• Without economizer at maximum production and water input at 70ºC:
  400 kg/h with 88% steam yield, methane consumption about 32.8 cu m/h
• With economizer at maximum production and water input at 70ºC:
  400 kg/h with 93% steam yield, methane consumption about 31 cu m/h. Smoke temperature reduced to between 80º and 100ºC.

The saving is about 1-8 cu m/h. Assuming a use of about 10 hours per day, 250 days per year, this translates into an overall savings of 4500 cu m/yr.
Ultimately, with non-continuous operation at 50% capacity, a saving of about 2250 cu m/yr can be assumed for this boiler.

This calculation was made based on normal operation of the STA 30 RE steam boiler, but usage may be improved further if a circulation pump is applied on an open pan accumulator to produce hot water or indirectly on aerothermal heating units.
The economizer was designed to be applied to generators produced by Mas Generatori di Vapore in Padua, both new and older models, without interfering with the burner or generating bothersome counterpressure in the combustion chamber.
The system does not require any maintenance except treatment of the water circulating within, which should have the same characteristics as the boiler water. The height may vary depending on the application.