ÖNORM EN 303-5

This standard applies to heating boilers up to a nominal heat output of 300 kW which are designed for the buming of solid fuels only and are operated according to the instructions of the boiler manufacturer either with negative pressure or with positive pressure in the combustion chamber. Solid fuels in this standard are: (a) biogenic types of fuel: wood in natural state in form of A - log wood with water content W C 25 %; B1 - chipped wood (wood chipped by machine with and without bark, usually up to a maximum length o f 15 cm) water content from W 15 % to C 35 %; B2 - chipped wood as under 61, except W > 35 %; C - compressed wood (briquettes and pellets without binding agents, made of wood andlor bark particles; pemitted are natural binding agents such as molasses, vegetable paraffins and starch); D - sawdust W > 20 % to 50 %; (b) fossil types of fuel: a - bituminous coal; b - brown coal; C - coke; d - anthracite. The boilers can be used with natural draught or forced draught. The stoking can be manual or automatic. The regulations of this standard apply to heating boilers which are to be tested on an accepted boiler test stand. Heating boilers in accordance with this standard are designed for central heating installations whose heat carrier is water and whose maximum allowable operating ternperature is 100 "C and which can operate at a maximum allowable operating pressure of 6 bar. For heating boilers with a built-in or attached water heater (storage or continuous flow heater) this standard only applies to those park of the water heater which are necessarily subject to the operating conditions of the heating boiler (heating part). The standard does not apply to - central heating boilers and other heating appliances which do not have minimurn heat loss within the requirements of the standard and which are also designed for the direct heating of the place of installation; - cooking appli (...abbreviated)