Domestic Hot Water Return

In a traditional hot water recirculating system there is a dedicated return line for the hot water pipes which runs from the furthest bathroom or fixture back to the water heater.

Domestic hot water return. Water flow velocity is very important in domestic hot water pipes with copper piping and brass or copper alloy valves. Domestic hot water return piping is used in applications where the occupants need or desire to have hot water available right at the tap all the time at a moment s notice. High water velocities combined with hot water can cause velocity erosion issues for the pipe and valve walls. The pumps are normally small factional horsepower constant speed pumps.

Calculate the gpm required using a 10 f δt or other value as determined by the engineer. Part 1 find the pump gpm determine the heat loss of the total supply pipe using tables or rules of thumb. Domestic hot water recirculation steps. The traditional domestic water recirculation system goes back in time a long way.

From there a small return is piped to the water heater. A return circulation pipe is sometimes provided in a hot water system where it is desirable to have hot water available continuously at the fixtures. Near the water heater area a recirculating pump pulls the water from the furthest fixture back into the water heater creating a loop. Time for hot water to reach fixture without circulation pump.

1 us gpm 0 0630 liter sec. Hot water return piping is closely regulated and strict adherence to the current building code is an absolute must when designing and ultimately building your project.