General heating boilers are calculated according to area. For general residential, 1 ton of boiler heating area is 6000~8000 square meters. For the common workshop and other higher places and cold areas, heating area should be relatively reduced.

Boilers are divided into fuel oil gas boilers, coal-fired boilers, biomass boilers, electric boilers. The state strictly controls the coal-fired boilers. The gas-fired boiler should consider whether it is convenient to install the gas pipeline. If it is not convenient, oil-fired or electric boilers should be considered.

Boiler should has high efficiency. The boiler output, the number of sets and other performance can adapt to the demand of heat load change, in order to facilitate economic management. If the use of one boiler operating at full load can meet the demand for steam, it is not appropriate to use two boilers operating under lower load. However, from the perspective of safety production, it is necessary to consider whether a single boiler in operation can be started quickly in a short time due to failure, so as to meet heating requirements without affecting production.

It is better to select the boilers with same capacity or combustion equipment. If different, the max limitation is two models, to decrease the problems of equipment layout and management.