(not verified)
Posted in: , on 7. Jun. 2001 - 12:07


can somebody tell me from what temperature on a filter or a duct work has to be thermically isolated to prevent condensation?

Calculating the dewpoint or the relative humidity does not cause any problem, but how far away do we have to be from these?

Working temperatures are around 80°C.



Posted on 30. Aug. 2001 - 10:31

Dear Reinhard,

If the temperature outside the pipe/duct is well above the maximum possible dew point there is no need of insulation to prevent condensation outside the pipe / duct. Please note that dew point vary depending on relative humidity. If the criteria is only to prevent condensation providing sufficient insulation to keep surface temperature within about 5 degree above dew point should suffice.

In most cases prevention of condensation is not the sole criteria for providing an insulation. The other criteria being

  • Reduce wastage of energy in heating / cooling
  • Control surface temp for personnel and equipment protection.
  • Control the temp. of commercial and industrial processes

etc to name a few

You may visit http://www.insulation.org/pages/Pfaq.html where some frequnetly asked questions are answered

Good Luck