Boiler to feed Air Handler
I am getting quotes to replace an existing conventional Williamson forced hot air gas furnace and Carrier air conditioner in Connecticut. Most contractors are recommending standard furnaces and air conditioners such as the Carrier Infinity series. One contractor is suggesting a gas fired Triangle Tube Prestige boiler. This boiler will feed some sort of a radiator installed into the ductwork above the air handler. A standard air conditioner could be installed above that. He claims that the boiler will be more efficient than a conventional high efficiency gas furnace. In addition, the boiler could feed a hot water heater and improve the efficiency of that as well.
I haven't found any discussion of using a boiler to heat a forced hot air system. Does anyone have any experience in this? Is it practical? Is a boiler more or less prone to failure than a condensing high efficency furnace such as Carrier Infinity or Trane XV?
Unless your looking for a higher water heater recovery rate.
You'll be hard pressed to get a good ROI by using a boiler with a hydro coil, over a 95, or 96% efficiecent condensing gas furnace.
Using boiler in this set up isn't unusual. But with the higher efficiency furnaces, you won't save much if any thing by using a boiler, as far as space heating.
You will see some savings on DW heating, but not enough to justify the boiler.
Check into the York and Rheem modulating furnaces.