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The choice is based on room heat loss, available surface area, desired flow temperature, floor build-up and disruption—not a rule that one emitter type is mandatory.
Existing radiators may be retained where their output is sufficient at the design temperatures. Others can be enlarged or supplemented selectively.
Demonstration-project homes had some radiators replaced
View sourceHomes in that project received some underfloor heating
View sourceEmitter selection follows the heat-loss calculation
View sourceFind the right emitters for each room
Tell FLO about the property and current heating. A survey turns the general guidance into a room-by-room design and written quote for the complete system.
Both emitters can deliver low-temperature heat
Underfloor heating uses a large surface area, while radiators use a smaller hotter surface. Either can meet a room’s load if output is calculated at the proposed water temperatures.
The design should state flow, return and room temperature assumptions. A radiator’s familiar boiler rating cannot be used unchanged at lower temperatures.
Radiators often minimise disruption
Replacing selected radiators can be simpler than lifting finished floors and changing thresholds. Double-panel or larger models may achieve the required output.
Pipework and wall space still need checking. The right answer can differ from room to room rather than forcing one emitter throughout the house.
Underfloor heating suits planned renovation
It can be attractive in extensions, new floors and open-plan spaces where build-up and controls are designed from the start.
Response time, floor covering, manifold space and zoning should be considered. A very slow floor should not be controlled like a fast boiler radiator circuit.
Mixed systems need coordinated temperatures
Different circuits may use mixing and controls to provide their intended temperatures. The hydraulic arrangement must protect heat-pump flow and avoid unnecessary high-temperature operation.
Commissioning should balance each circuit and explain schedules so radiators and floors work together.
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Questions people also ask
Will all my radiators need replacing?+
Not necessarily. Each is checked against the room load at the proposed water temperature.
Is underfloor heating more efficient?+
Its large area can support lower water temperatures, but design, controls and the whole system determine actual efficiency.
Can upstairs use radiators and downstairs use underfloor?+
Yes, if the circuits and controls are designed and commissioned as one system.
Evidence used for this answer
Figures are explained in context and links go to the independent source. Prices, tariffs, scheme rules and standards can change, so check the source again before making a financial or technical decision.
- Energy Systems Catapult: home surveys and installation reportEvidence from 742 installations, including radiators, cylinders, survey constraints and typical installation duration.
- MCS heat-pump design standardTechnical requirements for heat loss, equipment selection, domestic hot water and system design.
- MCS domestic heat-pump guideConsumer guidance covering design, installation, controls, handover and maintenance.
- Energy Saving Trust: air source heat pumpsIndependent guidance on installation costs, running costs, suitability, radiators and household savings.