty building and it still has to replace all the heat that building continuously loses. TheHouz starts from the opposite direction. First, reduce the home’s energy demand through:
- a highly insulated building envelope;
- controlled airtightness;
- carefully designed thermal junctions;
- high-performance windows and doors;
- and controlled ventilation.
Then design the climate system around the remaining demand.
Reduce heat loss first. Then size the equipment.
That allows the heat pump to operate at lower temperatures and lower loads for much of the year — exactly where heat pumps perform best.
Radiators work — and cooling is available as an option
Heat pumps are often associated with underfloor heating. But underfloor heating is not essential. TheHouz uses correctly sized low-temperature emitters designed around the calculated requirements of the home. In winter, warm water from the air-to-water heat pump provides comfortable, efficient room heating. Where optional cooling is selected, a reversible heat pump can be combined with compatible fan-assisted heating-and-cooling emitters to provide room cooling during warmer periods. That means the same hydronic system can potentially provide:
heating in winter + optional cooling in summer + domestic hot water
while the ventilation system independently manages fresh air and heat recovery.
Not every conventional radiator is suitable for cooling.
Cooling capability depends on the selected emitter, heat-pump configuration, controls and condensation-management strategy. Where cooling is required, those components are designed together as one system.
Why radiators instead of underfloor heating?
In a highly insulated home, heating demand can be low enough for correctly sized low-temperature radiators to provide the required comfort efficiently.
They also offer practical advantages:
- fast response;
- individual room control;
- straightforward maintenance;
- easy replacement or upgrading;
- and no heating circuits embedded throughout the floor.
The important question is therefore not simply:
radiators or underfloor heating?
It is whether the building envelope, heat pump, emitters and controls have been designed together.
One climate strategy for different European markets
The same basic TheHouz climate strategy can be adapted to different locations. In colder northern European markets, the priority may be efficient winter heating. In warmer regions, summer cooling may become more important. Where required, optional cooling can therefore be added through a reversible heat pump and compatible heating-and-cooling emitters rather than automatically introducing a separate air-conditioning system. The exact equipment and capacity are selected according to the home’s size, calculated heating and cooling loads, climate and customer specification.
Cooling is an optional specification, not a standard feature of every TheHouz home.
Fresh air without throwing away the heat
A high-performance airtight home also needs controlled ventilation. Depending on the selected specification, TheHouz uses mechanical ventilation with heat recovery — MVHR — to extract stale, moisture-laden air from wet areas and supply filtered fresh air to bedrooms and living spaces. Heat from the outgoing air is recovered to temper the incoming fresh air during the heating season.
The systems therefore have different jobs:
Heat pump — heating as standard, with cooling available as an option where specified.
Emitters — transfer heating, and cooling where selected, into the rooms.
MVHR — fresh air, moisture control and heat recovery.
Building envelope — reduces unwanted heat loss and heat gain.
Together, they create the home’s indoor climate.
Lower temperatures mean better efficiency
Heat pumps generally become more efficient when they do not have to produce very hot water. That is why emitter sizing matters. A correctly sized low-temperature radiator or fan-assisted emitter can provide the required room output using cooler water than a traditional high-temperature radiator system. The lower the required heating-water temperature, the easier the heat pump’s job becomes. This is why the climate system should be designed from the home’s calculated heat loss — not selected from a generic equipment list.
What about optional cooling and condensation?
Cooling needs to be designed properly.
If a surface becomes colder than the dew point of the surrounding air, moisture can condense on it.
For that reason, optional water-based cooling requires compatible emitters and appropriate controls.
Depending on the system, this can include:
- dew-point monitoring;
- minimum chilled-water temperature control;
- humidity management;
- and condensate drainage where required.
This is also why we do not simply circulate very cold water through ordinary panel radiators and call it air conditioning.
Where cooling is selected, it is engineered as part of the complete climate system.
Three ways to run a heat pump well
Keep temperatures reasonably steady
Heat pumps generally perform best maintaining comfortable conditions rather than repeatedly reheating a very cold building. A high-performance home loses heat slowly, making steady operation particularly effective.
Keep water temperatures low
The system should be commissioned to maintain comfort using the lowest practical heating-water temperature. Lower temperatures generally mean better heat-pump efficiency.
Use energy intelligently
Solar PV, battery storage, smart controls and time-of-use electricity tariffs can help shift flexible loads toward periods when electricity is locally generated or less expensive.
Domestic hot-water production, battery charging and other flexible loads can increasingly become part of one coordinated home-energy strategy.
Is a heat pump always the right choice?
No.
And that is important.
In some of the smallest, very low-energy homes, annual heating demand may be so low that the additional capital cost and complexity of an air-to-water heat pump may not always be justified.
A simpler electric heating solution can sometimes make more sense.
TheHouz therefore selects climate systems according to:
- home size;
- calculated heating demand;
- optional cooling demand where selected;
- destination climate;
- domestic hot-water requirements;
- electricity tariffs;
- selected energy package;
- and customer requirements.
The right system is sized to the home — not chosen because it is fashionable.
Heat pump + solar + battery
This is where an all-electric high-performance home becomes particularly interesting.
Depending on specification, the heat pump can operate alongside:
solar PV + battery storage + EV charging + smart energy management.
Solar can contribute to the home’s electricity demand. Battery storage can move energy between different times of the day. Smart controls can coordinate flexible loads with solar generation and electricity tariffs. But the order still matters:
Efficient building first. Efficient equipment second. Smart energy management third.
Technology should complement a high-performance building — not compensate for a poor one.
Frequently asked questions
Do heat pumps work in cold climates?
Yes. Modern heat pumps are widely used across northern Europe. Their efficiency changes as outdoor temperatures fall, which is why correct sizing and equipment selection are essential.
Can a heat pump run radiators?
Yes. Correctly sized low-temperature radiators can work very effectively with an air-to-water heat pump in a highly insulated home.
Can the same heat pump cool the home?
Yes, where cooling is selected as part of the specification.
A reversible heat pump can produce chilled water as well as heated water. When combined with compatible heating-and-cooling emitters and appropriate condensation controls, the system can provide optional room cooling during warmer periods.
Is cooling included as standard?
No.
Heating is the baseline climate function. Cooling is available as an optional specification where required and where the selected heat pump, emitters and controls are designed for cooling operation.
Can ordinary radiators provide cooling?
Generally, conventional panel radiators should not simply be used with very cold water.
Effective water-based cooling requires suitable emitters and controls designed for cooling operation.
Does optional cooling replace air conditioning?
Potentially, yes.
In a correctly designed home, a reversible heat pump with suitable heating-and-cooling emitters can provide both winter heating and summer room cooling.
Whether it can completely replace a separate air-conditioning system depends on the calculated cooling load, local climate, glazing, solar gains, humidity and required indoor conditions.
Do I need underfloor heating?
No.
Underfloor heating works well with heat pumps, but correctly designed low-temperature radiators or fan-assisted emitters can also provide excellent performance.
What does MVHR do?
MVHR is primarily the ventilation system.
It continuously removes stale and moisture-laden air, introduces filtered fresh air and recovers heat from outgoing air during the heating season.
It should not be confused with the main room heating or optional cooling system.
Are heat pumps noisy?
Modern equipment can operate at relatively low sound levels, but the specific unit and its location matter.
Outdoor-unit positioning should therefore be considered during design in relation to bedrooms, neighbouring properties, boundaries and local requirements.
Is a heat pump cheaper to run than direct electric heating?
A heat pump can deliver several units of heat for each unit of electricity consumed, giving it a substantial efficiency advantage over direct resistance heating.
Actual running costs still depend on climate, electricity prices, controls and the home’s energy demand.
Is a heat pump cheaper than gas or oil?
Not automatically in every European market.
Heat pumps are highly efficient in terms of delivered energy, but actual running costs depend on local electricity prices, alternative fuel prices and tariffs.
The principle is simple
Reduce heat loss. Control unwanted heat gain. Keep operating temperatures low. Design the emitters correctly. Ventilate intelligently. Add cooling only where it is needed. Then let the heat pump do its job.
A heat pump is an important part of a high-performance home.
But it should never be considered in isolation.
The building, heating, optional cooling, ventilation and energy controls should work as one coordinated system.
That is the TheHouz approach.