There are different advantages to different forms of hydronic heating. Different customers and situations may be better served with different choices.
Hydronic UnderFloor Heating
The concept is simple- Hot water is piped through the floor to heat the room. The result is efficient and successful; rooms can be kept at a pleasant temperature with lower heating costs than almost any other heating method.
The downside is that this system really should be installed while building the house. It is quite expensive to try and renovate an existing house in order to install water pipes through the concrete.
Electronic UnderFloor Heating
This has many of the advantages of floor heating – efficient heat with no drafts. It also has the advantage that is it easier to install, especially in a completed building.
A variation on this is the use of electronically heated mats. These are non-permanent and are more cost efficient than stand-alone heaters.
Wood Fired Boiler Hydronic Heating
The water in underfloor hydronics has to be heated before use. Using a wood fire to heat water is an old but popular method. The burning wood heater can be discreetly installed in a garage or basement, quietly supplying heated water; or more modern installations use a home fireplace that heats directly the room while also heating water for hydronic use. These home fireplaces have a pleasant nostalgic look.
Solar Hydronic Heating,
Solar power has been a popular option for water heating over the past generation. Using it for hydronic heating seems like the next logical step. Large quantities of water can be heated by the Sun, and used over the following days to heat the house.
Most house boilers are a wet back boiler. These expose more water to the boiler, and prove more economical.
Pellet boilers are used for larger applications. There are very suitable for loads of 3.9Kwatts or more, and work efficiently near full capacity. They are usually too large for an average home and waste energy if working at lower capacity.