Zoning a one pipe system in a church

Christian Egli_2

Propose to the church that the system should be first thoroughly maintained and that all venting should be optimized (as in returned to original working conditions). Why? Because this always leads to energy savings, sometimes lots and lots of savings, and it also leads to a system that heats the building most wonderfully.

Poor maintenance and disrepair is perhaps all that prompted this congregation into looking for a way to reduce fuel bills. Meanwhile, they forgot to look at repairing what they have and went on a wild goose chasing scheme.

Fix first, then if everything works with wilder than expected economy, you're done. Only once everything works nice, then propose some overheating saving cures such as thermostatic valves and optimized boiler control.

If you can fix the system, you're the real champion and the church will be the big winner. Don't back out too quick, Bryant.

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Incidentally, optimized boiler control by such people as Tekmar and HeatTimer modulate boiler cycling to match heat output to heat needs as determined by outdoor sensors and such. -freak, this again follows your intuition and delivers chopped up heat, just not volume trimmed by playing with radiator venting, but parceled out along a cut up time line that cycles the fire on and off.

The ultimate reset in steam is the Varivac and the Dunham differential system, and along those complicated lines, the simple use of vacuum vents will give you the lowered heat at the radiator for as long as you keep a lower fire at the boiler. All of this is doable, of course, dealing with vacuum is a fun game, but it rarely plays fair. Just installing vacuum vents does not do the trick.

Nothing really new as far as fancy ideas, they're done all the time in process applications, but for home heating the tried and tested simple methods have a lot of merit and economy all on their own.

Thanks for reading and enjoying your fix of steam without the scary bat-like flying skull tearing itself off the wall... Freaky.

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And to answer John's questions, yes, no, yes. Your thinkings are lined up in the right direction. Zoning, for the simple sake of dead ending portions of your building only works in a comprehensive scheme. You can't forget boiler modulation.

In this regard, steam and hot water and hot air systems are exactly similar, you can't go around closing most of the valves or grilles and expect wild savings. Choking off either the hot water or the steam output of a boiler causes it to operate very inefficiently. Steam modulates easily, so do hot water boilers. Closing off the register in a hot air system causes you all kinds of massive waste (hot air furnaces don't typically modulate at all).

You can't have heat for free. And be very leery of too good to be true promising gadgety schemes, the worse of which is always the conversion plan. Follow the money.

What's always really surprising is that people expect the same comfortable warmth at half the cost for the simple promise of a zone and/or thermostatic valve. They also expect the new valves to cure all the lack of maintenance accumulated over the years.

We can't promise the moon. But a nicely operating system, with everything in balance is the first thing to consider for comfort and economy, and radiant systems shine in this arena of steamy hot radiators.

Bryant_3

Zoning a one pipe system in a church

I am looking at a job that is a 100 plus year old church that has a one pipe steam system. There is a parish hall in the basement and a very large church . The system has one thermostat and heats everything at once. The two mains head to each side of the church heat both radiators for both floors all at once. Another contractor is proposing zone valves to cut off the radiators for the church when not used. I feel this is going to lead to large problems with condensate return and also banging. Is it possible to zone a large one pipe system and what is involved to do it correctly?

Unknown

This sounds like the same

job we are on now - one pipe steam heat in a church , 2 steam mains . What we come up with is thermostatic radiator valves for steam . I think they're made by Danfoss ? I'll know better tomorrow when we pick them up . They'll give you much better room by room control than steam zone valves , and alot less velocity issues if for instance one zone valve closes .

Bryant_3

Yes I thought about that but then someone would have to go around and adjust the radiators each time they need heat in that zone. Big church 5-6 radiator valves each time they have a service would need to be adjusted to zone the church seperate from the Parish hall. We want to just zone the parish hall and church seperate as in two zones

hvacfreak

wondering aloud

Do they make small steam rated valves that could go between the the rad and the rad air vent ? Pneumatic or electric , that could be closed for " unoccupied mode " ? Just thinking out loud I guess.

flange

steam zoning is done all the time. you need to think about where you install zone valves though. you will need a trap upstream of the zone valve to prevent the valve from getting ripped apart after long periods of closure. zone valves can be either electric or pneumatic depending on what is available.

Christian Egli_2

You won't find air in paradise, only clouds of steam. Zones?...

Wooa, think over all of this many times.

Zone valves on mains, like two zones for two mains on systems that work with air vents is an easy recipe for disaster. Zone valves at each the one pipe radiator inlet are very tricky too because their hole needs to be so extraordinarily big.

Saint Peter is doing his duty at the air vent, controlling the access of the atmosphere into the steam paradise, but now, because you think his job could be optimized, you decide to install a zone valve on the road to heaven... why not... God might have thought of that himself... but who do you think is in charge of this main zone valve? Spitting pipes, thunderous banging and raging boiler water line should clue you in... be very careful who you sell your soul to. We have free will.

In one pipe systems, don't try controlling the steam, it's heavenly, it knows what it's doing better than we can. Instead control the demonic air.

That's exactly what one pipe thermostatic valves do.

Those available at Tunstall have a nice servo-motor module that can be switched for the thermostatic capsule and ta-da you have an electrically controlled radiator. Tie a bunch of them to a switch (or thermostat, or whatever) and you have a zoned control. Easy and painless as far as piping goes. It's what hvacfreak alluded to. The valves Tunstall represents are nice because they use a thermal motor which is slow to operate. I'm sure other brands do too, I don't know off hand.

Lastly, you need to know exactly how the boiler is sized for the system and you need to make sure the steam appears within a set range of pressures, low and lower being the key. You also need to review the main venting.

Did this help or scare you? Where is your church located?

hvacfreak

thanks

[quote] Tie a bunch of them to a switch (or thermostat, or whatever) and you have a zoned control. Easy and painless as far as piping goes. It's what hvacfreak alluded to. [/quote]

I have dealt with Danfoss 1 pipe valves ( air vent control type ) and figured this was how it is supposed to be done. I was gussing there had to be a " motorized " device available but just didn't know what products were available. Well written post by the way.

Probrobly not an origional idea , but to take this to another level , how about a digital control that would modulate venting capacity ...say based on outside temperature / space temp change trends ( I am thinking about valves moving very slowly ). I'm not sure the ends would justify the means ( efficiency ) ..but from a comfort standpoint this would be ideal. -freak

Unknown

hvacfreak............

Do you mean like a slow venting "throttling" kind of device, to vent the air, that could be installed on an indoor/outdoor? There is a Co. that has them, but their name escapes me right-now.

hvacfreak

yeah

I was thinking more on the lines of using a universal control and " building " this , but there may be a package out there. 0-10 or 4-20 output to modulating air vent valves.

edit.. Tuning this would be interesting...I have one pipe steam in my house...if someone like Johnson or Seimans would provide the hardware , I'd give it a shot , LOL.

DanHolohan

For your consideration

Motorized Valves on Steam Systems

It pays to wander off the Wall.

hvacfreak

I do

[quote]But now, someone shows up and adds their motorized zone valves to piping that's leaving the steam boiler.[//quote]

A VERY wise man told me not to do that ( lol Dan H ) ...I'm talking air vent valves.

And I think a minimum " open " is needed as well. Just thinking out loud...my hoffman 1-a's are still like family ( more like inlaws ).

Bryant_3

Thanks for all the info I think I will back out of this one and let the two other companys bid on this. All the Pipe and Boiler is in poor condition to say the least. It will not take much water hammer before leaks start to occur. I made my recomendation leave what has worked great for a hundred years alone. I going to recomend to replace some of the leaking air valves. Again thanks for the advice and the help.

John Ewing

Zoning one pipe steam

This is a very interesting thread and I hope the experts will entertain a question from an interested bystander (a one-pipe homeowner).

It seems to be axiomatic that the the boiler should be sized and fired to match the radiation. WHen a large part of a system is zoned off, however, the boiler is now (apparently) oversized and/or overfired for that situation.

-- Are there adverse effects on the system in terms of control stability, steam and water dynamics, etc (assuming the system is properly designed in other respects)?

-- Can one anticipate fuel saving somewhat proportional to the portion of the system that is zoned off?

-- Does the mismatch between boiler sizing/firing and active radiation lead to an efficiency penalty that tends to offset the savings anticipated from zoning?

Thank you.

brucewo1b

Christian good thoughts

Depnding on the size of the system would it not be best to use two of those zone dampers by weil, burnham, peerless, etc they come in poer oil and gas configurations, and each would be connected to its own t-stat. I'm not saying that the price would be in the range of what they are trying to do, but if you talk with them about the down side to zoning with valves and explain how two boilers matching the load would be the best way, you might not get the job but when issues crop up down the line they will know whom to call.

Dan C.

article

thats a great article I could have used that a few months ago when I was trying to talk someone out of putting in zone valves

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Dan C.

what about if

you put in seperate boilers. As long as you know which returns go with which mains.

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Jamie Hall

a miscellaneous thought

gleaned from hard experience: if you do put a zone valve on a steam supply main, it MUST be a full port valve, and MUST be set to be either open or closed. Saturated steam is real weird stuff, and a partly open (or reduced port) valve will result in condensate on the far side -- and no steam.

Been there, done that... T-shirt is kind of dirty.

Steamhead (in transit)

Bump!

Thanks, Christian!

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