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Typical steam pressure at the convector for a University dorm

spaz
spaz Member Posts: 3
edited November 18 in Strictly Steam
Morning folks. New here.

I have a 17 years of experience with residential HVAC and then 20 years experience at a commercial chiller plant for the U Of I.  But the university auctioned my job away and now I’m a maintenance man at one of their student dorms with about 100 residents. The original building was built in 1912 and then added four additions throughout the years. We are supplying 15 pounds of steam pressure to our convectors and I have been told that’s excessive. Is this true?  

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,272
    edited November 18
    YES

    You need to provide more information, can you access the boiler room?
    The Empire State Building is feeding steam from the basement to the top with about 2 PSI steam pressure
    (Why do you ask Two Dogs?)
    Are you experiencing any problems with not enough heat in some areas and too much heat in others?
    Edward Young
    Retired HVAC Contractor from So. Jersey.
    Services first oil burner at age 16
    P/T trainer for EH-CC.org

  • spaz
    spaz Member Posts: 3
    We get steam from the boiler plant and it’s actually more like 12 pounds.  We also have different processes in the building such as flow rite water heaters and heating coils in the air handlers all using the same steam pressure.   What we’re experiencing is the tenants use the convector steam valves as on off switches. When they get cold they crack it, when they’re warm, they close it.  My opinion the valve should never need to be shut and you should be able to adjust how much heat is in the room with how far the convector valve is open.    
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,654
    @spaz

    The issue is the convectors are one thing. You have a lot of equipment and have no way of knowing what steam pressure the equipment is designed for. You have 2 choices.

    1. Find some documentation, drawings, equipment submittals or the original engineer who could tell you

    or

    2. Lower the pressure until someone complains. Typical for those types of buildings is 5-10 psi.

    Commercial steam is different from residential or a straight heating system.
    spaz
  • mattmia2
    mattmia2 Member Posts: 6,655
    spaz said:

    When they get cold they crack it, when they’re warm, they close it.  My opinion the valve should never need to be shut and you should be able to adjust how much heat is in the room with how far the convector valve is open.    

    That may be a battle you'll never win unless you can limit the max steam available with the valve all the way open to about the heat loss of the room and then maybe a little for recovery without them knowing you did. In residential systems stops that keep the valve from opening more than a certain amount work but kids in dorms will defeat that. They might even defeat valves with a separate metering valve in them. Either a valve before it enters the room or an orifice plate in the connection has a much higher chance of success. Of course that needs to be calibrated for your supply pressure.

    spaz
  • pecmsg
    pecmsg Member Posts: 3,335
    edited November 19
    Download and read:
    https://www.av8rdas.com/honeywell-gray-manual.html

    Are the original design prints available?
    Commerical has so many ways of achieving their goals. I've seen HW with manual outdoor reset for convectors.
  • spaz
    spaz Member Posts: 3
    edited November 24
    Thanks everyone.
    I'm not aware of any documentation. I'm sure it exists, but the message I'm getting from management is "this is the way its always been". My leads response when I told him the empire state building feeds steam from bottom to top with 2 PSI was "yeah I watched that fake video" :|
    A energy audit would be in order, but I'll try and convince my supervisor to adjust the steam pressure down slowly until we see problems. I had that ability when I operated the U of I chiller plant years ago, but not any more.
    Are there any links that are short and sweet that might help convince management other than this discussion?
    Thanks again.

    Edit: Flo-rite water heaters operate on 2-15 psi, and guessing the coils in air handlers do as well.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,654
    Higher steam pressure can make control valves hunt. I would just lower the pressure 2 lbs at a time until you get complaints. If you had a way to put a pressure gauge at the far end of the most heavily loaded main that would help.

    Lower pressure saves ware & tear on traps and control valves. Not that there are not systems designed for high pressure their are but it's a waste of fuel to run higher pressure than you need
    spazbburd
  • The Steam Whisperer
    The Steam Whisperer Member Posts: 1,035

    Higher steam pressure can make control valves hunt. I would just lower the pressure 2 lbs at a time until you get complaints. If you had a way to put a pressure gauge at the far end of the most heavily loaded main that would help.

    Lower pressure saves ware & tear on traps and control valves. Not that there are not systems designed for high pressure their are but it's a waste of fuel to run higher pressure than you need

    I'd pick this way to address the issue. It's one way to get around "we've always done it this way". I used that same process for a building up in LaCrosse, WI. Lots of banging. I gradually turned down the pressure on the building and the banging gradually disappeared until I got down to 2 psi. With those higher pressures, you get lots of flash steam banging in the returns.
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • retiredguy
    retiredguy Member Posts: 658
    Here is what I saw when trying to solve problems at any building complex that had numerous additions, many years apart. Each design engineer had his own way of sizing equipment, sometimes based on the amount of money available for that addition. They would also specify the steam pressure required for that addition with no regard for the existing buildings requirements. The building was built and the heating system commissioned. Now, the problems begin.

    The way the job should have been laid out is that the design engineer would use the specs for the original building and use those specs for his new building. If he wanted a lower design steam pressure for whatever his reason he could always add a "steam reducing station" for that addition. If you chose to challenge that engineer for his stupid mistake you had to choose your words very carefully since he was the "chosen one". I sometimes forgot that fact and it wasn't pretty.
    pecmsg
  • BobC
    BobC Member Posts: 5,350
    I learned discretion was a valuable tool when I was in the army over 50 years ago. A SP5 can tell the major he's wrong but you have to do with discretion. A good officer will begrudgingly accept it, one that is bullheaded or vindictive just has to be left to founder on his own - just make sure you get yourself out of the line of fire first. Sometimes the only thing you can do is follow their orders exactly and hope they see the light before the damn thing blows up.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,654
    @retiredguy

    I have not seen an engineer who was wrong and admitted it very often.

    I had a steam job once where the customer hired an engineer (who knew nothing about steam) to design it. The engineer knowing, he was over his head called the local Sarco rep to help him, but the Sarco rep was never given the opportunity of looking at the job.


    The boss bought all the parts they told him to by (he didn't know steam either. So I get the job to install this. A big steam humidification system with flash tanks, traps, reducing stations you name it.

    Long and short they didn't need half the stuff they bought.

    I complained to my boss and he called the "engineer" who met me at the job with my two pages of notes on what was wrong.

    Every question I asked him he said "I will have to review that"

    I finally got the Sarco rep there nice guy and very experienced. I told him I didn't think we needed all that stuff and he agreed and everything worked fine