Underfloor Heating Types: Hydronic, Electric Cable, or Infrared — Which to Choose
Hydronic, electric cable, mats, or infrared film: which costs less to install, which costs less to run, and where each one belongs. Comparison table and common mistakes.
Underfloor heating isn’t a decorative upgrade — it’s an engineering system that determines how a building is heated for the next 15–20 years, since switching systems after the finish flooring and tile go down is essentially impossible without demolition. The difference between hydronic, electric, and infrared floor heating isn’t just price: it’s what you can put on top, how many centimeters the screed adds to floor height, and what a kilowatt-hour of heat costs through the season. Here’s a breakdown of all three technologies and what to lock into the spec when ordering a system from China.
Hydronic (water-based) underfloor heating
A network of pipes (typically PE-RT or PEX cross-linked polyethylene, 16–20 mm diameter) laid in a serpentine or spiral pattern inside a screed and connected to a manifold that circulates water heated by a boiler or heat pump.
- Screed thickness: at least 5 cm above the pipe when laid on grade or on lower floors, or 3–4 cm with a lightweight polystyrene panel system on an upper-floor slab, where pipes sit in routed panels without a wet screed.
- Pipe spacing: 10–15 cm along exterior walls and in bathrooms (higher heat loss), 15–20 cm elsewhere.
- Pros: the lowest running cost of the three where a boiler or central heat source already exists — 3–5 times cheaper than direct electric; slow, even heat that doesn’t dry out the air; works under any finish flooring, including porcelain tile and stone.
- Cons: needs a boiler, water heater, or heat pump — a dedicated heat source; connecting to a shared central-heating riser in an apartment is typically prohibited by code; wet, slow installation — the screed needs 28 days to cure before finish flooring goes down; a leak means opening up the screed to repair.
- What to lock into the spec: pipe material and oxygen-barrier class (PE-RT with an EVOH barrier against oxygen diffusion into the loop), working pressure rating (at least 6–8 bar), spacing of the reinforcing mesh under the pipe, a manifold with flow meters on each loop for balancing.
Electric underfloor heating: cable and mats
Resistive or twin-conductor heating cable, either installed loose in the screed as a cable kit or pre-woven onto a mesh as a heating mat.
- Cable kit: screed layer over the cable is 3–5 cm; the 15–20 W/m rating of the cable itself converts to roughly 100–180 W/m² of floor area depending on spacing. Suits irregularly shaped rooms and works as primary heating, not just floor warming.
- Heating mat: thinner cable (2.5–3 mm) already fixed to a mesh at a set spacing — goes straight into tile adhesive with no screed, adding only a few millimeters to floor height. The standard choice for bathroom or balcony renovations where you can’t tear out the existing screed.
- Pros: simple installation with no wet trades (mats) or a minimal screed (cable); a precise thermostat with a floor sensor holds temperature tightly; no dedicated heat source needed — just a properly rated electrical circuit.
- Cons: the highest running cost of the three — direct electric resistance heating; needs its own circuit and RCD protection; under laminate or engineered wood, only with the thermostat capped at 27–28°C, or the flooring dries out and cracks.
- What to lock into the spec: cable resistance and the declared wattage per meter (a mismatch against the datasheet is a common substitution), twin-conductor cable (no electromagnetic field, costs more than single-conductor but safer for bedrooms), certification on the thermostat and floor sensor.
Infrared underfloor heating (film)
Carbon or bimetallic heating strips laminated between layers of polyester film about 0.3–0.4 mm thick. It heats surfaces and objects directly through infrared radiation — closer to sunlight than to convection.
- Pros: the thinnest installation of any system — no screed, goes straight under laminate, carpet, or engineered wood on an underlayment; reaches comfortable temperature in minutes rather than the hours a hydronic system needs; can be cut to size and installed locally — just under a sofa or a bed, not across the whole room.
- Cons: under tile or porcelain, needs an added levelling underlayment and reinforcing mesh over the film, or the tile cracks under point loads without a rigid base; less durable in wet areas without properly sealed connections; at high output, some laminate finishes can dry out on the surface.
- What to lock into the spec: strip wattage (typically 220 W/m² for carbon film), roll width (50, 80, 100 cm — to cut a room with minimal waste), copper bus bars along the film edges (not bare contact points — the usual cause of local hot spots and breaks), moisture-rating certification for zones near sinks.
Comparison: which type fits your project
| Type | Installation thickness | Running cost | What goes on top | Best for |
|---|---|---|---|---|
| Hydronic | 3–5 cm (screed) | Low (needs a boiler) | Tile, stone, porcelain | Houses with a boiler, large areas |
| Electric cable | 3–5 cm (screed) | High | Tile; laminate with limits | Bathrooms, kitchens, irregular rooms |
| Electric mats | A few mm (in adhesive) | High | Tile, porcelain | Renovations without removing the screed, balconies |
| IR film | No screed (under underlayment) | Medium-high | Laminate, carpet, engineered wood; tile with underlayment | Spot heating, apartments, bedrooms |
Mini-case: why hydronic heating didn’t work out in an apartment
A client renovating an apartment in a multi-unit building wanted hydronic underfloor heating throughout, based on the low running cost a friend was getting in a private house. When the plan went to the building management company, it turned out that connecting to the shared central-heating riser wasn’t allowed — water returning from the floor loop comes back cooler and throws off the temperature balance for other units on the same riser. Installing a separate electric water heater just for the floor heating didn’t pencil out for the load involved. The project was reworked to electric mats in the bathrooms and kitchen and IR film under laminate in the bedrooms and living room — the electricity bill went up, but the plan was approved and installed without touching load-bearing structures.
Sourcing underfloor heating systems from China through Dream View
Dream View is a sourcing agent with a fixed 10% commission on order value. For any type of underfloor heating, we lock the pipe diameter and barrier class or cable resistance, the width and wattage of IR film, and thermostat certifications into the spec — then verify those exact parameters during pre-shipment inspection to catch undersized pipe or substituted cable wattage. Sourcing heating systems directly from Chinese factories typically saves 30–40% against a local supplier at the same material grade. For the broader principles of sourcing building and finishing materials, see Sourcing Building Materials from China.
Planning a heating system and not sure which type fits your floor area and heat source? Email orders@dreamviewchina.com or submit a request on our services page — we’ll help pick the materials and quote delivered cost for free.
Frequently asked questions
Which underfloor heating is cheaper to run — hydronic or electric?
Hydronic (water-based) heating is 3–5 times cheaper to run if the building already has a gas boiler or a central heating source, because heating water costs less than direct electric resistance. Electric only wins on running cost where there is no access to a central heat source and installing a boiler is not worth it — for example, in an apartment or on a small area under 15–20 m².
Can you install electric underfloor heating under laminate or engineered wood flooring?
Yes, but only the thin option — a heating mat (3–5 mm) or infrared film — and only with the thermostat capped at 27–28°C. Cable heating set in a 3–5 cm screed is not used under laminate: the screed raises the floor level by several centimeters and can overheat wood-based flooring at peak output.
Why can't you install hydronic underfloor heating in an apartment with central heating?
In most jurisdictions, connecting hydronic underfloor heating to a shared central-heating riser is not allowed by code — it pulls temperature and pressure away from other units on the same riser. In apartments, only electric (cable, mats) or infrared underfloor heating is used; hydronic needs its own heat source — a boiler or water heater.
What is infrared underfloor heating and how does it differ from cable heating?
Infrared film heats surfaces and objects in the room directly, similar to sunlight, rather than heating the air — carbon strips laminated into a polyester film about 0.3–0.4 mm thick. Cable heating warms the air by heating the screed. IR film reaches temperature faster and installs without a screed under laminate or carpet, but pairs poorly with tile unless a levelling underlayment is used.
How thick does the screed need to be for hydronic underfloor heating?
At least 5 cm above the pipe when laid on grade or on lower floors, and 3–4 cm with a lightweight polystyrene panel system on an upper-floor slab. A screed that's too thin cracks from heating cycles and lacks thermal mass; one that's too thick slows the time to reach temperature and adds load to the slab.
What costs less to install — underfloor heating or standard radiators?
Radiators are cheaper to install upfront — pipe routing is simpler and doesn't raise the floor level. Underfloor heating costs more at the start (pipe or cable, screed, manifold or thermostat), but gives even heat without hot radiators along the walls and frees up wall space — that cost difference is usually planned for at design stage, not decided after the screed is poured.