Hi All,
First post and i can't get the search function to work. Sorry if my question is addressed already.

I have read John Siegenthaler's book "modern hydronic heating". I am working out some designs for my house and have a problem with flow velocity. I have a situation where i have 6 circuits of about 200' in length each, this constitutes a zone. When resolving this setup in parallel, the flow rate required in each circuit is low (.4 gpm). This gives flow velocities of about .65 ft/s. This is far away from 2-4 ft/s recommended to keep air in suspension. I understand that the common piping will flow faster and therefore remove air where the actual separator is located, but will the individual circuits be a problem?

AMAC

no. the 2-4 ft/s recommendation is really pretty silly. in radiant loops this recommendation is routinely ignored.

Many thanks!

High velocities are noisy, pump hp is greater, and the possibilities of piping erosion are real. 8 feet per second is the maximum velocity pex tubing should be subjected to.