Harold, the reason I like a slower velocity (Hazen-Williams) It does prevent eroding and other adverse conditions BUT as we know slowing the heated medium too much could cause another problem associated with a wide spread “DELTA” from supply and return water (thermo shock)
The ideal Delta I feel should be no more then 20 degrees But thats my opinion
Plumbers may know how to size the piping for domestic/potable water supply hot and cold But I find most journeymen are lacking in heating piping design and applications.
I also find that few “plumbers” get involved in fire suppression systems as the “K” factors and single sized piping arrangement systems tend to bore them as the sprinkler piping today is like putting a tinker toy set together with everything marked.
Plumbers are a natural for installing the smaller fire suppression systems in one family homes but they seem never to follow up on this built in gold mine.
I think the biggest turn off today for most legitimate plumbing contractors is the heating field is all the non licensed folks dabbling in under slab systems and the unknowing going to home centers for advice.
Dan H, wrote an article about going to a home center many years ago where this clerk said “one boiler fits all in residential applications”
When mentioning a Hoffman 75 with an Apollo ball valve below it for servicing the home center mentality kicks in asking CAN IT BE DONE CHEAPER never asking is this the right job?
I still install Cast Iron base board heating and Burham cast Iron radiators and NEVER have I ever installed a loop system always a two pipe system on hydronics
Very few apprentices learn EDR for steam (1 Sq. Ft will put out 240 BTUH when there is a 70 deg. Ambient around the radiator and 215 deg. (less then 1 psig) inside the radiator. Or 1 Sq. ft of EDR will put out 150 Btuh with an average temperature of 170 deg.
Ask any apprentice to go from EDR to BHP? Or EDR to Grate area in Sq. ft or EDR to BTUH steam at 1 psig.
Today they figure fixture units or developed length BUT have no clue that the figures they are using are no longer applicable.
The shame is ANYONE can and does advertise “heating” with no skills required.
At least if the plumber has a license you know he/she is insured.
Harold as always your a real pleaseure to talk with. please keep the education going as Lord knows the apprentices need your training as they cant seem to learn it on their own any more as the dead men cant tell them why!!! LOL