Newly nervous

Crisscross

Hello,

I was all content and happy with my steam heating system until I found this site. Now I am a nervous wreck. 2 years ago I moved into this to large of a house with missing doors and steam heat. The neighbors have the exact replica of our house and told us horror stories about the heating bill ($ 1,000.00 a month) and the other neighbors also offered there condolences in regards to the heating. Since I need only half the house I put some doors between the rooms, cut half the house of the steam heat and shut off half the cellar as well. Our heating bill is only $ 100.00 a month and I was all proud of myself. However, now I am reading about that the hissing and the water hammer and the short cycle is not supposed to be. I am worried my to big of a boiler will get damaged from the over firing and I am causing increasing damage. Here my question: How can a steam system ever be efficient. What if I only need to heat the bathroom at night. There is no way to run this monster in the basement efficiently. I ordered that green steam book but wonder if I should jump and add 20 more vents to the mainline?

Thanks,

Xoph

Al Letellier_21

igor in the basement

It certainly can be tough to tame the beast in the basement,  but you have to consider some things......#1 the system was probably way too big when it was installed, and #2 your trying to make it smaller without addressing the main problem.....the size of the boiler. It can be downfired somewhat and there are ways to make the system a little more user friendly, but you need some professional help. Find a good steam guy in your area and invest in some of his time to help evaluate the system and put a plan in place......Dan's books are great and have a lot of information, but in the field experience is needed also. Every system is different and needs its own plan for efficiency......you asked if a steam system can ever be efficient ??? You would get a resounding YES from us Wallies if you could hear us.....get some help and good luck.

Jamie Hall

Funny...

how a little knowledge can create total panic, isn't it?!  Been there...



But do not fear.  First off, steam heat can be efficient -- almost as much so as the very best of the very best of the modern hydronic systems, and better than most of them, most of the time.



However, as you are discovering, steam heat is not quite so forgiving to knuckleheads (not that knuckleheads can do hydronic well, either, but the results are less dramatic).



Before I continue, though, a word of warning about cutting houses in half, heating-wise: it may be problematic in the long term.  Be very cautious about excessively damp (even though cold) conditions in the cold half of the house.  This can cause mildew problems with books and furniture (if not outright mold) and the dampness can cause problems with plaster; not to scare you, but something to think about.



That said... (and I do agree with Al's comment about pro.s -- where are you?  Check the Find a Professional section, or just mention your location), there is much that can be done even with what you have, although I suspect that you will want to install a smaller boiler (assuming you keep the house cut in half).



First, hissing -- suggests to me that a) you have a one-pipe steam system and b) there is inadequate main venting, so the radiator vents have to do all of the heavy lifting and c) it is quite likely that the pressure is too high.  C is easy to fix; there is a pressure control on the boiler -- usually a pressuretrol.  It should be set to cutout at about 1.5 psi, and cut back in at 0.5 psi.  If it is a standard pressuretrol, that may be hard to get -- they are flaky at those pressures -- but set the outside scale at about 0.6 or 0.7 (I'll get to the short cycling in a minute; patience).



You don't need lots of main vents, but unless you have a truly strange system, you do need some.  Can you describe the layout of the steam mains in the basement?  Then we can help with suggestions as to how you might proceed.



You mention water hammer as a problem.  May I ask how you cut half the house off the steam heat?  If this is not done very carefully, just doing that can create horrendous water hammer problems -- as well as uneven heat in the remaining part of the building.  Can you describe how that was done?  There are other causes of water hammer as well; one of the most likely in an older house is pipes which have settled.  Every pipe must slope so that water can drain -- either back towards the boiler, or to some other pipe where it can drop to a wet return and get back to the boiler.  Otherwise, condensate will collect and hammer like crazy when the heat comes on.  Another likely cause of water hammer is excessive pressure -- but we talked about that above.



Now.  Boiler size and short cycling.  The boiler in a steam heating system, and its burner(s), must be sized to match the radiation which it is feeding.  If the boiler and burner are too large, they will produce more steam than the radiators can condense, so the pressure will rise and the burner will short cycle on pressure.  A little bit of that towards the end of a run is fine -- but not too much.  Having cut your house in half, you will need to cut the amount of steam produced in half, too.  As Al mentioned, it may be possible to downfire the boiler some -- a smaller nozzle in an oil burner, or tweaking the gas -- but there is a real limit on that, and cutting it in half is, in my opinion, beyond that limit.  You should get a professional person in, though, and see how far down you can go; it's fairly quick and inexpensive to do that, and will give you time to do a proper job of sizing, selecting, and installing a new boiler to go with the current house size.



However -- don't worry about the big boiler being damaged!  About the only way you could hurt it is by running it without water -- dry firing -- and that you are not doing.

bill_105

Dear Crisscross

If your not already a comedy writer, then you ought to be! The opening was great." My heat was fine until I found this site"?? Classic!! Then the rest was great follow up.  Seriously, All the best. You'll figure it out. Stick around.

Crisscross

Thank you all for responding...

I am glad to hear that the boiler is not going to be damaged. Yes, it is big and cranks out 205,000 BTU. And the worst - that thing is new: it's build in 2006.

 After I told my wife how I had saved us from doom by cutting off half of the system I also acknowledged that it would be as efficient as using a historic tank engine to travel 500 feet.  However I am very pleased with the energy bill. 

The work was simple enough. There was a 3" supply line going to the back of the house and another pipe that would return the water. The pipes are there a minimum of a 100 years and it was tricky to disassemble them. I just had to buy a 3" plug and a 1 1/2" plug. Actually, I was also replacing some other piping that was under the concrete floor and was corroded to the point of leaking. In fact I had to learn to cut pipes and thread. I just love it! 

As far as the system it is partly "one pipe" and partly "two pipe" The supply line forms a "U shape" with the "main - vents" on each end and the boiler in the middle. I don't think I can properly describe it.

I can't wait for that book. I would like to be able to heat what I need. Sometimes I need one room. Other times I need the whole house.

Well, thank you again for your help. I will be able to sleep tonight.

Best regards,

Xoph





 

Crisscross

Dear Bill

Thank you for your welcoming and encouraging words. I work as a stone conservator and stone carver. That's hard and dirty work but I love it anyway.

Xoph

Alan (California Radiant) Forbes

You must be a newlywed.

You told your wife what?

Charlie from wmass

You should start with

Got Steam not greening steam. wade in don't jump off the diving board. If you cut off the heat to half your house I would contact Jamie and talk to him as to how wise that may not be. Do not take this the wrong way but you need to be seen by a professional, Steamfitter that is.

Crisscross

Less nervous

Yes, I will have a professional check it out prior to the next heating season. As long as the boiler is safe - all I am risking here are $100.00 worth of vents. They are still working. The unheated portion of the house is in fine condition. It gets as low as 10 degrees and there have been no moisture problems. It's stuffed with books and paper - no curling there. I am planning to heat the space in the future - when I need it.

But I have another question to my boiler. It is fired with natural gas and I have about 5 burner pipes operating. Wouldn't it be possible to shut 2 of the pipes off and run the system on 3 burners? If that was possible, what would happen to the exhaust? Would it require a reduced flue size? Now that is crazy - I want to regulate the boiler- and flue size electronically, based on ever changing needs. An organ has different sizes of pipes, why not my reactor?

Xoph

Jamie Hall

It's not temperature

by itself which causes problems in buildings which are half heated, half unheated.  It's relative humidity.  If you can keep the relative humidity in that cold half below about 50%, your problems should be minor.  If not, speaking from experience with the building for which I am now superintendent/caretaker -- and owner -- you can run into difficulties.  They take time to show up, but in our specific case the repair and restoration costs directly related to the high humidity in the cold section are well in excess of a decade's worth of the fuel oil it would have taken to maintain a reasonable (low, but reasonable) temperature in that part -- a somewhat dubious lesson in economics.



One might think that it would be possible to reduce the firing rate in a boiler and, as I said in an earlier post, up to a point (depending on the boiler) one can.  However, as the firing rate drops, so does the efficiency and the probablility of problems, such as sooting, in the relatively cool sections of the boiler.  To use the argument of reduction to absurdity, consider what it would be like trying to heat a couple of gallons of soup over a candle -- it's just not going to work.  The only reliable, efficient solution to a 50% reduction in radiation is going to be a smaller boiler, matched to the radiation.



When you cut the pipes to the other section of the house, did you provide a way for any condensate in the ends of the cut pipes to get back to the boiler?  If this is a counterflow system, it may not be a problem, but if not, condensate collecting near those cut ends is going to give a problem...

Mark N

Just a Thought

You state that the output of the boiler is 205K. What's the input? How much radiation is in the house? Does it match the net EDR of the boiler? How big is the house? If I were you I would put the heating system back in proper working order. Relocate the tstat to a part or the house you don't use and set the tstat to maintain a min temp like 55 degrees. Maybe use space heaters to maintain a comfortable temp in the parts of the house you are using. Then assess the costs of heating this home. If it costs more that you can afford or what ever you'll be comfortable in paying I would sell and get something more affordable.

Life is stressful enough no need to be stressing about paying the heat bill and freezing at the same time.

Crisscross

Humidity in historic homes

Thanks, Jamie,

The back of the house is probably a 1800 timber construction with a center chimney. It appears to me that your historic house museum is constructed of solid masonry including sandstone. The horizontal water barriers of those often fail and the masonry sucks up the moisture. Masonry is also able to absorb much more moisture than wood and deliver it to the interior of the building. I am lucky in this regard. Also, the back of the house has not very tight windows and air travels in and out. Perfect venting. Once I insulate the walls, windows and ceiling of the back, it will be very affordable to heat. But I will not miss to install a direct vent with heat exchanger in the walls. I love breathing! I just measured the humidity and it reads 39%. Thanks for giving me peace of mind with the 50% number.

The condensate can flow back to the boiler. There is no trap. The supply line builds the described "U"-form and the return pipes on the ends of the "U" go down and bring the water back to the boiler. Consider what I cut off as an "add on". It left the "U" on the side and returned back to the "U" on the same side on the bottom and the "U" is perfectly happy without it. Only the bossy boiler is unhappy.

My home is comfortable warm (72 degree). The water hammer happens sporadic and not very often. The hissing is worst during the middle of the heating cycle. (That's when we interrupt the show and get drinks). I will replace the main-vents today and see what happens.

I am also wondering. If you calculate the heat loss of the envelope and size the radiators and boiler accordingly any change of the envelope will require at least a new boiler, a different flue size and probably new piping. As I constantly improve the envelope towards the goal of a "zero energy home" I am in constant purchasing mode for smaller and smaller boilers. How is this efficient?

Best regards,

Xoph



Thank you again,

Xoph

Jamie Hall

Actually...

the place I care for is one of those late 1800s "cottages" that folks built in the Berkshires (or Newport, RI, etc.).  All timber; centre section post and beam circa 1780 -- 1810; south end also post and beam, but ca. 1880, north end balloon, 1893.  Fascinating place, really.  The foundation is stone, of course -- huge granite and schist blocks of stone.



When you get that far, sensible heat exchangers are an excellent idea if the building is tight enough (I really don't like latent heat exchangers...).  I've worked with several solar heated buildings which use them for outside air exchange (we usually tried for 4 to 6 air changes per hour in those).



As to sizing boilers and steam radiation, keep in mind that steam is a little different from either hydronic or hot air: one sizes the radiation (number and size of the radiators) to the building heat loss, and then one sizes the boiler to the size of the radiation.  So if you don't change the amount of radiation, there is no need to change the size of the boiler, in spite of tighening up the house.  Nor is there any real need to change the size of the radiation -- all that will happen as you tighten up the house is that the boiler won't run as long or as often as it did before.  No loss of efficiency at all, nor of invested capital.

Crisscross

Steam radiator on wheels

Jamie,

You solved my problem. I will just roll the radiators from the back of the house to the front and install them there. This way the radiation will match the size of the boiler. Easy as pie. If I want to heat the back of the house I just roll the radiators back. All I need are shutoff valves and a few pipes. My boiler shall be happy.

I have a question in regards to my gas burners. Two of them are "missfiring" more often. What that means is that the fire does not start at the top of the small openings of the burner pipe but is actually in the pipe. I wonder how to adjust the pipe to avoid this from happening.

Thank you so much,

Xoph

bill_105

Careful out there!

Mess around with those steam pipes all you want. But the gas burning thing is something else. Like deadly?? I'm sure you have a CO detector, right ? It must be a huge mansion at 205k out. That's a lot of gas and nothing to trivialize. Really.