Balancing radiator steam heat system - 16 unit apartment building

bcoyle

Hi,

I'm loving this site! Starting to dive into how steam radiators work because I've been living in an apartment building that has radiators (no surprise, in brooklyn). All these years I've never taken notice to radiators as long as they weren't leaking I wouldn't touch them.

Recently had our shut off valves replaced since closing the old ones resulted in radiators that were still hot, and water drippage around the valves.

Now with new shiny valves, my focus has turned to the steam vents. I don't remember what originally were installed, but the last super had replaced them all with Hoffman 40s.

Last night the radiators kicked on for the first time. The short + tall one was making pinging sounds as it warmed up, I suppose just from metal expanding? Not sure if there is a solution to this. But all the radiators got hot pretty fast, and started venting quite audibly. There might have been a bit of sputter at the start but they would all just blow a lot of air. Then the system would cut and they'd stay warm for a bit before cooling. Maybe this is as perfect as it can be?

A few questions --

- Without knowing the rest of the radiator system, is it ok for me to experiment with different vent sizes to see how they affect each radiator?
- Is it possible to slow the heating process of the radiator via the vent size? This might help with the sounds of the metal being hit with heat so quickly. I'm hoping to fix the noise from the short+tall one since it's located in the bedroom. The pinging sounds are waking me up.
- Looking for confirmation with the shut off valves. They should always be kept open correct? Only when changing out the vent or maintenance should they be closed? Or can I keep some permanently closed because of too much heat or the noises they make?
- If the shut off valves should always be open, how can neighbors control the heat if it's too much for them? Would different vent sizes help?

Some pictures might help to get a sense of the sizes of these radiators
https://www.dropbox.com/sh/lxz2dsyree5gqnz/AACgkAiGNyFBkuheH3EsuKoWa?dl=0

I think that's the bulk of it for now. The information I'm gathering I might bring to the building to review. I know someone maintains the boiler, but I'm having doubts about their care in the rest of the system. And I'm pretty sure some apartments either have their radiator shut off valves closed, or have their radiators completely removed and capped off.

Thanks

Fred

- On a one pipe system, the valves should always be fully open, except maybe when a radiator is being disconnected.
- The pinging is most likely when the system has been off for several hours and the radiators are cold. There can be some expansion noise. Try cutting small pieces of a plastic milk carton and placing a piece under each radiator leg. That will allow the radiator to slide a bit when it's expanding and may help with the pinging.
- Make sure all the radiators have a slight pitch towards the valve end of the radiator so that water can run out and back to the boiler.
- You cn try different vents on the radiators to try to slow the steam down. It sounds like maybe the boiler pressure is set too high and that pressure may be causing the heavy venting noise. Not much you can do about that except try to get the building manager to set the Pressuretrol down to about .5 PSI Cut-in and the differential set to "1".
- If you want to try different vents, buy a few Hoffman 1A's or Vent-rite #1, http://www.hvacrsupplynow.com/VENT-RITE-1-STEAM-AIR-VALVES-ADJUSTABLE_p_1787.html they are adjustable and will allow you to play with the adjustment to slow and/or speed the steam as you desire (however pressure may still be a problem.
- If you want to shut a radiator off, turn the vent upside down. That will prevent air from escaping the radiator and hence steam can't get in, but leave the valve completely open.
- Make sure the boiler is not running when you change vents.

bcoyle

Fred, thanks for the comments! Few more comments as I continue to try and understand steam radiators. I just ordered three of Dan Holohan's books

- I ordered an adjustable Maid-o-Mist to test on the short+tall rad that is pinging. So I'll try swapping out bits to see if anything helps. Also considering a danforce thermostatic valve (?)

- When turning the vent upside down, are there any consequences to doing it while the radiators are running? Already today when I got home the apartment is 88 degrees and I wanted to immediately close one radiator up for some relief. I've heard there might still be a vacuum of steam in the radiator so it won't cool down. What happens then if I flip the vent back up an hour later? Right now I can't wait for it to cool down, it seems it is timed well to heat back up.

- Definitely plan to check on what pressure the boiler is running at.


I'm blown away that management told us to close the service valves if we didn't want heat. Today is the first time I learned that turning the vents upside down was the way to stop heat. In my 10 years living with these types of radiators!

nicholas bonham-carter

The vents presently on the radiators (Hoffman 40), are the best for slow radiator venting-just what you need.
Check out the pressure, which is where I think your problems start.
Ask your neighbors whether they have over heating as well.--NBC

bcoyle

Thanks for the comment NBC! - I'll be checking out the boiler this weekend. Taking photos and noting everything down there.

I know that at least the neighbors adjacent to me also think the radiators are too hot - they've turned off 2 of 3 with the service valves which has kept things under control for them. They're on separate risers.

Several units also have their radiators removed - so good chance the pressure is too high, and assuming every unit has their radiators.

I've turned the vent on one of my radiators - it was still warm when I did so. This morning it was cool - but warmed up a bit when the others kicked on. So probably another sign that pressure is too high

The radiator pressure is separate from the hot water, correct? I know our building has both the heat for hot water and for the radiators from the same source. It's an old system I have heard - since many buildings now decouple the radiator heat from the hot water heat for showers/sinks.

nicholas bonham-carter

It's ironic that the useless remedies they have applied have cost more than would have been the case had the correct action been taken. This does not count the extra 30% percent of fuel burned while keeping everyone in discomfort.
If the system is ever balanced, and made to run properly, what will happen to those apartments without radiators?--NBC

bcoyle

NBC -- since the building is a coop, we'd need to get everyone involved in keeping track of the radiators being used I guess. Possibly create a spreadsheet that does the balancing calculations if new radiators are added or removed. It does seem like a never ending hassle.

I'm going to try and figure out a solution but if it's not possible I'll get TRVs and be done I guess...

If the system is balanced, what is the expected heat output for rooms with radiators? Seems like still people will need to open windows since that was how the system was designed, no? Or they'd need to size down with new radiators.. or get radiator covers... radiator heating is interesting.

Still waiting for my books so a lot of this is probably covered.

BobC

Back in the early 20th century some steam systems were designed to heat the building with half the windows open on a cold night because of a fear of the flu that was rampant at times.

Over the years who knows how many people have laid hands on the system and half of them probably didn't have a clue about what they were doing. The whole system should be gone over to put it back to the way it was when it was installed, then adjustments can be made to make it work today.

Bob

bcoyle

Bob,

Amen to that. I've really been clueless to how these radiator systems work - and always assumed the people who come to check on the boiler would steer the whole system in the right direction, not just fiddling with the boiler.

This site has been an amazing resource. I can't stop going through various posts and reading about people's issues with their steam

KC_Jones

Just because it was designed to heat with the windows open doesn't mean it has to. With balance comes comfort. The building would have been originally designed to keep everyone comfortable windows or not.

The problem will be the system (with rads removed) has been redesigned to not be balanced. To fix it either need to put it all the way back to original or redesign all the units to accommodate the ones with rads removed.

They have (and probably continue to have) people working on it that don't know what they are doing. Replacing valves that aren't leaking to control heat was a massive red herring and complete waste of everyone's money. Overheating as you are doing, you might as well be using 20 dollar bills for fuel.

Overheating the whole building isn't a balance issue it's a control issue, they are running the boiler too much. This can be a result of poor balance to try and heat up cold units.

I may have missed it if it was asked, but where are you located? We may know a good steam contractor in your area that can help.

bcoyle

@KC_Jones thanks for the comment!

I'm in Brooklyn. It's a 16 unit coop building and I'm not part of the board so I can only relay what I learn and see what we might be able to remedy.

When you say the system is out of balance because of the radiators - is it possible to re-balance without adding radiators back? I know that along with missing radiators, there are also just new/different radiators than used to be in certain apartments. Mine for example has one that is original, with 2 others that look newer with less ornament.

Moving forward I want to present everything I've learned and see if there can be more transparency about what radiators people have, whether the valves are open/closed, and see if we can bring some balance back to the heating!

KC_Jones

There are always many ways to skin a cat. With the system possibly being "bastardized" an alternate solution could be TRV's, BUT you would still need to get the boiler controls in order. TRV's aren't necessarily a cure all as they need the boiler to be running properly to work.

I wouldn't just go putting TRV's on unless everyone was confident the system is basically as good as it can get without them.

coop and transparency....lol. Since they are spending my money, I would probably be very demanding and slightly less than polite.

Go to the find a contractor link on this website and take your pick there are many good steam men in NY.

MilanD

FWIW - with people turning radiators off and on, you are constantly (you, as in all the residents) varying the amount of EDR connected to the boiler. This essentially oversizes the boiler and for it to get heat to everyone, what previous maintenance people were doing was, probably, raising the pressure. This has in turn made things uncomfortable for people closer to the boiler, most likely. High pressure never turns off the boiler, and it's both massively wasting fuel and, from what you are describing, making your building a tropical paradise.

To alleviate all these issues, your coop needs to work with someone who knows what they are doing, to balance all the mains (pipes in the basement from which the radiator risers come up), and then also the radiators so that neither you nor anyone else will have to touch them ever. This may well become one of the residents with proper research and learning of ins and outs of your particular system. Regardless who does it, you need access to every radiator in the building for this to work.

While at it, survey them: picture of the front and SIDE, and dimensions, plus number of columns or tubes. This will let you calculate the proper EDR load - and see if the boiler is sized properly. Good info to have going forward for when the time comes to replace the boiler.

Proper temperature is 70F indoor in every room or whatever you all want it to be. This is achievable and do not let anyone tell you any different. On the 10,000 sq. ft building I manage, the last radiator farthest from the boiler gets the heat at a same time (actually, a little sooner) from the radiator closest to the boiler. Venting nudges the steam where you want it, and that's what balancing does: vent the mains in the basement evenly (or any other shared rad risers), then slow down rad venting a bit here and increase a bit there. Bigger radiators need to have a bit more venting and smaller rads need slower venting. Unless they have been moved around which is little likely, rads are sized for the room size and heat loss, bigger will need to emit more BTU thus, need more steam to get to them, thus faster venting, and smaller rads the opposite. This is a trial and error process, somewhat. You can calculate the volume of steam per radiator riser pipe and lenght, and radiator EDR (volume), and then length of mains (and risers) to help figure out volume of air that needs displacing and which vent goes where to do it, and how many main vents to use at a minimum. Mains need to be vented fast and first, radiators slow and evenly, which will depend on size of rad and size and length of riser pipes.

This link will give you idea on how Gorton suggests use of their air vents, and same can be done with maid-o-mists or vent-rites, etc:
http://s3.supplyhouse.com/product_files/G4S4product overview.pdf

Here's Gary Gill's chart on radiator vent capacities:
https://heatinghelp.com/assets/documents/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-1.pdf

NOTE: VentRite vents Fred suggested above DO NOT HAVE A FLOAT and turning it upside down will not stop the air from escaping. Hoffman 40 has a float and will do it: turning it around will stop air from coming out.

Lastly, you can always throw a blanket on a part of or on the whole radiator. It needs to be material that doesn't ignite below 250ish F. This will, in essence, insulate the radiator and reduce the BTU output into the space and is a cheap way to get the heat arrested under the blanket. Cheap and effective.

Do not be discouraged ever, as all this is doable - your system worked fine when it was installed, or who ever installed it wouldn't have been paid back in the day. Lack of knowledge about steam system is rampant. This board is a good place to come home to, with a lot of people generous with both the time and knowledge. Enjoy the process! -Milan

nicholas bonham-carter

Gorton's venting diagram is a slightly over simplified misinformation.
You already have the Hoffman 40, so the next step would be the adequate venting of the mains, and risers. When that has been done, the results of which can be seen on the low pressure gauge we recommend to everyone, then some rad vents may have to be made more capacious. As you have risers, that may not be needed, if the riser has enough venting on it.
Air is the enemy of the steam filling the radiators, and must be allowed to escape with low resistance, (back pressure).--NBC

ChicagoCooperator

My advice is get thee on the board (or at least the boiler committee - or create one if you don't already).

One thing I would note is that, like Chicago which I'm most familiar with, a lot of buildings in New York were thrown up quickly by developers and sometimes, the heating wasn't always up to snuff functionally much like in new construction today costs were cut and things were value engineered. I even have an article about it from around 1912 or so.

That said, you can do better, of course.

bcoyle

@KC_Jones, good points - going to hold on finding a contractor until I've read all the books by Holohan. Depending on how the board responds, I wouldn't mind being the go-to person for figuring this all out for the building, it's fascinating. Or at least I can direct the maintenance folks more with our precise needs.

@MilanD, Thank you for your post! So much good information. You mention that VentRite can't be flipped to shut off - do any vents close without having to be flipped? Also, do you think single size vents are best, or could we get away with adjustable? I have this crazy vision of apartments being able to all adjust their sizes accordingly on their own - maybe one apartment wants to turn a radiator off and then the units above/below could dial in vents to compensate?

But then again if the system is running properly then there shouldn't be a need for that. And the idea of covering the radiators to capture some of the heat - why hasn't anyone created a business around making customized radiator cozys!?

Wooden covers are more to prevent burning right? Seems like that's all I can find when searching for radiator covers.

@nicholas bonham-carter, venting the mains/risers should be interesting. I'm on the 3rd floor of 4 floors. There are no vents on the riser itself, so it must vent into the top floor apartment? I'll need to do more research and talk to someone on the top floor to see what their radiators look like. If they even have vents besides the one on their radiator. Is it possible to have a radiator at the end of a riser as the riser's vent? And if the top floor neighbor has his radiators removed... hmm.

Expect pictures this weekend of the boiler as I try to sort through what we have. I'm a 3d artist so I should try and make some neat mock ups...

Thanks all!

steamfitter

You mentioned cozy. Radiator Labs has this amazing product! There are significant costs due the custom making of the product, but you can now control your apartment without getting into the whole co op board issues.

http://www.businesswire.com/news/home/20120501006858/en/Radiator-Labs-Wins-200000-MIT-Clean-Energy

As some have already posted, venting the risers, and more importantly, the supply main in the basement are key. Rad vents should be quiet if all is functioning well. When you hear a vent hiss, it is a sign of a lack of venting in the riser (and possibly the steam main. If there is no vent on the riser in the apartment above you, that rad's air vent in the apartment above you, your rad's air vent and other below you, are taking on the job of removing air from the riser. That's why they would be audibly hissing and taking longer to vent, slowing down the steaming process and burning extra fuel with every cycle of the boiler's burner.
As you read Holohan's books you will learn all about how and why most steam rad's were purposely oversized and how some folks used special paint and wooden covers with metal grilles to dampen the heat transfer of these cast iron rads. Radiators use convection (as well as radiation to heat). A heavy blanket, as suggested, may be an inexpensive way to cut down the heating, but even if you cover the top, as well as the very bottom (where the legs of the rad touch the floor) with wood or even metal, you can slow down the convection and lower it's output.
The COZY, by Radiator Labs, is an insulating blanket and so much more! I was introduced to this product and the young student (at the time) who came up with the idea and ran with it and not one of Holohan's seminars.
Gotta Love that Holohan!

Good Luck with your research and work with steam. It so interesting!

Fred

@bcoyle , the Vent-rite #1 adjustable vent has an "off" setting, which is number "1" on the dial.

bcoyle

got some photos


overall front view

now I believe this boiler is also used for hot water in the building, along with the steam. Wondering if that changes things.

My guess is that the middle control is for the steam, the honeywell is at around 3 psi...

The other gauge is at 10 psi, possibly the hot water line?

not sure what the one on the far left is.

going to look for more material about this specific boiler this weekend.

cheers

Fred

The aquastat (far left) is for the hot water loop. Probably provides hot potable water for the apartments. The middle unit (gray box) is the operating Pressuretrol for the steam system. The scale on the front that is set at "3" should actually be set at about .5 PSI. That is the Cut-in pressure. (pressure when the burner will kick on) It is set way too high. Inside that box (take the screw out of the bottom front and lift the cover off) there is a white dial that is the Differential. That should be set at "1" or 1.5PSI max. That Differential pressure plus the Cut-in Pressure is the Pressure that the burner should shut off so that the system pressure never gets above 1.5PSI or 2 PSI max (.5 + 1 or 1.5)
The unit on the far right is also a manual reset for the boiler. If the pressure gets too high (as in if the primary Pressuretrol fails) , it will trip and that red button must be manually pushed to reset the steam system. It's set at 10 PSI, which for a manual reset is probably ok but I'd tend to set it at about 5 PSI. Most radiator and main vents can be damaged at pressures over 3 to 5 PSI.
Those pigtails (looped pipes under both the gray Oressuretrol and the manual reset tend to get clogged with crud and should be taken off and cleaned annually so that the Pressuretrols can actually see the system pressure.

nicholas bonham-carter

It looks like the sight glass tube is completely full, instead of being at the halfway point.
That higher water line leaves less room for the making of dry steam. Instead a lot of water will be blown up into the pipes, and if the main venting is inadequate, some of that water would be blowing out the vents, or collecting in the supplies causing water hammer.--NBC

JUGHNE

Agree with NBC. Also the indirect coils look to be valved off.

There must be a separate heater for the DHW?

Can you back up and take more pictures from all sides?

bcoyle

All fantastic comments - thanks guys. I wont bother the forum until I've received my books and done some reading. Also with the summer coming I'll have time to work on a detailed model of this boiler and the piping. Seeing it all laid out in the basement really shows what a complex beast it is. My apt gets 3 risers, so with 4 units per floor, there are at least 12 points in the basement where pipes are going up. Plus water lines. I spotted some Gorton #2 vents at some points in the basement. Still curious about what is at the tops of the risers.

Here are more pictures in the meantime






I believe this was installed recently because of hot water issues.

JUGHNE

This is a good study.....poster child for bad near boiler piping.
Study the Lost Art book and you will see.
Is there a condensate pump that returns the water to the boiler?

Does that indirect storage tank get water from the bottom of the boiler, (connected to the back of the boiler).... is the lower condensate water pumped thru the indirect heat exchanger?

bcoyle

@JUGHNE I wonder if there was more clearance between the pipes and boiler before they replaced it. I bet they replaced the older one with a larger one.

Good question about the storage tank. I'll need to look at this more closely. I know our hot water & steam come from the same boiler so I assume the storage tank is being fed from the bottom of the boiler. Not sure though about how it returns.

Maybe this also explains why the boiler's water level is too high? But yes, my The Lost Art of Steam Heating book is arriving today!

bcoyle

So I'm still going through the books - learning a lot - and trying to take notes on our setup. In the meantime, what are some negative reactions I could get from experimenting with air vent sizes? I assume a larger vent would spew water - but would a small vent do nothing besides slowing the heating process?

I'm a bit afraid because once I learned I could turn my Hoffman 40 vents upside down - they still heat up! The heat is more bearable. But this is certainly a testament to how much pressure is being put in the system. And it's not even a partial heating, but the whole radiator feels hot. It might also be that the system was partially engaged with heating when I flipped the vents, leaving a vacuum for the steam to get back in?

I have learned that our system does not have riser vents - at the top floors the risers ends with a radiator. I've read that in this case, it's better to have the lower floor radiators vent faster. So me being 2nd from the top, might start experimenting with a Vent Rite #1 to see if a smaller venting size would help with slowing the speed of the heating. Although I seems like the current pressure in the system doesn't even require venting...

The mains in the basement do have Gorton #1s or #2s in various places - not sure if they're all still functional.

The building now knows about my curiosity about the system so I'll be invited downstairs next time the boiler maintenance guy comes, so I can grill him

Oh one last thing. Service valves should always be open correct? I did come across some text in Mr. Holohan's book that mentions either open or closed - but I thought the consensus was always open. I want to make sure I can and should push for this.

Fred

On a one pipe system, supply valves should remain open because old valve typically leak some steam and the condensate can't get out of the radiator if the valve is closed. If the system pressure is too high, above 2 PSI max, you will have a very difficult time balancing your radiators. High steam pressure will ruin the radiator and even the main vents. Get the pressure down to a Cut-in of about .5 PSI and the Cut-out to between 1 to 1.5 PSI, then make sure the main venting is adequate and that those main vents work. Once that is done, then you can balance your radiators. Also, if the risers terminate in a radiator, you should be alright with no riser vent, if the heat is adequate. Each radiator on the riser will actually carry a portion of that venting load (air in the riser). Of course, if radiators on a specific riser are slow to heat (which doesn't sound like the case here) a riser vent will help.

bcoyle

@Fred

Tiny update. Was able to pick the brain of our boiler maintenance provider. He did not advise adjusting the PSI, which is currently around 3-4. He said .5 PSI would for residential homes.

Our boiler is also attached to this heat timer, http://cdn.heat-timer.com/wp-content/uploads/2013/01/EPU_Manual.pdf

So when I told him that everyone is too hot and keeps their radiator supply valves closed, he suggested adjusting the Heat System Sensor. Which was at 6, and we turned down to 2. This setting I believe is connected to a sensor attached to the return line. So we'll see what that does.

Another thing is that we used to get hot potable water from the boiler - but now have these Turbomax water heaters that fed right from the rear of the boiler. I might need to get more clarification on this because I thought the potable water would only enter the boiler via a heat exchanger and not be the water used in the boiler.... I could be way off on this.

Also for my own reference, why is it bad that everyone has their radiator supply valves closed? Does it just mean that the steam pressure will build up faster because there are less radiators to fill? Which makes the boiler cycle sooner? Not sure how I'll convince folks to open up their radiators unless they have another way to tamp down the heat.

Thanks

Fred

Also for my own reference, why is it bad that everyone has their radiator supply valves closed? Does it just mean that the steam pressure will build up faster because there are less radiators to fill? Which makes the boiler cycle sooner? Not sure how I'll convince folks to open up their radiators unless they have another way to tamp down the heat.
@bcoyle , your boiler maintenance guy doesn't know what he is doing. Running the system pressure at 3 to 4 PSI is way too high and the steam system doesn't know the difference between a single family home or an apartment building. The Empire State Building runs on less than 2 PSI of pressure. You just need enough pressure to get the steam to the furthest radiator and that is usually maybe 1 to 1.5 PSI. The .5 PSI is the "Cut-In" setting that allows the burner to fire when the pressure is at or below .5 PSI. Reaching the Differential of 1 to 1.5 shuts the burner down, until the pressure drops to or below the "Cut-in".

To your question about shutting radiators off, there are a couple reasons that you don't want to do that, on a one pipe system. The first reason is, the more radiators you close off, the more over sized you make the boiler for the remaining system. That, by itself will cause the boiler to short cycle on pressure multiple times during each heating cycle. Very inefficient.
The second reason is, with a one pipe system, condensate has to return to the boiler through the same pipe steam is delivered to the radiators. When you close a valve, there will still be some steam leak into the radiator (especially with old valves). That steam will condense and the water can't return to the boiler because the valve is closed. Before you know it, the radiators are banging because they are holding water and steam is leaking into the radiator, hitting those pools of water.

bcoyle

@Fred

Thanks as usual for your responses!

I wonder if this heat-timer is mucking up the boiler system then. From the manual it sounds like it is now the thing in control of starting and stopping the boiler, which is being based off temperature settings. Does that mean it's overriding the controls on the boiler? I'm going to contact the maker of the heat-timer control.

Maybe the high numbers for the cut-in/off are just so that the separate heat-timer system can do the on/off controlling. But is there a way to slow the startup pressure so that vents aren't hissing and spitting?

re: radiator supply valves
The inefficiency is probably someone nobody in the building will care about. Folks probably also won't care about the banging either... hmm. I was concerned that if everyone opened their valves it might floor the boiler, but apparently we have it setup to auto drain/fill to keep the boiler level.

If only my radiators wouldn't continue to heat up even with the vent closed. I could possible offer folks that if they open their supply valve they can install a vent-rite or maybe a thermostatic valve to control the heat.

The plot thickens with this heat-timer controller...

nicholas bonham-carter

The plot really thickens with over pressurization, and inadequate venting. Naturally when it doesn't work properly, the "so called maintenance guy" thinks a heatimer will fix everything.
If your brakes are dragging, do you just drop a bigger engine in the car?

bcoyle

@nicholas bonham-carter lol

I talked to a Heat-Timer rep and it doesn't seem like making any adjustments to what is essentially a thermostat is going to solve the high pressure situation. I just wonder how long our boiler has been at this setting...

The rep did give me a process for how to correctly calibrate the heat system sensor dial. Essentially you run the boiler until the furthest radiator starts to get hot and then you dial it down until the 'heat circulation established' light pops on. Wonder if that was ever actually done or they just picked the number 6.

Having a thermostat control the boiler, does the pressuretrol cut-in actually do anything? seems the cut-out is what I'd need to lower since the thermostat will tell the boiler to just start no matter what pressure it's at. Or is it the high cut-in that is causing such a push for the air to escape?

Fred

Regardless of when the thermostat calls for heat, the Pressuretrol Cut-out will shut the boiler down when the system pressure reaches that approximate pressure. It will allow the burner to kick back on when the system pressure drops to (or just below) the Cut-in pressure setting if the thermostat is still calling for heat. You really need a low pressure gauge (0 - 3 PSI) on the boiler to determine if the Pressuretol is properly calibrated and you need to make sure the pigtail (looped pipe) that the Pressuretrol is mounted on is not clogged. If the Pressuretrol is out of calibration, there is a procedure to re-calibrate it. I can post that, if needed but again, you need a low Pressure gauge and to clean the pigtail first.

nicholas bonham-carter

The heatimer is a bit like cruise control for temperature only, using as its compass heading the outside air temperature. It should have an internal sensor to make some sort of correlation with the interior comfort level. When they are installed by the unknowlegeble technician as a solution to over/underheating, they frequently make the situation worse, but by the time that has happened, the check has been cashed. The only plus I can see in such a system is its ability to be unaffected by people who keep their windows open in winter while the system is over heating.
My 7 unit building with 55 radiators-one pipe steam system, pushes the air out with only a couple of ounces of pressure. Its pressure is limited by a Honeywell Vaporstat set to cut out at 10 ounces of pressure, which would only be obtained in times of prolonged firing as the temperature hovers at design temperature. The boiler was sized properly to the combined total of radiators, (EDR), which yours may not have been, if installed by the same people you quoted.
I use a thermostat with internal sensors placed in the two most exposed rooms in the house, and can switch between them as conditions change.
Over the summer, concentrate on increasing the main venting, installing a vaporstat, and a low pressure (0-3 psi) gauge. While winter comes on slowly, you can try to adjust the heatimer, or replace it with the sort of thermostat I have with remote sensors.
Do a search here for a real steam technician in your area if you need help. Spending the equivalent of a few months fuel bills would work wonders.--NBC

Dave0176

The near boiler piping is terrible, there's really no header.

bcoyle

@Dave0176 I'm going to measure the header height today. The manual states 24" min which seems standard. Also need a 6" clearance from the ceiling. Damn this basement.

I just did a super rough calc on the overall BTU. The boiler is spec for 1,029,000 BTU gross, 80% efficiency (so about 823,200 BTU output) - my apartment needs/uses 18,120 BTU for three radiators. If I just extrapolate that across the building (16 units). That would a total need of 217,440 BTU. Plus I guess you should add more for heat loss. But, uh. What.

Plus this boiler is used for hot water, not sure if that needs to be taken into account in any way.

Fred

@bcoyle , I think your calculations for your radiator EDR may be wrong, unless they are all very, small radiators. A picture of the typical radiator would help, also height from floor to top, depth from front to back and the number of sections on each radiator. If they are convectors, we definitely need pics.

bcoyle

@Fred Here's one radiator example, http://i.imgur.com/koNZGH4.jpg
This is the living room radiator. Here's my calculation -
26" height, 9 sections, 5 Tubes, EDR chart gives me 3.5, 3.5*9 sections=31.5, 31.5*240, 7560 BTU designed output? Then I have smaller radiators that are 5,760 BTU, and another skinny one that is 4,800. All pictures here, http://imgur.com/a/wLvHm

If the boiler is also used for hot water, do you size the boiler differently? Maybe that's why it's larger than needed for the radiators. But then it seems strange that we've had hot water issues and needed to get an external indirect water heater.

@Dave0176 measured the header. You're right it's too short! 24" minimum is required and 24" is right at about the bottom of the water sight glass... last time I checked the boiler the sight glass had the water slightly above the middle. Maybe if the boiler water level ran at the middle or slightly below it would be a bit better... sigh. No idea how this would be corrected or the cost. I might try and 3d scan the whole mess of piping above the boiler to visualize. Sucks for our building, but our sister building looks to have more than the minimum header on their boiler. Not fair!

Fred

@bcoyle , your calculations for the radiator EDR is correct. I assume these are fairly small apartments. Are you sure they are all the same size, with the same size and number of rads? The boiler size should not be increased for the tankless water heater. When the boiler is running to heat the building, it should be able to heat the water passing through the coil and when there is a call for hot water when there is no call for building heat, all the boiler has to do is heat water. Adding the indirect tank suggests there is more demand for hot water (at certain times) than the capacity of the tankless coil to supply. It is also possible the coil is limed up and has a restricted flow.

bcoyle

@Fred Yes it's totally possible that some units have a 4th rad, and there are definitely different rads in every apartment. But I don't think they could be that much different. Even if I calculated all apartments having 4 of the largest rad that I have, the total need is still around 400,000 BTU. So our boiler is almost double what we'd need. I plan to get a more accurate reading on the amount of radiators we have in the building - although it might be a struggle.

As for the hot water, that's a whole other topic I need to dive into later.

Back to the books for more studying--

bcoyle

Wanted to share a 3d scan I did of our boiler - https://skfb.ly/6rTBK. There's a red marker showing 2ft from the waterline so you can see where the header sits.

The plan is to use this as a reference to properly 3d model the size of the boiler and all the piping. I'll be doing back down to get exact pipe sizes, but this scan gives me general layout to start.

At this point I've got a decent understanding of the workings of steam heating, but will keep reading over the summer and eventually get in touch with our current boiler tech to ask them questions. I need to know how best to explain to residents how we can control the heat in rooms that get too hot. I might simply be that we get air valves that can be turned off.