Hope Deepblue has successfully developed a condensate low NOx vacuum hot water boiler, whose efficiency can reach 104%. Condensate vacuum hot water boiler adds a Exhaust condenser on standard vacuum hot water boiler to recycle the sensible heat from exhaust gas and the latent heat from water vapour, so it can reduce the Exhaust emission temperature and recycle the heat to heat the circulating water of boiler, improving efficiency of boiler evidently.