Installing M2G to condensing boilers

M2G operating with Condensing Boilers

Condensing boilers work on the principle of recovering as much heat as possible of the waste heat that is normally rejected to the atmosphere from the flue of a conventional (non condensing) boiler.

This is accomplished by using an extra-large heat exchanger or sometimes two heat exchangers within the boiler, which maximises heat transfer from the burner as well as recovering useful heat which would normally be lost within the flue gases. When in condensing mode (as condensing boilers do not condense all the time) the flue gases give up their 'latent heat' which is recovered by the heat exchanger within the boiler and used to preheat the return water back to the boiler. As a result the temperature of the gases leaving the flue of a condensing boiler is lower, typically 50-60°C compared with 120-180°C in a modern non-condensing boiler. At the same time an amount of water or 'condensate' is produced.

A condensing boiler will always have a better operating efficiency than a conventional non-condensing one, due to its larger and more efficient heat exchanger. The boiler capacity must be correctly sized for the system, due to the correct delta temperature across the boiler to enable heat transfer to occur.

Due to variable system load conditions in condensing boiler applications, this will cause the boiler to "dry cycle" in the same way as non condensing boiler. In this case Sabien M2G load optimising will be fully compatible with condensing boilers. Some condensing boilers have a primary and secondary heat exchanger and therefore it is important to ensure that the M2G's digital sensors are fixed to the primary flow and return connections.

If you require any further information regarding this please call Technical Support on 0800 082 65 65