When the additional air gets accumulated in the boiler, then that extra air gets heated up and is diffused in the atmosphere. To control this, you can install an automatic blow-down system that can control the accumulation of this additional air in the boiler. In order to improve the insulation, you can install removable bracket insulation on the valve, steam traps as well as fitting. In addition, you can insulate steam distribution and also condensate return lines. A blowdown is required to maintain the concentration of boiler of dissolved solids that is required to condition the boiler water.