Look around, nearly all the fire tube heat exchangers on the market are a shared design manufactured by either one of two or three designs coming from overseas. Except one. Navien has designed and manufactured their own fire tube and its very different from the rest. Of course its not yet been put to the test here in North America, there are not yet thousands or even hundreds of installations in place but given the track record of the major tankless manufacturer, one might expect it to perform well. For more info on the new NFB boilers coming soon from Navien click here.
Here’s a video we shot at the 2018 AHR Expo in Chicago while visiting Navien’s booth.