Reverse Buffer Tank Setup
Hello, new guy here.
I am currently installing my second Hydronic Heating System in a new house I am building, (first system I installed in a garage a few years back).
I have thought and read a lot about how to best incorporate the latest in industry accepted practices and equipment into this new system.
The question I have is in regards to the use of a buffer tank with a small thermal mass condensing boiler, in my case a TT SOLO 110.
I understand the concept of the Buffer tank is to act as a thermal flywheel and to store energy and smooth out rapid temperature fluctuations / short cycling etc.
I have an idea of using a small indirect water heater (TT Mini Smart) piped into the boiler supply(return) using closely spaced tees with a check valve between. The idea being that the domestic cold water would first flow into the buffer tank, get heated to whatever temperature the remaining heat in the boiler supply/return water has left in it, and then flow into another larger DHW tank that is connected in standard fashion to the hydronic system. This (in my mind) would allow the larger DHW tank to require less input from the boiler (which in itself does not make much economical sense, only increaded capacity) however, it would also allow the return water to the Mod/Con boiler to be lowered, increasing the efficiency of the condensing aspect of the unit. I have not come accross any info or posts on this idea (although I am sure others have thought of some form of this), but would be interested in an industry professional's opinion regarding it.
I realize that the DHW usage would be inconsistent, and that return temps would vary, but they would always be lower than if the return buffer was not there.
The concept is still the same, storage of available energy. Just the components are moved around a little to affect an efficiency improvement for the boiler.
Any thoughts pro or con would be greatly appreciated.