Radiant Floor Heating:
Water underfloor heating:
Water floor heating uses low-temperature hot water as the heat medium, and radiates as the main heat transfer method to heat the room through the ground with heating pipes. It is usually composed of three parts: heat source, terminal system, and temperature control.
The normal operation of the water underfloor heating system requires only low-temperature hot water from 40°C to 60°C. There is a wide range of heat source options, such as central heating, geothermal water, sub-household wall-hung boilers, heat pump units, solar energy, etc. In particular, the popularization and application of solar energy and heat pump units ensure that floor heating realizes energy conservation and environmental protection in the true sense.
End System:
1. Low temperature hot water floor heating structure:
2. Low temperature hot water floor heating structure:
Standard Control Scheme:
Built-in adjustable water collector, manually adjust the flow balance of the water separator circuit, and the water collector can be controlled in a partition to open and close the floor heating circuit. It is recommended to reserve control cables and power cables, so that electric heating actuators and thermostats can be installed in the future to upgrade to constant temperature control in separate households or rooms.
Manifold:
Water collector: a catchment device connected to the return pipe of each heating pipe, with a built-in regulating valve that can manually open or close each branch of the floor heating.
Water distributor: A water distribution device that connects the water supply pipes of each heating pipe, and has a built-in static balancing valve that can properly adjust the flow rate of the system.
Note: The water separator is the water supply, and the water collector is the return water;
Flow pre-regulation of the manifold:
There are multiple radiant floor heating pipes of different lengths in the same radiant floor heating facility, and the flow rate of the pipes must be pre-regulated according to the pressure drop in the supply and return pipes. This helps to balance the individual circuits.
Precautions during the construction process:
Fitting Installation:
Manifolds - Accessories:
Tables:
Thermometer H25-T: Mounted at the end of the pressure balance, it is used to observe the return water temperature;
Pressure and temperature integrated meter H25-PT: Installed at the end of drainage, used to observe the inlet water pressure and temperature.
Household temperature control system:
On the basis of the standard type, a thermostat and an electric valve (or electric heating valve) are added, and the thermostat is equipped with a linkage output to control the boiler. When the room temperature reaches the set comfortable temperature, the electric valve automatically closes, which can also stop the boiler from working. On the premise of ensuring comfort, automatic control and energy-saving operation are realized.
The heating thermostat is a device that controls the heating equipment by sensing the temperature of the room through the temperature sensing device, comparing it with the set temperature value, and outputting the electrical signal.
Temperature control: refers to controlling the air temperature of the room so that the room reaches the set comfortable temperature.
Temperature limiting: refers to limiting the ground temperature to prevent the impact of excessive ground temperature on the comfort of residents.
Built-in temperature control: The product itself has a sensor to measure and control the air temperature in the room, at this time, the external sensor is invalid (no or not connected), which is what we usually call "single temperature control", which is suitable for the application of water heating system.
External temperature control: It is an external sensor (ground probe) to measure and control the ground temperature, which is also a kind of "single temperature control", which is suitable for the application of electric heating systems.
Internal control and external limit: It means that the thermostat has two independent measurement and control circuits, and the external temperature limit is still effective while the built-in temperature control, and the air temperature and ground temperature, any thermostat that reaches the set temperature will stop heating.
Description of the sub-room temperature control system:
The central controller of the chamber constant temperature can be referred to as the centralized control (line) box. It is applied to the intelligent floor heating control system, and the electronic control valve of the branch of the water collector in the floor heating water system is connected with the thermostat of each room for central control processing. The heat source of the system, the wall-hung boiler and the pressurized circulating water pump can be controlled by linkage. There are two kinds of centralized control boxes: wired and wireless, and this article introduces the wired method. Wireless multi-channel junction box, ideal for system upgrades.
Wiring method --- central controller:
The total current of the thermostat, electric actuator, and water pump connected to the central controller shall not exceed 4A, and the maximum current of a single output port shall not exceed 3A. The maximum current carrying capacity of the boiler linkage passive contact shall not be greater than 3A.
Auxiliary interfaces for water pumps and boilers, applications that do not affect other functions if not used. If you need boiler linkage, be sure to choose a boiler with a "linkage interface" function. The water pump is directly powered by the water pump linkage interface (power less than 100W).
Central controller --- linkage:
H-box2.. Auxiliary control output ports with two linkages:
1) Output port 1: boiler linkage control, which is a passive normally open contact switch (bearing capacity 3A), with a delay of 2 minutes.
2) Output port 2: Booster water pump linkage control, output maximum load current 3A for AC230V power supply, with a delay of 2 minutes.
3) Linkage relationship: if there is a heating demand in any room (the electric actuator is gradually turned on), the pump and the boiler will be delayed for 2 minutes, and the pump and the boiler will stop working immediately when the heating in the last room is stopped (the electric actuator is gradually turned off). The linkage of the boiler and the water pump is synchronized, that is, it starts and stops at the same time.
Hydraulically balanced bypass valve:
Mixed water cooling system:
The new water mixing system makes it economical and convenient to control the individual temperature of the heating system. It allows radiant floor heating and radiator heating to share a high-temperature heat source, eliminating the need to create a separate low-temperature heat source for underfloor heating.
The so-called "mixed water" is to mix the primary water (heat source water or high temperature medium) with the secondary water (floor heating water or low temperature medium) in proportion to achieve the purpose of cooling and constant temperature.
Principle of Floor Heating Water Mixing System:
Combined application of water mixing and manifold:
How the Mixing Center Works:
Water mixing is achieved by changing the water supply temperature to control the reasonable supply of heat, and the high-temperature hot water output of the wall-hung boiler is mixed in proportion to the low-temperature return water of the floor heating. The flow of water at these two different temperatures is the same
The water temperature is proportional to the mixed output, which determines the water supply temperature and flow rate output from the mixing center to the floor heating system.
If we know the flow rate and temperature of the two waters, then the water temperature after mixing can be calculated by the following formula:
T (Mixing Water Temperature) = (High Temperature Water Temperature × Flow Rate + Low Water Temperature ×Flow Rate) ÷ (High Temperature Water Flow + Low Water Flow Rate)
T (mixing temperature) = (80×100 + 40 × 300) ÷ (100 + 300) = 50 °C
Central Hot Water Circulation:
According to the set temperature and the measured circulating water temperature, the pump is controlled to start and stop to maintain the circulating water temperature at the same temperature as the hot water tank. The purpose is that the temperature of the circulating water can be consistent with the temperature of the water tank when the hot water is used.
Heat source = solar + heat pump unit:
Heat source - solar + wall-hung boiler:
This article comes from the Internet, compiled and edited by HVAC South Press.