Heating Help

extra btu needed for indirect water heater

i am doing a boiler job with 4 apartments with 5 heating zones and one 80 gallon indirect water heater. all heating zones and the indirect will be zones with circulators. i need 225,000 net btu for the heating zones. the indirect water heater will require 140,000 net btu. i will zone with circulators and a argo control that can prioritize the indirect water heater. if i do the job this way do i still need to add the 140,000 btu to my heating zones load? thanks foy your input.

No

With that many BTU's, you'll probably be on priority for the tank for a whole 10 minutes unless all 4 showers and a dishwasher are going at full steam.

besides...

that 240k is baseed on the coldest days of the year...what 8-10 days out of a 261 day heating season...priority will do the job nicely.

do not add

You don't add the DHW to the load. It is prioritized over heating. Make sure you size the circulator and HX loop accordingly. To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"