why purge heat exchangers?
Have you ever have gas? it makes you uncomfortable and not work so well same for heat exchangers
purge the build up of chemicals and residue that coat the tubes as they stop heat transfer from coils to water
Purging is very important so as to remove air so that there is a proper exchange of heat between the mediums without the air acting as a barrier....the air present in the heat exchangers will disrupt the conduction and decrease the efficiency of a heat exchanger and thus it is necessary to purge a heat exchanger.
In many heat-exchange systems, solids will fall out of solution due to the change in temperature. The solids can adhere to the piping walls and inside valves (etc.) and, in doing so, can dramatically change the flow-rates of fluid through the exchanger. Overall, this usually manifests as either a non-working or highly inefficient system. We used to call the cleaning (or purging) of the piping de-scale - because the junk that built up inside would come out as little flakes that looked like fish scales.
