one-pipe steam heating delays

hollyhouse

Hi,

I live in a NYC coop that has 84 units, 6 floors, end-to-end is about 200' from boiler to the other end. I see the boiler cut-out is set to about 4 psi (by observing the gauge), and the super explains that when the contractor setup the new boiler two years ago, they tested it and say it needs to be higher or else some apartment would be cold. I am trying to see if I can do something to improve the unevenness or the excessive heating bills. I put a LoRa temperature sensor on the 8" main exiting the boiler, and another in my apartment on the first floor that's at the far corner, and I see about 10 minutes delay of heat reaching my radiator from the first cycle in the morning, and thereafter it would take 4-5 minutes after the pipes are warmed up. I am guessing this is not normal. I see sections of the 8" & 5" main not insulated, so that's what I would start with, by insulating those. I am guessing master-venting may be needed also, but I am not sure we have the budget for that. What would the typical cost for a master-venting project cost?

also, I was reading the operating instruction that comes with the timer-controller, and it says the system temperature sensor should be installed at the far end of the dry-return. Ours is installed right in the boiler room, at the wet return near the timer-controller. Would this cause the timer-controller to stay on longer than necessary?

thanks for any pointers.

Tony

mattmia2

i don't think your time to heat is abnormal. if it really does need 4psig to heat you have failed closed vents, if the air can't get out you can get some poor heat by compressing the air that can't get out. so it sounds like radiator and main vents and vents on the risers is the first place to look.

bburd

If the Empire State Building can be heated with 2 pounds of steam pressure, most likely your building can be also. Something is wrong. Most steam heating systems work best on 1.5 pounds or less.

hollyhouse

One other challenge we have is access to individual apartments' radiators. Super says he can only rely on people telling him something failed. There is no way to get access to some apartments unless there is an emergency. Some shareholders even prefer to hear the hissing of the steam vent to feel comfortable that the heat is working. From reading the post on this site, I understand we shouldn't need 4 psi, and higher pressure travel slower also. But what do people do when access to 84 apartments are not feasible and we have to figure out which vent failed? Should I start with the one complaining of low heat, and look below that line to see possible failure? The only riser vents I see are the two in staircase/bulkheads. I measured about 3 minutes delay from my radiator on the first floor to the bulkhead air vent. Beside those two, are there riser vents in the 6th floor apartments for each riser?

Also, what would be the price range of getting someone to vent our mains/risers properly, for a building our size?

thanks

STEAM DOCTOR

We would really need a lot more information. It is a one pipe or a two pipe system? Can you take some pictures of the boiler and the boiler piping and the end of main venting. And some random radiators, with the radiator piping. You would really benefit from having a pro on site.

STEAM DOCTOR

And price discussions are absolutely not allowed on this forum.

STEAM DOCTOR

And just remember, you are not spending money, you are investing money.

bburd

Depending on the design, some steam air vents can be damaged at pressures over three psi.

Mad Dog_2

Hi Tony. That can certainly be improved upon. Mad Dog

Long Beach Ed

The location of the "steam established" sensor must be at the end of the main. Otherwise apartments at that end will always be cold.

Steamhead

@hollyhouse , you really need a steam pro to look at this. Fortunately, there are plenty in NYC and surrounding areas. One of the best, @Mad Dog_2 , has already posted in this thread.

Improving response of a steam system- or any system- can lead to significant fuel savings. My company has a couple steam-heated buildings where we've cut consumption by a third, though these are extreme cases. But the fuel savings often pays for the work, and frees up money later on to do other things.

Mad Dog_2

Here to Help! Thanks Steamhead! Mad Dog

mattmia2

If the sensor is really below the water line it will not sense what it is supposed to but it may be ok at the end of a main returning to the boiler as long as it is before the vent.