Medium size coop heating system advice
I think I should address this directly to Master Plvmber, but I would love to hear anything any other steam heat experts might advise. I am on a board of a medium sized coop which consists of 3 attached buildings 16 apartments each. The buildings are from 1914 or older. The 3 buildings are heated…
I think I should address this directly to Master Plvmber, but I would love to hear anything any other steam heat experts might advise.
I am on a board of a medium sized coop which consists of 3 attached buildings 16 apartments each. The buildings are from 1914 or older.
The 3 buildings are heated by a single Steam boiler through a one pipe steam system.
The boiler is about the size of a steam locomotive. The burner has been updated to a modern burner and as of 2 weeks ago controlled by a brand new MPC Platinum HeatTimer controller. I am a fairly technical person myself and heave taken it upon myself to figure out what is needed to make this system into an efficient one.
1. My first priority was to have the old mechanical HeatTimer controller replaced with an electronic one , so that we could really see and control what is going on. When the controller got replaced, the person (who is a knowledgeable plumber) installed the system temperature sensor on the condensate return pipe in a room near the boiler. I believe that to be incorrect, and that it is supposed to be installed at one of the return pipes on one of the far ends of the system. That way “Heat established” state can be accurately determined.
2. The building directly above the boiler always ends up being overheated. We have replaced all TSV valves in the building at the start of the last heating season but that apparently isn’t enough as the boiler keeps enough fresh steam in the risers to overheat the building. At the same time the far ends of the system are usually getting just enough heat to be comfortable. As far as I understand that is because the heat balance is set high to make the burn cycle long enough for the steam to get to the far ends of the system. My question is , can a one pipe system like this be split up into zones? I know HeatTimer sells Motorized Thermostatic valves. Could those be used to shut off the steam from the building that is above the boiler to pass the steam pressure over to the other buildings ?
Yes MP is exactly right. The sensor is measuring the temperature on the return pipe.When an adjustable temperature is reached, HeatTimer considers all radiators in the building to be hot AKA “Heat established”. From that point HeatTimer starts counting down the minutes to boiler shutdown based on the letter designated heat-balance setting (also configurable).
I’m in Windsor Terrace (Near Bartel Pritchard Square that’s a circle 🙂 )
It’s not a valve, it’s a sensor and when its setting is reached, it tells the Heat Timer to start counting down the minutes until the off portion of the cycle.
MP and Bruce:
I am trying to clarify what the valve on the return line actually does. Does it just tell the timer when all of the radiators are full of steam and shut down the boiler?
My take on this situation is different. I work for HVAC companies and I have seen too much money spent chasing efficiencies that aren’t there.
Steam zone controls are expensive. That would be a last resort. Assuming that competent air elimination balancing has been implemented and is inadequate to resolve the imbalances, I go back to your description of the existing boiler. which sounds older.
New boilers are a little pricey, but separate units might be physically smaller than existing, and from the ground up are more efficient, and more importantly, controllable than one source being apportioned. The Board may have a short attention span, but assuming fuel prices will return to expensive, the ROI may be far shorter than you think.
I’m not positive what Heat Timer calls it as I am more familiar with Tekmar’s terminology.
But “steam established” is the setting associated with that return sensor.
MP:
The system sensor on the return line is to tell the boiler when all of the radiators are filled with steam, and this is called “heat established?”
Gosha:
Where are you located?
Well, they’re called Thermostatic Radiator Valves and are abbreviated as TRVs.
I’ve never seen it any other way.
What are the TRVs? Is that a typo or just a different way of calling the same thing? I was referring to Thermo-Static valves at each radiator.
And with regards to risers, they are not one per building, there are 4 apartments per floor , with 3 risers per apartment. I will try to check if they converge somewhere.
The system sensor should go on the farthest return pipe just above the water line. The steam established setting should be set by measuring the temperature of the pipe at that sensor’s location when the last radiator has been filled with steam.
You should seriously consider installing one or two room temperature sensors to the heated spaces to give the Heat Timer some indoor input. That makes a night-and-day difference in how the cycle length is established.
If there is one riser to each building, considering a zoning device might not be a bad idea if the TRVs aren’t working out for you.
They should, though. I’ll bet they work much better once you get a proper cycle time established.
Good luck,
Me:
http://www.GatewayPlumbing.com