Typical CHW heat gain in distribution loop

[CelsoIII]

Is there a typical efficiency or heat gain rate due chilled water distribution and insulation inefficiencies?

Example: A Chiller producing 1000 tons/hr of which 750 tons are used by fan coil units and maybe the rest is lost in distribution heat gain. In this example the efficiency would be 750/1000 = .75 = 75%

 

[walz]

If your pipework is insulated properly, chilled water temperature rise will be fractions of 1 deg F.

I once calculated this temperature rise in a chilled water distribution network of more than 3.5 km (3500 m) of pipe length and amazingly that rise of water temperature at the other end was only 0.06 deg F. which is negligible for sure.

 

[Drazen]

I don't recall any recommended heat gain to be used for calculating insulation size for CHW pipings (as opposed to warm water), mostly because of the fact that condensation prevention will be issue of more priority in majority of cases, and that will be the factor which imposes insulation thickness.

 

[marcoh]

I did a detailed calc on a system a while ago and the heat loss on a 4000kW system was in the order of 50kW

 

[lurch17]

I have measured a couple of high-rise condo chilled water systems with typical fiberglass or composite insulation and found negligible loss, less than 1/2 Deg F from the chiller outlet to the end of the supply riser 400 feet above.

Usually, if you have significant parasitic losses through the insulation, they will be apparent - condensation dripping all over the place.