Designing a domestic hot water recirculation system is not typically difficult. which is to overcome the heat loss in the pipe between the water. Hi, I have a question regarding domestic circulation pipe sizing. I sized the main return pipe to keep velocity under 4 ft/s, but what about the. Technical guidelines on the sizing of DHW circulation systems. 6. DIN Codes of . Pressure drop of the non- return valve as per manufacturer's data. [mbar]. Q Heat loss from hot water pipes in the straight-through line. [W]. Q. I have never sized a circulating pump based on velocity, mainly because they never approach the upper limit. This uncertainty can lead to over-sizing the pump. Try the Pipe sizing hot water activity. Stay tuned, and in the meantime check out our previous blogs on this topic and our video:. Close Reply To This Thread Posting in the Eng-Tips forums is a member-only feature. Thank you for helping keep Eng-Tips Forums free from inappropriate posts. We have replaced a great amount of Swiss cheesed copper recircs. Reply To This Thread Posting in the Eng-Tips forums is a member-only feature. Leave a Reply Cancel reply Enter your comment here Online casino model you are interested in conserving water and getting hot water to your faucet quickly, the main would be closer. Note each of the pipe sections. Remember, the values listed here are per ft. The friction loss for this diameter supply pipe will be about 1. MP To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor". I'd talk to his boss since what he's requiring makes no sense to me. Mad Dog To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor".