Under Floor Heating Manifold can control the flow of water. It also spreads comfortable heat through the whole floor. It is like a meeting point of a heating system. It connects both the supply and returns lines of the system. A Manifold system into a solid floor with a screed is a good choice. Screed has direct contact with the heating pipes. It provides excellent heat transfer. Screed offers a flow of heat and almost zero temperature changes. It is important to ensure the products used are suitable for underfloor heating. Valve Regulation is also very much important. It is necessary to balance the valves according to instructions. It ensures the flow of water to each circuit is approximately equal.
You should follow the international standards for designing a UFH System. Some important issues are there. The problems with the Underfloor Heating System are below:
Sources of Heat: For lower flow temperatures you can consider a variety of heat sources. For example- Solar, Heat Pumps, or Geothermal.
Location of Manifold: Try to place the heating manifold near the center. It will make the installation easier.
Heat Outputs and Floor Temperatures: It is difficult to provide precise heat outputs. Most output for any UFH system on a solid floor is approximately 11 Watts/m²/K. . Here, K is the difference between the surface of the floor and the desired room temperature.
Screeds: The screed transfers the energy from the pipes to the heated area. Its thermal mass will respond to the heating demand depending on its depth and makeup. Most screeds are 65 – 75mm thick. More modern pumped screeds are good at a speed of application and curing time. You can also reduce the screed depths. This will speed up the performance of the system.
Floor Covering & Finishing: Floor covering is an essential part of the heating system. The thermal resistance will affect the floor.
Perimeter Areas: Achieving higher floor temperatures and higher outputs is possible. This may be in a vacant living space. The area covered by furniture is also applicable. It is good practice to reduce the pipe spacing to approximately 100mm.
Manifold parts & components are well known. Actuators, Pressure Gauge, Flow Meter, Mixing unit, etc., are the main parts of the manifold.
Operational Function of Heating Manifold
Suitable controls are necessary to achieve comfortable conditions. It is also needed to maintain economic operation. It also complies with Building Regulations & other Standards. Underfloor heating systems are the sole heating system. It has a great impact on other appliances like radiators. There are many ways to regulate the system. UFH is more convenient than traditional systems. It is good practice to provide controls that can “set back” the temperature in an area by 4 – 5°C. . It happens during periods of low demand, such as nighttime.
Room thermostats can control the actuator valves on the manifold. These can control the flow of water in each loop.
Controlling Flow Temperature
Water temperature might get reduced to the required temperature. It will happen when a condensing boiler with a low-temperature control is not used. You can use more advanced controllers like weather compensators & an external sensor. These will adjust flow and temperature to compensate for external conditions.
It is also essential to have a device to control the boiler and pump. It helps to prevent flow temperature from exceeding safety limits.
Room thermostats can control the air temperature in a room or area. It will enable individual pipe circuits. It will be helpful to open or close and turn the pump/boiler on or off as required. It is also possible to zone off the rooms.
There are a wide variety of room thermostats. Many of those are suitable for underfloor heating manifold systems. These include electro-mechanical, digital and programmable. Models can be hard-wired or controlled by radiofrequency.
Programmable Room Thermostats can control the system. You can set each zone with different requirements. Using a remote sensor from another room is a good technique. It will help for operating the control system with 240 Volts. The main control is for a wet area such as a shower or bathroom.
Controlling Boiler and pump
The boiler should not operate when there is no heat demand.
Heat loss Calculation of Manifold System
Heat loss calculation is a must. It can establish the amount of heat required for each room or area. The heat loss through the ground floor is generally ignored. Because the floor will be warmer than the room temperature, there will be some heat loss. 10% margin is added to the total when calculating the boiler load. You can calculate the actual heat output. It is possible by dividing the heat needed and the total floor area. Pipework is not required in permanent regions, for example, under kitchen units. In this case, excluded it from the calculation.
There is a heat loss in a room at 1200 W. The floor area is 20m². The performance of the system required is,
Heat Loss / Floor Area = Required Output (unit =W/m²)
1200W/20m² = 60W/m²
You have to provide supplementary heating if there is heat loss of greater than 100 W/m²
Manifold Position & Circuit Lengths
An ideal heating manifold is available in a 4, 8, or 12 port configuration. The pipe should be 120 meters and 150 meters. It allows the flow and returns connections to the manifold. The configuration selection for the manifold will depend upon two things. One is the number of loops of circuits. Two is the number of zones you need.
The number of circuits will depend on the size of the area. You can plan the pipe layout after determining the loop number and configuration.
To repair a manifold, you will have to look at the system pressure. You need to check various things to ensure the pumps work. Check the system interlock. Check whether each zone switches are on or not. Check if the controls are set okay and check the leaks.