Who makes a condensing tankless unit of 99% eficiency. I did not know any condensing are made . Rinnai and Takagi have very high out put units for heating and HW . Takagi has a 180000 BTU model 83%. Rinnai has higher BTU models with the highest efficiency I`ve seen yet, perhaps
88%.Hamilton Engineering EVO 99 series
Sit down though. The $$$ is several thousand. We sold one as a package with one of our chiller units. Our chiller was used with an air handler unit to cool a work facility. During the cold months, the chiller was switched off and the EVO was turned on to circulate its hot water through the air handler. Presto, they had heat....and a pretty darn good amount of it. That Takagi model is about $700 - $750 depending on who you know, the EVO is close to 7 times that.
ReRe