Every heating guy loves a vapor system.

Tony Viz

But what if the house is chopped up into apartments and a hydronic system makes more sense.

The Job......

Single family residence that was converted into six apartments.

Original Veco system. Half of it has the right orifice valves at the top of the radiators. all of it still has the little p traps on the returns.

The boiler is history in more ways than one.

The $64,000 Question

Would it be possible to plug in a couple of condensing boilers using the 4" main supply and the 1-1/2 dry return?

I would use a thermostatic Danfoss valves on the supply of every radiator and have to work in a air vent somehow. The little p traps would have to go. Pumping would be handled by some kind of smart pump.

All the return piping leaving the radiators is 1/2" so that limits BTU to 15,000 per radiator.

Supply piping to each radiator is 3/4" so maybe i could eek out 20,000

Not sure what my 1-1/2' dry return will handle as far as BTU.

Am I nuts to attempt this?

Steamhead

"Am I nuts to attempt this?"

Short answer is yes. The pipe sizes are iffy at best and the increased operating pressure will make something leak. Fix the VECO and put in a wet-base, power-burner boiler, with lo-hi-lo firing if available in that boiler size.



You can use TRVs on a VECO. Tunstall may even have upgrade kits to turn the original valves into TRVs. Vent the heck out of it and put in a Tekmar or Heat-Timer control to cycle the boiler. Then watch how well it works.