9% efficiency gain from thermal post-purge of cast iron boilers?

Roger

Thank you all for such kind remarks, and excellent to see you with your bright yellow boiler nearly complete, @HVACNUT !

Roger

EBEBRATT-Ed

Looks good. nice job.

Robert O'Brien

Weil doesn't state the water content of the WGO5 but a Peerless EC5 is 26 gallons and WBV5 is 18 gallons, based on the physical dimensions, the water content is probably in between those two numbers. Approximately 22 gallons of water times two boilers or 365 lbs of water. Assuming the boiler temp is 100F over ambient at cycle end, that's 36,520 BTU/s sitting there!

HVACNUT

https://forum.heatinghelp.com/discussion/comment/1902683#Comment_1902683

15.9 gallons for the WGO-5.

I knew they listed it because I remember checking something and finding it odd the 3 section has a larger water content than the 4 section. Same dimensions on both. The middle section on the 3 is double the depth.

hot_rod

Thermal purge into a standard indirect doesn't make a lot of sense. You will never purge much 180° into a tank sitting at 140°. The warmer the tank the slower that heat transfer, and the typical indirect tank is an inefficient HX

The key to the EK system is the plate HX. A plate HX is 5 times more efficient than a tube and shell (indirect tank) With a properly sized and pump FPHX you can get within a few 2-3° A to B side. So now you squeeze all the juice out.

As @EBEBRATT-Ed mentioned, constantly purging into a zone will cause the zone to overheat. How much? Depends on how often you thermal purge, the load, the type of heat emitter, the size of the zone you purge into, etc. Maybe that is not a concern, or maybe it is not worth it.

The EK system is carefully engineered to accomplish the task as best it can be. Put the purge BTUs where they make the most sense, in a well insulated tank at 95% efficient transfer.

If you overshoot tank temperature, legionella protection gets that much better :)

Robert O'Brien

I stand corrected, still hard to believe it's less water content than a Peerless WB as someone who has humped all of them up and down stairs many times! I looked at tech specs on website, knock a third off and it's still a lot of energy sitting there, particularly at $5/gallon!