Could anyone help me understand the calculation for the minimum efficiency of
gas storage water heaters per the table above?
The calculation is 80%Et (Q/800+110 SqRt V) SL, Btuh.
I understand that Q is the nameplate input rate in Btuh and V is the volume.
Do I use the volume of the whole system, the storage tank only or the recovery
rate volume?
I understand SL is the standby loss. Does SL, Btuh mean multiply the equation
in parenthesis by the standby loss in btu's per hour?
Thanks for the help,
Paul Diglio
I expect the natural followup is "how do I put this (SL) into eQuest?"
Attached thread spells out how you start with SL and arrive at UA. Also
includes an example with the electric heater equation.
~Nick
NICK CATON, P.E.