Why are cast iron emmiters and diverter tees no longer used?

Yup- build them as cheap as you can, get as much money as you can, and don't answer the phone when people call to complain. That's how builders and remodeling contractors work. It also explains why Codes had to require things like insulation and better windows before builders would use them.

If you want to be completely disgusted, watch a Ryland home being built. It's amazing these things don't fall apart in two weeks.

Installing Cast iron BB is slow work and it's heavy to lug around (2 man job)... and you need the joiner tool to combine sections... and sometimes they leak. It's also 4x the price of fin-tube... so that and the increased labor time to flush/assemble/add fittings/pressure test/install the cast iron vs fin-tube makes fin-tube the low cost winner.

That being said, most here know the tremendous advantages cast iron BB offers over fin-tube. When used with a mod-con CI BB can prevent short cycling, and even regular cycling plus negate the need for a buffer tanks on smaller systems.

If you can do the work yourself, all sorts of options. Occasionally you find free radiators, yours for the hauling.

I've found them very easy to get heat out of, just get HW in and out some how. Even single pipe steam rads will work on hydronic systems.

I drove to Omaha one day and back, 8 hours for a unique corner rad that someone here turned me on to. It was scrap yard bound! Got it at the front steps of a 125 year old home being converted to FA.

Most home owners care more about having A/C in their new homes than the heating.
In my opinion that is why air heating and A/C systems are so popular.
Most home owners will not pay extra for a Hydronic heating system and a separate ducted A/C system.
In new construction you could have an A/C system with Hydronic duct coils and an boiler that will do the heating and if you want certain rooms to be heated by radiant or cast iron / copper baseboard or even aluminum panel radiators.
But with most new construction homes the builder gives a certain dollar amount for the heating and A/C systems and to get Hydronic heating system that would be and extra cost to the person buying the home.

I agree the monoflow system, is of the best..never a problem with a properly installed one...Its when happy hands the handyman puts his paws on it, it gets interesting to say the least....How many simple kick space heaters do you come across that don’t work...I saw lots of them...And yes I definitely agree that the builders and general contractors are the worst...they charge customer top dollar and then search out the dumbest cheapest hacks they can find...Not many shops around here partake in the circus , to many learned the hard way, like me...

SuperTech said:

I think a good HVAC installer or plumber could install a nice two pipe diverter tee system with TRVs for a competitive price. The TRVs would offer better temperature control than zone valves. If homeowners were more informed on the benefits of the higher mass systems cast iron could make a comeback.

Trouble is we Americans sent most of it to China...then we buy it back at an enormous upcharge...I had used some new locally manufactured c/I rads, piss poor workmanship...Cast iron is great, but not to most Jmo

A Monoflow system was installed in our bank. The piping hung low below the basement floor joists. 30 years ago they wanted to finish that space and it was my job to raise the piping. Had little idea what I was doing. Could solder pipe and didn't know much else. Raised all the piping up nearly tight to the ceiling, rerouted for best finished ceiling. There were 2 to 3 sets of tees that had been capped from a previous remodel. Never knew that could have been a problem. Air removal was not a problem....didn't know there should have been.
Each convector had an air bleeder on a long pigtail.
The system air venting consisted of an 1/8" air vent tapped into the top of a tee....nothing else. Had a compression tank. No problem with start up.
20 years ago took the entire system out, as major addition was getting the entire building converted to roof top Heat Pumps!.
The copper went into my basement heating system and is still there. 1 1/2" return with 1 1/4" loop around the bank basement.
I will be using the remains of the 1 1/4" for some boiler drains.
The monoflow tees were 1 1/4 x 3/4.....I still have them on my shelves......why??

L Thiesen said:

...Just make it look good...

In addition to installing cheap, scorched-air junk heating, they don't even make the houses look good. Recent 'designer' lipstick trends have become uglier and uglier.

The worst of all possible worlds. Functional and aesthetic dreck.

The desire to have AC also drives potential heating system choices.

Even in the high mountain regions they are now often seeing weeks of above 90F temperatures. That was one of the last markets willing to accept hydronic heating only systems.

For resale consideration also, virtually all homes and commercial buildings look at AC and FA or VRF options.
It's a tougher sell for hydronics when a second FA system needs to be included.
In some cases mini splits can be an option for cooling or shoulder season heat loads.

Yeah, I think many of us share that love of the older technologies and equipment.
Most, but not all consumers are more into low cost throw, away stuff, including their comfort systems. Probably not even aware of what true comfort is, maybe never experienced it.
Or care to

Monoflow or venture was not invented until the 1950s

House I grew up in was built in 1922, but was retrofitted from scorched air to hydronic at some point. Based on a 36"x36" filled in hole by the chimney, asumed to be a gravity air return. But there is little ecidence of any other floor penitrations or ductwork. Large Arts&Crafts home.

All threaded pipe so I assumed it was prior to 1950 as it seems copper would have been used. B&G brand Mon-O-Flo one on each return, two zones one per floor. Had 3 piece B&G circulators when I was a kid, had to oil them every month or so or else they let you know they needed it! Line voltage Honeywell mercury vial thermostats.

That was a "pipeless furnace" where that 3-foot square register was all it had. Hot air would rise and cold air would drop thru the same grille. The Monoflo system was a major upgrade.

Many houses in the Baltimore got similar upgrades- many steam as well as hot-water.

Never knew how good I had it, 60 year 1 ft high old cast iron baseboards and mono-flow fittings. 1 zone, Very uniform heat.

I'll have to post questions after I take some measurements and make a picture of the layput.