I am trying to figure out what kind of material would be best used in order to transport water through a material that would be the same size/shape/diameter of a conventional pipe inside a home running water. The idea is that the water running through the pipe would be at a temperature of about 50 degrees Celsius. For example, if water was running through a copper tube or pipe, would the copper also be at a temperature of 50 degrees Celsius? Water will be coming from a source and will be in a constant flow from the source at anywhere from 50 to 65 degrees Celsius. The Desired material would carry the water from the source and then run towards a series of townhouses where the piping would run through the homes to provide a source of heat for the homes. The piping would then circulate back from the homes to the source where the temperatures inside the source would be at 50 to 65 degrees Celsius. Let's say the source is 100 meters away from the homes, and the tubing would be running 100 meters before coming into contact with the desired destination. The desired destination would then ideally have the water running through the tubes after traveling from the source at 55 degrees and upon arrival would be at a temperature of around 20 degrees. The tubes would be run underground before getting to the destination and the temperature underground is about 5 degrees Celsius. the desired material would be long lasting like concrete is and durable under temperatures ranging from -10 Celsius to 70 Celsius. What kind of insulation would you recommend to keep the material from losing heat when running through the homes? I also would sincerely appreciate any insight as to how I could go about figuring this out myself. My Goal is to have this concept being simple enough to convey it to anybody from a teenager to adult to understand. I am not a teacher or professor, and I am not asking this for a homework assignment, I am asking this question so that I can prepare myself for the best possible approach to utilizing a material to conduct thermal heat from water in a way to heat homes. Thank you kindly for your time and attention!