Dear All, how to size hot water
Dear All, how to size hot water
(OP)
Dear All,
how to size hot water return pipe ? the common sizing method is to determine the heat loss from supply and return piping, but i don't know how to determine the heat loss for PPR and CPVC pipes?
how to size hot water return pipe ? the common sizing method is to determine the heat loss from supply and return piping, but i don't know how to determine the heat loss for PPR and CPVC pipes?





RE: Dear All, how to size hot water
Determine the heat loss per foot of pipe with(out) insulation and determine the flow rate that will enable you to provide enough flow to counteract this. Size the pipe for that flow rate.
RE: Dear All, how to size hot water
RE: Dear All, how to size hot water
I never depend on tables without understanding what they represent.
As an exercise, you should use the thermal conductivity of the pipe material in question in the heat transfer equation to get real numbers. Then compare to the tabulated values.
If you are insulating the plastic pipe, the total heat loss will be comparable to that of insulated copper since the insulation provides enough resistance to heat flow that the difference in conductivity of the pipe material is insignificant.
If you are not insulating the pipe, then the difference in material will play out.
Since copper tubing and the plastic pipe material have essentially the same roughness (epsilon), there is not significant difference in the friction loss - but you do have to consider the difference in pipe inner diameter.
RE: Dear All, how to size hot water
RE: Dear All, how to size hot water
http://insulationinstitute.org/wp-content/uploads/...
RE: Dear All, how to size hot water
https://go.bluevolt.com/Grundfos/CoBrandTemplate/C...
RE: Dear All, how to size hot water
You can use 3Eplus to calculate the heat loss per linear ft for different pipe and insulation configurations. Its free.