What Are Underfloor Heating Manifolds?

Underfloor heating is increasingly popular in various industries. One of the key components in this system is the underfloor heating manifold. Its application can even be a strategic step to improve the quality of the work environment and operational efficiency.

What Is It?

Manifolds are important components in floor heating systems. Their primary function is to distribute hot water to various heating loops installed under the floor surface.
This device acts as a connecting point between the heating source, such as a boiler or heat pump, and the circulation of water flowing through the pipes under the floor.

Modern manifolds, like the Legom manifolds of M-B25, M-B32, M-BN25 and M-BN32 models, are made of corrosion-resistant brass or nickel-plated brass and designed for durability. They operate at up to 110 °C and 16 bar working pressure, making them suitable for industrial-scale applications. Each model comes in versions with 2–9 outlets (branches), each branch spaced 50 mm apart, and features high main pipe flow capacity (up to 12 m³/h) with branch pipe flow up to 1.5 m³/h.

In addition to distributing heat, manifolds also have several other functions. With control valves, manifolds allow adjustment of water flow to each loop, which is useful for controlling room temperature effectively. They also function as water collection points, channeling water back to the heating source after passing through the heating loops.

Floor heating systems that use manifolds can reduce energy consumption because they work with low water temperatures. The temperature throughout the room also becomes more comfortable, the work environment is tidier, and installation is simplified. In addition, manifolds like Legom’s are designed for easy installation and maintenance, reducing project time and cost.

Types of Underfloor Heating Manifolds

While most underfloor heating systems are part of a sealed (closed-loop) hydronic system, manifolds come in several configurations and feature sets. Some commonly used types on the market include:

• Standard Floor Heating Manifold
  The most common type used for hot water distribution, often equipped with manual or automatic control valves to adjust the flow to each loop.

• Floor Heating Manifold with Pump
  Equipped with a transfer pump to increase water circulation. This helps distribute hot water more effectively in larger areas or systems with many loops. (Legom’s current models do not have a built-in pump; pumps can be added separately if required.)

• 2-Pipe Type Floor Heating Manifold
  Has two pipes for water inlet and outlet, providing better control over water temperature and flow, thus increasing system efficiency.

• Modular Floor Heating Manifold
  Consists of several parts that can be arranged as needed, offering flexible sizing and configuration. Legom’s M-B25, M-B32, M-BN25 and M-BN32 manifolds are examples of modular underfloor heating manifolds—available with multiple outlet configurations for sealed hydronic systems.

• Floor Heating Manifold with Integrated Thermostat
  Some manifolds can be equipped with thermostats for automatic temperature control, increasing comfort with more precise temperature settings. (This is not a standard feature on the current Legom models.)

• Floor Heating Manifold for Multi-Zone System
  Designed to regulate several heating zones separately, allowing different temperature settings in different rooms—ideal for large buildings.

How Underfloor Heating Manifolds Work and Their Components

The operation of floor heating manifolds involves several components working together to ensure the heating system functions properly:

1. Heating Source
   The system starts with a heating source, such as a boiler, heat pump that heats water, which is then channeled to the manifold through an inlet pipe.

2. Distribution
   Once the hot water reaches the manifold, it is distributed to the various heating loops via multiple outlets connected to the pipes supplying water to each loop. Legom’s high main pipe capacity ensures balanced flow across branches.

3. Control Valves
   Inside the manifold, control valves regulate the flow of water to each heating loop. By adjusting these valves, users can control the temperature in different areas of the room as needed.

4. Return Flow
   After the hot water has flowed through the heating loops and provided heat to the floor, it cools down. The cooled water then returns to the manifold through outlet pipes. The manifold collects the cold water from all loops and flows it back to the heating source to be reheated, creating an efficient closed circulation.

5. Connectors
   Connectors are used to ensure a strong and watertight connection between the pipes and the manifold. The Legom models use F1″ × M3/4″ connections with Eurocone dimensions of 20×2.0 and 16×2.0 for secure installation.

6. Sensors and Compensators
   Some systems are equipped with temperature sensors to monitor the temperature of the flowing water, allowing the system to automatically adjust the flow and maintain desired room temperatures. Systems may also include expansion or compensating devices (such as expansion vessels) to handle changes in water volume due to temperature fluctuations and to prevent damage caused by pipe expansion or contraction.

With a good understanding of the function and types of underfloor heating manifolds—and by referencing real-world products like the Legom M-B25, M-B32, M-BN25 and M-BN32 Modular Brass Manifolds—companies can improve comfort and operational efficiency. The implementation of this system can have a significant positive impact in an industrial environment.