If you think that “underfloor heating” simply means having warm feet while you eat breakfast, you’re on the right track — but there’s much more to it. Here you’ll find a practical, comprehensive guide with just the right touch of irony to keep you awake while talking about pipes, screeds, and climate curves. Ready? Put on your (warm) slippers.
What is it (in plain words)
Underfloor heating is a system that distributes heat from the bottom up: instead of heating the air with a radiator, you heat the large surface of the floor, which radiates warmth to people and objects. There are two main families:
Hydronic (water-based): pipes under the floor with hot water circulating, connected to a boiler, heat pump, or other generator.
Electric: resistive cables or mats under the flooring that heat up when current passes through.
How it works (short and painless)
In the hydronic system, hot water (at low temperature) flows through serpentine-arranged pipes; a manifold distributes supply and return flows to different zones. In the electric system, resistors are distributed under the screed or directly under the tile. In both cases, the floor becomes a large “radiant plate.”
Advantages (for those who love comfort and hate ugly radiators)
Even comfort: no cold spots or “drafts”; the heat is uniform.
Efficiency at low temperatures: pairs perfectly with heat pumps and renewable sources.
Aesthetics: walls free from radiators = happy interior design.
Air quality: less forced convection → less dust circulating (ideal for allergy sufferers).
Zoning: each room can have its own management.
Disadvantages (for those who love rushed decisions)
Thermal inertia: heats up and cools down more slowly than radiators. You need to plan: it’s not suitable for those who turn it on and off “on the fly.”
Retrofit intervention: can increase the floor height (screed), so you need to assess thresholds/doors.
Initial cost: generally higher than individual radiators (but it depends a lot on the project and energy source).
Problems with unsuitable floors: some coverings reduce efficiency.
Hydronic vs Electric — which to choose?
Hydronic (water-based)
Ideal for: new builds, major renovations, integration with heat pumps or solar thermal systems.
Pros: lower operating costs if paired with low-cost sources; perfect for large areas; higher property value.
Cons: more complex installation; requires screed and thermal design.
Electric
Ideal for: small rooms, bathrooms, quick renovations where raising the floor much is unthinkable.
Pros: simpler and faster installation; great for limited areas; lower initial costs in many cases.
Cons: higher operating costs if used as the only source on large surfaces; less “green” if the electricity isn’t from renewables.
When is it worth installing (and when to think twice)
Choose underfloor heating if:
you’re building from scratch or doing a major renovation;
you want maximum efficiency paired with a heat pump or solar;
you’re looking for uniform and clean comfort;
you can allow for a slight increase in floor thickness.
Consider alternatives or hybrid solutions if:
you have very tight floor height constraints;
you mainly use rooms that need to heat/cool in a few minutes (e.g., rooms used occasionally);
you’re forced to choose coverings with high thermal resistance (thick carpet, some solid woods).
Design and sizing: it’s not magic, it’s useful math
A good system starts from real calculations:
Thermal load of the room (actual heat loss).
Areas to cover and pipe layout (spacing between pipes — typically 10–20 cm, depending on required power).
Supply temperature: for modern systems, low temperatures are used (ideally 25–45 °C).
Type of screed (traditional or dry) and thickness (affects thermal inertia).
Manifold and thermostatic valves to control each zone.
Important: do not oversize the specific power. The system works better if designed for low temperatures and long duration.
Floors and coverings: the pair that decides the result
Tiles and stone are excellent: high thermal conductivity → quick response and excellent output.
Wood: possible, prefer engineered woods and not excessive thickness; keep moderate surface temperatures to avoid stress.
Carpet/thick rugs: not recommended or should be evaluated for their insulating effect, which reduces efficiency.
Practical rule: choose materials with low surface thermal resistance.
Control and regulation: the brain of the system
Zone chronothermostats: each room with its own climate identity.
Floor probe + room probe: to avoid distorting the thermal axis by reading only the floor.
Climate curves and integration with heat pump management (if present) to maximize efficiency.
Good control reduces consumption and improves comfort: don’t underestimate it.
Installation: what to expect (main steps)
Thermal insulation under the screed (essential).
Install vapor barrier if necessary.
Pipes (for hydronic) or resistive mats (electric) fixed on panel.
Manifold and hydraulic connections.
Laying the screed (thickness varies by project).
Screed curing time and testing (pressurization, leak test).
Final floor installation.
Start-up and calibration.
Ironic note: if someone suggests walking on the fresh screed to “test stability,” thank them and ask for another technician.
Maintenance and lifespan
Hydronic: low frequency but requires checks on pressure, pumps, possible antifreeze, seals. A professional check every 2–3 years is recommended.
Electric: less “mechanical” maintenance, but operational and insulation checks are useful.
Both: monitoring and servicing prevent serious failures.
Classic mistakes to avoid (if you want to sleep soundly)
No insulation under the screed → chilling heat loss.
Pipes too far apart → cold spots.
Supply temperature too high → inefficiency and discomfort.
Laying parquet not suitable for underfloor heating.
Skipping the leak test and screed curing.
Integration with heat pumps and renewables
Underfloor heating is the best friend of the heat pump: it works at low temperatures and maximizes its COP. Pairing with photovoltaic (for electric or for heat pump) also improves energy bills. If you have solar thermal, consider integrating it for DHW (domestic hot water).
When is it better than radiators?
If you want stable comfort throughout the house and plan for low supply temperatures → underfloor.
If you need to quickly heat occasional rooms → radiators (or hybrid integration).
Often the best choice is to design the system as a whole: it’s not a “one or the other” contest but a matter of smart combination.
Recommended 8-step path (practical and panic-free)
Site inspection and energy diagnosis.
Calculation of actual thermal loads.
Choice between hydronic and electric (or mixed solutions).
Circuit design and definition of materials.
Choice of heat source (heat pump recommended).
Professional installation and leak test.
Curing and commissioning with calibration.
Maintenance and monitoring plan.
Quick FAQ (for those in a hurry)
Does it really provide a lot of energy?
Yes, but it works better at low temperatures: the “output” depends on the heat source.
Can it be installed in a renovation without raising the floor too much?
Yes, with “dry” or low-profile systems, but a technical assessment is required.
How long does it take to feel the heat?
It depends: inertia is greater than radiators. Expect longer response times but more stable comfort.
Is it suitable for all types of flooring?
Technically yes, but some coverings require attention (very thick solid wood or thick carpet reduce effectiveness).
Conclusion (serious + ironic)
Underfloor heating is a quality choice: it gives uniform comfort, increases property value, and works great with low-temperature technologies. It’s not a magic wand — you need design, insulation, the right materials, and a good installation team — but if done right, you’ll forget about radiators and never want to go back.
If you want, Gruppo Impianti Ristrutturazioni can take care of inspection, calculations, design, and installation: we’ll prepare a tailored quote, a list of recommended materials, and a clear timeline — without boring terminology, but with plenty of practical sense (and a few jokes to keep spirits high during pipe runs). Do you want the inspection checklist in PDF or would you prefer a technical consultation for your home/office right away?
