DIN 4709:2011-11

DIN 4709 has been prepared at the Heating and Ventilation Standards Committee (NHRS) by Working Committee NA 041-01-68 AA "Mikro KWK Anlagen" ("Small co-generation power and heat plants"). It specifies a method for determination of the standard efficiency factor for micro-CHP appliances for domestic use for heating and production of hot water. Moreover, it specifies a test specification with different thermal strains for heating operation of installations. It specifies how the energy demand for production of hot water determined in accordance with other standards is included in a standard efficiency factor. This standard applies to micro-CHP appliances and is a type approval for the system defined by the manufacturer which does not exceed a nominal heat input of 70 kW and uses natural gas and other fuel gases as fuel in accordance with DVGW G 260 or fuel oil in accordance with DIN 51603-1. This standard applies to micro-CHP appliances which are defined as a unit by the manufacturer.