Insulated potable hot water line in ground - Loss of heat?

[headrc]

In my boiler design I am thinking of having one potable hot water source for two buildings ...which will require having the supply of potable hot water for one building run in the ground for 75-100 feet through insulated pipe ....which by the way will be right next to the hot water line for the water heat exchanger in that building( 3 lines in insulated pipe). My feeling is since that line will always be carrying hot water in the winter months ....will it not help the potable hot water line retain its heat so we will not have to flush the line everytime potable hot water is demanded? Does anyone have experience with this type of installation ....or suggestions to make sure that there is potable hot water available on demand at this building? One thought I had was to keep the hot water circulating with a pump ....but I would like to avoid this if possible. Thx, RH

 

[Willman]

There are circulator pumps that can be controlled by motion or timer or manually switched.They don't have to run constant. You would need another pipe or tube to return the cooler water. When temp is reached faucet is ready with hot. Bundling with heat supply and return in same trench is a good idea. I don't think they should touch though. Although DHW running shouldn't pull too many btu's from heating requirements. Remember heat always seeks out cold.
Will