Is my steam boiler way oversized?

livinthesteamdream

I just made it through my first winter **glad it was the worst I've seen in nearly 2 decades** in an old house with steam heat. Although I love the heat from my steam radiators, I hate my oil bill. ;)  This got me researching steam heat leading to this site and Dan's books. The house is a large historic home with 25 radiators with a 2-year old Burnham V908 supposedly rated at 1,000,000 BTUs an hour. After fixing several return leaks that were causing it to short cycle and feed water, and some work by some good steam pros I found here, it's now only short-cycling due to pressure...a lot! I measured all the rads for square feet of EDR, and found my total to be 1,443.3 for the entire house. If I'm doing this correctly, I multiply that by the 240 BTUs/sq ft of EDR giving me a required boiler size of 346,392 BTUs. Do I then need to multiply that by the 1.33 pickup factor for steam bumping that size up to 460,701 BTUs? I'm trying to get an idea of how oversized I am and what options I have.

1) Am I right in the boiler size I need? 2) If so, am I pretty much looking at having to yank the 2 year old boiler and start over since it seems to be 2-3 times larger than it needs to be (if I'm figuring this correctly)?3) Is there anything I can do that will lead to moderate efficiency despite the oversizing?

Any assistance is appreciated, and if you need more pics or information just let me know.

livinthesteamdream

and yes...

I realize the near boiler piping is terrible! They apparently re-used the old header pipe...and didn't really know what they're doing.

SWEI

Simpler

V908 is rated for 2,888 square feet of EDR.  You have 1,433.  Your boiler is twice the size it needs to be.

nicholas bonham-carter

Down rating the burner?

If you can find a good steam man, or burner man, maybe the burner could be derated a bit for some savings.

Even more important would be making sure the air can get out through the main venting system.

Is this a 1-pipe, or 2- pipe system?--NBC

livinthesteamdream

if this was your house

What would you do with this boiler? Try to sell this & replace it with a properly sized boiler? Is there a market for a used boiler such as this? This was installed by a local company a year and a half before I got the place so its only 2.5 years old. I was purchasing roughly 600 gallons of oil from them each month with it set fairly low at 58-62 due to issues stemming from the oversized boiler and improper piping resulting in a ton of water hammer. I'm just trying to ensure next winter isn't this uncomfortable & expensive.



The most local pro I found here addressed venting with the addition of 2 Gorton #2s, a #1, and replacement of 2 crossover traps. Oh, they added a vaporstat as well.

livinthesteamdream

2-pipe

I forgot to mention that in the last post, NBC.

nicholas bonham-carter

Dealing with oversized boiler

I would try to get the supply piping straightened out first, and make sure with a low-pressure gauge, that the venting was adequate, (I have 18 Gorton 2's on a 1,050,000 boiler with 55 rads).

Was a combustion test ever done? Is the burner 2-stage?

A boiler that big is difficult to move without complete disassembly. If you were to replace it, a pair of smaller 200 MBTU boilers, staged on pressure, might be more economical.

Is gas available?--NBC

livinthesteamdream

burner

The burner us a Beckett CF1400 running a 5.5 gal nozzle. It will accept down to a 4 so should that be the first change? I haven't had a combustion test done since I've owned it. I don't mean to be stupid, but I don't know about the 2-stage part. The specs mention a Linkageless Low/High/Low feature. Is that what you're referring to?



We do have natural gas in the area & I have a meeting scheduled with the local supplier on Monday to see if that would be feasible. Without getting into price, the conversion for this was moderately costly considering all the other issues I still have to correct with the steam system overall such as near boiler piping, venting, pipe insulation, etc.



I almost feel like I'm just throwing money away.

SWEI

You might

be able to remove some sections when the repipe is being done, and end up with a V-905 when you're done.



Installing a smaller oil burner will cost almost as much as a NG conversion burner would.

livinthesteamdream

removing sections?

First of all, I want to thank all of you who have posted thus far. I really appreciate your insight & assistance through this process. I had wondered if removing sections was a possibility, but I didn't want to sound (really) stupid. So that is actually feasible? If the smaller oil burner is the same cost then cheaper NG is the way to go...assuming it is available to me. What all does removing those 3 sections entail?



What is best overall game plan I have to not have to install a new boiler or completely abandon steam heat? I do still like the steam heat & the fact that I'm using the original 100-yr old heat system in my historic home. I just want it to work properly and as efficiently as it can so my family can be comfortable.

Jamie Hall

No need to abandon

the steam heat!



Removing sections is a bit of a hassle -- I wouldn't call it a do it yourself project, by any stretch.  However, it certainly isn't impossible.  A good steam contractor (look in Find a Contractor, by State for one near you -- or just tell us where you are and we may know someone) could do it, and at the same time tidy up the near boiler piping and, if you find you have access to natural gas, install a gas burner.  All at the same time...

livinthesteamdream

10-4 on the pro

I have reached out to local pro I found here, so I'll definitely not be attempting this on my own. I'll have get an idea of cost for all of that. I'm just glad I wouldn't have to completely start over due to the oversizing deal. I was worried about that.



Any other ideas of how to make this work?

heatpro02920

If I were doing the job

I would try to talk you into getting NG if it is available first off... {check costs to bring in service and make chimney work}...



Then I would contact US and see what the cost of new rods, jacket side panels, seal, ect looks like.



Then contact Carlin for a gas burner...



I would also repipe everything in your pictures, and insulate EVERYTHING.. Get the piping rite for what is there, kind of a start over and see where it ends up job, nothing I would tackle in the winter months, but now you should be good to get the research done, find the rite pro and be happy with your 100 year old heating system..



There is a market for that becket burner, ebay would be the best place to unload it if you can not find a buyer here on our classifieds and your contractor isn't interested...



good luck, looks like a fun project..

livinthesteamdream

good info

Thanks for the information heatpro! I'll be finding out about NG this coming Monday when I meet with Mountaineer Gas. If I downsize the boiler to 5 sections (V905), what size NG burner would I be looking at for this setup? I'll try to get some cost info together.

heatpro02920

Burner size

I would call Carlin {I am starting to use them more and more}, or maybe a Power Flame J15 ... http://data.powerflame.com/support/supportdocs/Catalog/pdf/type-ja/JAHTD-Bulletin.pdf

or http://www.carlincombustion.com/gas-oil-burner-products/burners/commercial-burners-gas-fired/201-gas-burner/ I just ordered one of these for another job...

I think I would lean towards the carlin, but make sure it will be ok in that boiler first, I never personally installed that one... Tim McElwain under the gas topics would be the best to tell you which burner to use, that is who I would call to ask... He has probably installed one or knows of someone who has already in a similar situation...

livinthesteamdream

burner post added

Thanks again heatpro. I just posted the NG burner question on Tim's gas page so I'll see what he has to say. Man, this seems like it's going to be a ton of work....cut a pretty much new boiler in half, repipe it, convert to natural gas and pipe that in, add venting. add insulation, trace leaks, etc

The Steam Whisperer (Formerly Boilerpro)

Probably a litle more sane approach.....

would be to first convert to natural gas and simply fire the boiler at the proper rate.  Most gas fired boilers seem to work fine with a 50 to 60% down fire, in fact Burnham probably has this as a factory approved high/low set up for the boiler.    Properly tuned, you'll probably see a 3 to 4% increase in firing efficiency when running at these low fire rates.  In this case, you want to keep the boiler oversized to gain heat exchange efficiency, but cut the firing rate.

Over your current set with oil, you'll probably see at least  60 to 70% drop in fuel costs just making this change due to much cheaper natural gas, and much more efficient boiler and system operation.

Also, now that you have a huge boiler with a small fire, the need for correct piping above the boiler drops dramatically because the water and steam will separate much better inside the boiler and there will be much less reliance on the external piping.

This will buy you some time before rebuilding the header.

livinthesteamdream

that would be much easier

I wasn't aware that you could do that much of a downfire, but that would be way easier of a progression for me! I had tried to call Burnham yesterday but they'll provide no support since I'm not a contractor. Should I find the closest dealer to get the information I need in regard to which burner to use in this setup for that downfiring rate and naturally cost? Or can you suggest a burner? The Carlin 201 says its from 150k BTUs to 399k BTUs so I was thinking the Carlin 301. Anyone know about the Carlin EZ model? Then, if I can find a local burner specialist I could be set. That buys me time to get the header redone as well. However, I would like to try to have all these issues resolved by next winter. I'm currently not using the boiler anyway despite the temperature still being chilly so if I could get the burner done ahead of time I could actually test it out this spring. My wife would love to not be cold!

SWEI

Mountaineer Gas

is in West Virginia.  Don't recall any pros hailing from those parts posting here, but I haven't been around all that long.



"Nearest dealer" is pretty much a crapshoot.  Better to find someone with proper conversion burner training, hopefully with some steam background.  Tim McElwain might have someone he can refer.

Tim McElwain

Oversized for sure

My e-mail answer is below to SWEI who contacted me about this posting I also got the message over in the gas section, I do not know anyone in the W Va. area but will look into it.





Not off hand I will look into it. I am getting ready for a class so it may take a while (it is getting warm hopefully). With Burnham getting info when the word conversion is mentioned is tough. I have in the past with commercial boilers knocked them down a couple of sections (a lot of bull work). Cost begins to be a big factor Dave Brunnell had a good idea for a temporary fix so the customer can budget things out.



Daves answer:



Probably a little more sane approach.....

would be to first convert to natural gas and simply fire the boiler at the proper rate.  Most gas fired boilers seem to work fine with a 50 to 60% down fire, in fact Burnham probably has this as a factory approved high/low set up for the boiler.    Properly tuned, you'll probably see a 3 to 4% increase in firing efficiency when running at these low fire rates.  In this case, you want to keep the boiler oversized to gain heat exchange efficiency, but cut the firing rate.

Over your current set with oil, you'll probably see at least  60 to 70% drop in fuel costs just making this change due to much cheaper natural gas, and much more efficient boiler and system operation.

Also, now that you have a huge boiler with a small fire, the need for correct piping above the boiler drops dramatically because the water and steam will separate much better inside the boiler and there will be much less reliance on the external piping.

This will buy you some time before rebuilding the header

Tim McElwain

Maybe Steamhead

would make a journey over into nearby West Virginia if the price is right.

Steamhead

We did

and the OP says it's running better after some repairs we made (vents and crossover traps), but still using a lot of oil. This is a Hoffman Vapor system.



One thing to be determined is whether enough gas is available from the street main to fire that boiler. Then we'll know if converting is even possible.



We did not open the boiler when we were there to see how dirty the fire side is, but given what we usually see, I expect it would take several soot-vac bags to get it clean. We just ran out of time that day.



But there's nothing about this system that can't be fixed.

Tim McElwain

The last few jobs

we did with low pressure available from the gas supplier was to install a large line running from the meter to the boiler. In one case it was about 45 feet of 3" welded pipe. That unit and the others are running fine with no problems this winter. All of those boilers were HB Smith two of which were in churches with 1,250,000 on one and the other 950,000 BTU's. All these are steam using Power Flame combination oil/gas burners with low fire high fire adaptation. All you need is money!



All of these jobs have seen over the last three years 25 to 30% reduction in cost to operate and the 1,250,000 has seen almost 50% as it was originally only set up on oil to run on low fire, that gets expensive. The church actually paid for the entire installation with the savings on fuel costs the first year.

Jason_13

L/h/l firing

In the meantime doesn't that boiler have a low fire hold switch. That would reduce it by about 40% until the gas comes and should still heat well.

livinthesteamdream

yes to the low hi low feature

But Idk how to set that up. Is it a pro type job or are there steps to follow?

Dave in QCA

For What it's Worth

Just wanted to let you know that I have an oversized boiler similar to yours, except mine is a Weil-McLain 680. I really only needed a 580, which will allow for future restoration of parts of the steam system that are not currently connected. Because I wanted a 2 stage burner, and WM had only approved a 2-stage burner on a 680 and larger, that is what I ended up with. At the present time, it is firing on Low Fire, a little less that 50% of its full rating. It works great! 82-83% efficiency and 34% less than my old gas boiler.



As a general rule of thumb, most power burner boilers can fire at 50% with little loss in efficiency and sometimes, actually more efficient that firing at 100% of capacity.



As second benefit, it doesn't work the boiler near as hard and you'll probably find that it will have a longer life as a result.



If it were my boiler, I'd convert to gas and tune the thing at 50% of it's full rating ASAP. I would not bother taking sections out, it's too much bother and cost (new jacket panels) and not really necessary.

livinthesteamdream

sounds like the plan

Thanks Dave. That definitely sounds like the way to go. I'm hoping I hear good news about the gas supply Monday. However, it seems as if even low pressure supply may still be ok assuming I size the pipe from the meter in sufficiently. Does anyone else have positive experiences with low pressure NG running a boiler of this size?

Tim McElwain

I have commisioned well

over 100 boilers all of which are in the inner city with gas pressures in the mains of less than 1/2 a pound pressure. Most of the mains run 8 to 10" W.C. pressure all the time. In extreme low temperatures the pressure my drop down to 5" W.C. but piping is sized from the meter to the boiler to compensate for that. Your installer of the gas line should take that into consideration when sizing the pipe from the meter to the boiler.

livinthesteamdream

So I should be good then?

Thanks for the expert information, Tim. I appreciate you weighing in on my situation. So it sounds like if the piping from the meter into the boiler is sized properly I should be good regardless of whether or not the NG main is delivering high or low pressure, correct?

Tim McElwain

Make sure you get a good steam tech

to do all the piping and combustion set up along with a combustion analysis.



On low pressure main systems you will never see high pressure. High pressure systems range from 25 pounds to 100 pounds pressure then reduced to less than 1/2 a pound at the internal regulator before the meter.

The Steam Whisperer (Formerly Boilerpro)

Low gas pressure

Chicago is almost all low pressure mains and we have lots of really, really big boilers. Typical courtyard buildings are running 2.5 million to 3 millions input boilers and 500,000 btu input water heaters, all off low gas pressures.  The key is sizing the gas piping correctly. 

livinthesteamdream

I just met with Mountaineer Gas

and they said that they provide 7 inches w.c. and up to 2 PSI which would require a pressure regulator. They're even willing to trench and move the meter to the left side of my house to keep it off the front and eliminate roughly 50-75' of pipe I would have had to run in to my boiler room! Additionally, their availability to do this work was excellent.

Now that I'm good NG-wise, what burner should I use? I know the Carlin 201 is 150,000-399,000 Btuh, and the 301 is 401,000-1,100,000 Btuh. My boiler is currently the 1,000,000Btuh, but it the more appropriate size figuring square foot of EDR with the 1.33 pick up allowance for steam was around 460,000Btuhs.

OR, would a PowerFlame burner be a better option? What have you guys seen as far as gas burners. I'm trying to sort everything out burner-wise keeping my currently twice the size boiler.

Also, MG mentioned using 1" steel pipe from the meter to the boiler? Does that sound right? My guess is around 30' of piping with all the bends...

The Steam Whisperer (Formerly Boilerpro)

go to the Burnham site

and check out what the factory gas burners are for those boilers. 

Steamhead

One-inch pipe won't cut it

unless they figure on the entire gas distribution in the house running at 2 PSI, and even then I'm not sure. Have to look it up but I'm not at the office.



Burnham offers Beckett and PowerFlame burners for the V9A series boilers. PowerFlame would be the better bet, since they offer lo-hi-lo firing in smaller burner capcities than Beckett.

livinthesteamdream

1" did seem low

considering the way everyone wrote about proper sizing from the meter to the boiler. I'll await your guidance there, Frank. One question, though...although my boiler should really be in the V904-V905 range, we will use the PowerFlame burner setup for my actual boiler (V908) and downfire with the low high low feature? Is my understanding of this process correct? What else is involved in that setup?

livinthesteamdream

Is there any downside

to a combination gas/oil burner beyond what I assume to be a higher price? I see PowerFlame has those as mentioned in the Burnham manual.

Steamhead

That's what I'm thinking

the combustion test will determine how low we can go. We don't want to get the stack temp so low that the flue gases condense inside the chimney.

Steamhead

It would give you some flexibility

but switching fuels on such a burner might take more than opening/closing valves and throwing a switch. We'll have to look at this more closely.

Tim McElwain

The nice thing is that

on Power Flame it is simply a matter of throwing a switch to change from one fuel to the other.

livinthesteamdream

That would be nice!

I have a contractor friend who was tearing out an oil tank. Consequently, I was fortunate enough to get about 180 gallons of oil for almost half the cost I was paying from the local oil company due to a person who had filled up but then just replaced the system. That kind of flexibility would be nice just in case I ran into another situation like that. It isn't everyday, but it's nice to take advantage of when it does happen.

BobC

Don't try to store oil

for much beyond a year. The new heating oil is not stable long term so It should be used up in a reasonable amount of time.



When I installed the Smith G8 / EZGas boiler I knew I always would have the option of going back to oil if anything happened with natural gas  cost long term. I'd have to buy an oli gun and get a tank but the option is there.



Bob