22 octobre 2025

Underfloor heating: efficiency and energy stability

Underfloor heating is one of the most appreciated technologies in the HVAC industry today. It provides even heat distribution, low energy consumption, and great design flexibility. However, to achieve optimal performance, every system requires quality components and consistent hydraulic balancing.

A brief history of underfloor heating

Heating from below isn’t a modern invention. The ancient Romans used the hypocaust system to distribute warmth beneath their floors. Similarly, traditional Korean (ondol) and Chinese (kang) systems relied on circulating heat to create comfortable indoor environments. Today’s technology builds on these same principles, only with more precision and performance.

Example of Korean Ondol.

How underfloor heating works

A radiant floor system heats rooms evenly from the ground up using PEX or multilayer pipes embedded in a screed layer.
Here’s how it works:

Hot water is delivered to the supply manifold, flows through the circuits beneath the floor;
then the cold water returns to the return manifold to be reheated.

Room-by-room temperature control is handled by thermostats and electrothermal actuators.

Key advantages

Underfloor heating is synonymous with comfort and efficiency, especially in low-energy buildings. Its main benefits include:

Even temperature distribution across the floor.
Lower energy use due to low operating temperatures.
Design freedom (no visible radiators).
Compatible with renewable energy sources (solar panels, heat pumps) and smart home systems.
Less airborne dust compared to air-based systems.

These features make underfloor heating a growing standard in high-efficiency buildings. The technology keeps evolving: from hydronic systems to hybrid solutions that also provide cooling during the summer.

Essential components of an underfloor system

To operate efficiently, an underfloor heating system typically includes:

1- Heat generator: condensing boiler, heat pump, or other systems producing water at 30–40°C.
2- Manifolds: direct hot water into circuits and collect return water.
3- Pipe circuits: arranged in loops or spirals beneath the floor, allowing hot water to circulate.
4- Insulation and screed: the insulation prevents heat loss, and the screed spreads heat evenly.
5- Room thermostats: control the temperature independently in each space.

Why stainless steel manifolds matter

Among all system components, the manifold is the heart of the distribution system. It channels hot water to each circuit and balances flow based on room demand.
You’ll find different manifold types on the market, primarily differentiated by material:

Stainless steel manifolds: lightweight, durable, and ideal for high-efficiency modern systems.
Brass manifolds: solid and traditional, but heavier and prone to corrosion in some conditions.
Technical polymer manifolds: corrosion-resistant and lightweight, often used in smaller residential setups.

At Itap, we recommend our stainless steel manifolds, designed and manufactured in-house to ensure:

Mechanical strength and light weight: thanks to thin but high-performing walls.
Precise control: with valves, flow meters, and accessories that make management easy.
Long-term durability: stainless steel ensures stability even under tough conditions.

Concrete advantages

By choosing Itap stainless steel manifolds, you benefit from:

Easy system design.
Quick installation with intuitive components.
Guaranteed energy efficiency for the end user.
Certified, reliable products that add long-term value to the system.

Check out the complete technical information on our stainless steel manifolds.

Managing variable flow: the role of the differential by-pass

Modern systems are controlled by thermostats and electrothermal actuators. As circuits close off one by one (typical of variable flow systems), differential pressure increases. The consequences? Noise, wear and tear on internal components, and flow imbalances.

To prevent these issues, we recommend the Itap differential by-pass kit, a simple yet effective solution:

Factory-set valve at 25 kPa.
Direct connection between supply and return.
Releases excess pressure.
Maintains steady flow in open circuits.

This compact solution reduces malfunctions, simplifies maintenance, and ensures system continuity.

Explore the technical information of this product to learn more.

Dynamic balancing: automatic efficiency for complex systems

For larger, more complex systems with many circuits and variable flow, dynamic balancing is the smartest solution. Unlike manual setups, Itap manifolds with dynamic balancing automatically adjust to maintain steady flow in every circuit, no matter the conditions.
What this means:

For designers: easier calculations, no complex adjustments, and consistent heat distribution.
For installers: fewer on-site tweaks and long-term reliability.

Key features

Automatic flow regulation per circuit.
Stable output despite system changes.
Continuous hydraulic balancing.
Reduced excessive flow.
Even temperature distribution.

Technical parameters

Adjustable flow: 30–300 l/h.
Minimum ∆p: 17–25 kPa.
Maximum ∆p: 60 kPa.
Max noise: 25 dB(A).

See the full technical information about our manifolds with dynamic balance on website.

Underfloor heating isn’t just about distributing heat, it’s an investment in comfort, efficiency, and durability. With Itap stainless steel manifolds, dynamic balancing and our differential by-pass kit, you can deliver high-performance systems that last.

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FAQ

How does underfloor heating work?

It heats the space evenly from the floor up using PEX or multilayer pipes embedded in screed. Hot water flows through these pipes via a manifold system, warms the floor, and cycles back to the heat source.

How long should it stay on?

Continuous, modulated operation is ideal. Avoid frequent on/off cycles. This keeps the temperature stable and leverages the screed’s thermal inertia to reduce consumption and imbalances.

How long does it take to warm up?

The time needed to heat a room depends on several factors: