How short can a primary loop be?

Bob Vennerbeck

I'm trying to work out a good piping layout for a Triangle Tube Prestige Solo 110 - it will have three zones of fin-tube baseboard, and eventually an indirect DHW tank. This is my first time designing a primary/secondary system from scratch. Is there a minimum length or volume that the primary loop should be, or can the 'closely spaced tees' be pretty much right off the boiler tappings? (they're actually nipples protruding from the bottom face...) - I would obviously run the primary far enough to include whatever unions and/or isolation valves seem appropriate, but is there a benefit to running the primary 5-10 feet out and back? In the same line of thinking - all the Primary/Secondary piping schematics I've seen (both in the TT manual, and 'in the wild') show a pair of tees nicely aligned, with boiler on the runs, and system on the branches, or vice versa. Does the geometry and alignment matter, or is it simply a matter of having the primary and secondary loops share a short section of piping?

I don't want to make this so neat, tidy and compact that it doesn't work...



Thanks for any advice



Vbob

CMadatMe

Use a Hydro Sperator/ Low Loss Header

Scrap the primary secondary and use a LLH. This will help in a few ways. No water temp differences across the zones as zone open at the same time and will help the boiler to promote condensing.