The hydronic heating systems parts used in one home will depend greatly upon the design/configuration that is suitable for the property. However, no matter what the design is, hydronic heating systems will share a few common components.
Furnace/boiler
The boiler, or more accurately, the furnace, is responsible for reheating the liquid before it is distributed throughout the house. Boilers are rated using British thermal units per hour or Btu/h for their input and/or output. A suitable furnace should be large enough to provide ample heat and should offset heat loss.
Circulating pump
The circulating pump or circulator pushes the water through the boiler and into the piping system using an electronically driven pump. Depending on the configuration of the heating system, more than one circulator may be used for different zones in the home and even for other purposes like domestic hot water.
Zone valves
In some hydronic heating system designs, multiple zones are created. But instead of using different pumps for each zone, one circulator may be used in conjunction with one zone valve for each zone. This allows the residents to control each zone using a thermostat.
Expansion tank
Water changes volume depending on the temperature. When hot, water expands, and when cooled, it contracts. The function of the expansion tank is to factor in this change in volume.
Air elimination devices
Air can adversely affect the performance of the hydronic heating system. As such, air elimination devices are used to remove air from the system and put this back to the atmosphere.
Heat distribution devices
Depending on the system design and configuration, a hydronic system in a home can use any or a combination of these: radiant floors and ceilings, kickspace heaters, baseboard convection units, radiators and fan coil units.
Heat exchangers
The function of this component is to transfer heat to the water or a different type of liquid used in the heating system.
Mixing valves
Some hydronic heating system designs require the use of some components which need water that is cooler than the water supplied by the furnace. The role of the mixing valve is to help produce water that is cooler.
System controls
Many of today’s radiant heating systems are controlled using electronic thermostats which can be programmed. These are used to control temperature and are often connected to zone valves.
Piping and insulation
Piping, which can be made out of copper, iron, steel, rubber or plastic, is used to distribute hot water. The insulation, on the other hand, helps minimise the loss of heat.
