Will TRV's Help?

trivetman

I've got a two pipe steam system in a large 3 story house (4500 sq ft). The thermostat is on the main floor, and recently the top two floors are generally 5-7 degrees warmer than the main floor. I'm wondering if TRV's are a good solution?

When I first owned the house the top floor radiators got no heat and it was too cold up there. The system has no steam traps and it turned out the steam was passing through the first floor rads into the returns and screwing up the venting. Gradually all radiator valves to the point where steam didn't hit the returns solved this problem. I could take this same approach by partially closing the top floor valves, but am wondering if the TRV's will give a more consistent temp.

Any reasons they might be a bad idea?

Some of the radiators have metal box covers. Are there TRV's where the sensor is separate from the valve and can be put somewhere outside the cover?

I've also considered putting in orifice plates to help limit the steam passing through to the returns. Can these be installed along with the TRV's?

EBEBRATT-Ed

Yes, putting trvs on the second floor will balance things out and prevent overheating. They do make valves with a remote sensor for both 2 pipe and 1 pipe steam

Is this one pipe steam or 2 pipe? Steam traps or no steam traps?

trivetman

2 pipe. No traps. From what I understand the system likely was designed for orifice plates but I suspect they are no longer in place.

It runs at around 8 oz pressure with a vaporstat

trivetman

Any specific TRV's recommended? I haven't seen those with remote sensors though I just started looking.

EBEBRATT-Ed

Macon Controls sold by Tunstall Corp. They hang out her sometimes

Honeywell makes them and also Danfoss makes them

gfrbrookline

The honeywell's don't have vacuum breakers which made the pipes bang in my system. Swapped them out with Danfoss and quieted everything down.

clammy

Is this system all wall convectors ,I have run into these types of systems and like you no valves just standard unions on the convectors . Most I have ran into where vacuume systems originally most switched out to air vent systems which as I have seen usually lead to some balancing issues and uneven heat being they where not designed to be air vent systems and from what I have noticed they do not distribute steam as quickly and as even as when they where vacuume system ,just my take . Are you sure the boiler was properly sized for the radiators edr ,if undersized that may be your under lying issues . Are your main vents working properly. Does your system have any cross over traps ? And are your end of the main drips dripped into a wet return and do they have vents on them and if so what type of vents ,ex gorton ,Hoffmann . Usually I ll closely observe the system cycle before making any changes like up grading venting changing to a air vent system or returning to vacuume .most convert to air systems but from my observations there s usually some distribution issues as the distrubition is not as fast . On a side note all boilers need to be piped properly and 2 pipe vacuum systems are no exception mis piped boiler produce wet steam which will always leave to issues down the road including poor distribution and and performance .are your steam mains insulated and has anyone ever checked your system out to be sure it piped correctly aside from those who installed it usually when piped wrong the original installer will always say it’s correct cause they are not repiping .And has this always been a issue or something new ? Peace and good luck clammy

trivetman

> @gfrbrookline said:
> The honeywell's don't have vacuum breakers which made the pipes bang in my system. Swapped them out with Danfoss and quieted everything down.

The vacuum breakers are for one pipe right? Mine is two pipe.

trivetman

@ clammy

The rest of the system has its issues. The boiler is probably too large. Fills up the rads at about 35 minutes and starts short cycling on pressure. Near boiler piping is not right and draws a lot of water/wet steam up into the pipes. Ive only owned the house 3 years - the boiler is probably 35 years old and I am hoping it gives me another few years before I have to take on the expense of replacement and repiping

All Radiators do have valves and mains are well insulated - just did that project with 1.5 inch fiberglass. Also mains and dry returns are well vented