Microbore-style Systems in the US?

NTL1991

Hey guys. Came across some pictures of microbore systems over in Europe and I’m impressed with the 8-12mm pipes they use to connect their panel rads. Anyone know of any systems like this here in the US? I’d be curious to know how the heck they can get sufficient BTUs through pipe that small. Also curious about what kinds of static pressure and pumps they’d be using.

Sure looks like it’d be easy to fish that pipe anywhere you needed it.

Big Ed_4

I always run 3/8" on my home run systems .but use "A" Pex ... 1/2" can deliver 28K why use if the radiator is much smaller .. The problem is finding 3/8" manifolds .. They disappeared .... Do you think 1/2" is easy to run , try 3/8"

In the early fifties spaghetti systems where installed , home run system using convectors . They even used tube type outdoor resets behind the kitchen clock ....

Over there they ask for the best , over here we ask how much ...

hot_rod

Euro based systems often run wide deltas, 30 to sometimes 40 delta 
The also do home run piping so you don’t take that series radiator piping temperature drops
So short, small diameter tube running high deltas

Caleffi offers 3/8 Pex fittings for manifolds, a nice universal fitting for all types and brands of Pex 
As well as the 5/16 diameter fitting.

Properly designed that 5/16 Uponor  or Viega could be used fo radiators if you want small readily available US (micro) Pex.

Here is the Viega pressure drop chart.
 Consider a 1 gpm flow in a 100' loop, of 5/16" pex, running a 30 delta, which would be 15,000BTU/ hr
500 (f) ∆T
500 X 1X 30∆= 15,000
100' loop X.002/ft. = 2 psi pressure drop

hot_rod

Caleffi Pex fittings for manifolds, TRVs etc.