Insulation, vents, and a cold room

EHurley

Hello Heatinghelp community,



This is my first post, I am hoping to get a little advice on my steam heating system with an eye towards gaining more efficiency. I have been reading "We Got Steam Heat!" as a primer to familiarize myself with my system so I can (hopefully) speak intelligently about what I have in my system.



My house was built in 1895, it is 1,246 sq ft.

I am in New England.

I have been in the home for ten years.

I have a steam by oil system, I had an oil company replace the boiler about seven years ago, it is Weil McLain SGO-4.

The home has six radiators: five on the first floor, one on the second.

System is one-pipe, some of the branches have condensate return pipes below the main, two do not.

I have no proof, but I suspect the system was once coal fired (digging in the yard when we had the deck expanded revealed layers of coal), and it may have been converted to gas (my evidence is an old gas meter and remembers of pipe leading to vacinity of boiler) and then finally to oil.

The asbestos has been removed from the piping.

I have removed and boiled the radiator vents in vinegar, hoping to remove any blockages.

I do not appear to have main vents, I don't even appear to have a place where they would have been and had ben subsequently capped. This leads me to believe that this system is like ones I've read about that rely on heating the far away radiators quickly, and the nearby radiators slowly



My to do list has become:

Insulate piping

Replace radiator valves if the boiling does not improve their performance (some have made sputtering and hissing noises)



My questions:

1) I want to wrap the steam pipes in insulation, I have clearance issues with the joists in many places. I have only 1/2" clearance in places along the mains. Though I know at least 1" is recommended, but believing even 1/2" is better than nothing, is it worth mixing and matching along lengths of pipe between 1/2" and 1" where it can fit? would mixing insulation thickness case issues that would make it be best to go all 1/2"?

2) I have at least one place where two steam pipes are very close together: is it acceptable to wrap these together within insulation (I'm thinking some sort of "blanket" around and between and then wrap with tape)?

3) I have one small section of pipe where the iron steam pipe connects to a smaller length of copper pipe for a short distance and then runs into the radiator: can/should this pipe be wrapped in fiberglass as well?

4) I also have a copper pipe touching a main in one spot, I'm thinking the main should remain uninsulated in that one spot my thought being that you can't insulate these two pipes together?

5) most of my radiator vents are adjustable, the thermostat is in the living room, but there is a small radiator in another room on the first floor, which I believe was once a porch that was made into a room. This room has cold issues, it is very hard to heat and is often very cold. The radiator does heat up, but does have some water hammer. The walls have been checked and are insulated, I have someone coming in to lay a vapor barrier on the dirt floor of the crawlspace beneath this room and also install foam board on the joists over the existing fiberglass batts. I'm hoping that the combination of insulating the steam pipes and remedying the crawlspace beneath the room, along with setting the radiator in the living room, where the thermostat is located, to vent more slowly, will help this room become less cold. Does this sound reasonable approach? (This is the smallest and looks to be newer than the rest of the radiators in the home, which makes sense if this room was not originally part of the heating system.)

6) The radiator vents are a mixed bunch, I have several Vent Rite #1 adjustable vents. I also have one that attaches from the top: tongue and threads are out the bottom (labeled Vent Right #51), this particular one is attached via an elbow attached to two small "pipes"). Is it worth the expense to replace this Frankenstien vent and one other nonadjustable one with new Vent Rite #1s?



Thank you very much, for any input you may be able to provide, take care.



Sincerely,



Ed

Danny Scully

Hello Ed

Hello Ed, glad to see you're educating yourself on your home's heating system. From reading your post, I feel as though your home may have been built without a heating system. I'm only making this assumption because of the age of the home and the odd configuration you're describing. Nevertheless, your plan of action is needed. In regards to insulating the piping, any insulation is better then no insulation, no matter the thickness. Obviously the thicker the better, however, I see no major issues with a variation of such. As for the sections of copper piping, they're are not ideal but if they're not leaking or appear as though they have, then insulate them as well. As far as the radiator vents, I'm sure most of us would agree vent rites are not the greatest. They may be advertised as adjustable, but in reality, they have one position, wide open. If you're really gearing towards efficiency I would recommend thermostatic radiator valves, of TRVs. These valves are amazing and act as their own thermostat. I personally like Danfoss TRVs with Gorton vents. If this is not within any budget you may have assigned to this project, or if they are not appropriate for the radiators you have, I would recommend properly sized Gorton vents. There is a great book available on this website called Balancing Steam Systems Using a Vent-Capacity Chart, by Gerry Gill and Steve Pajek. This may be a bit technical but you sound determined so I'm sure you'll figure it out. A few other things you might want to look into is your boiler's near boiler piping, and adding main vents. Near boiler piping is crucial in the production of dry steam, and similarly, main vents are important in allowing that dry steam to move. I know there may not seem like a spot to install them, but that doesn't mean they can't be installed. If your not inclined to cut in a tee on the main, considered drilling and tapping the pipe directly and installing a main vent there. Hope this helps.

ChrisJ

insulation thickness

I have one small section where two steam takeoffs run very close to floor joists.  One of these is actually almost touching a joist as the floor had sunk quite a bit.  Best part is someone had drilled a hole in the pipe to let the water drain out instead of fixing the problem.  When we replaced the pipe I quickly found out there was a pitch problem.



I'm using all 1" thick insulation and in the situation where these pipes are near or even almost touching joists I'm simply going to notch the insulation around the joists. 

nicholas bonham-carter

Venting problems

My own radiator vent preference is gortons. You would benefit from main vents, and it may be worth the effort to find a way to put them on the dry returns; however you can often achieve somewhat the same result by putting a gorton d on the radiator at the end of the main and see if there is improvement. If you use any setback, keep it within a couple of degrees. The rest of the radiators should be more slowly vented.

If there is inadequate clearance between 2 pipes, then you can certainly wrap them as one bundle, as you are trying to prevent the steam from fighting cold metal every time it comes on.

Have you checked the anticipation of the thermostat so it is set for stem. Some new thermostats are not able to be set for steam, and should not be used.--NBC

BobC

90+ year old house here

I'm not a pro but I've lived with steam heat for over 60 years and done most of my own repairs for 30 (but not on the combustion side). It would help if you could take pictures of anything you have questions about because a picture really is worth 1000 words.



Insulating as much of the steam main as you can will improve performance and save fuel. I bought the 1" rigid fiberglass pipe insulation (not cheap) and installed it myself and is really helped save fuel and tame things down. My house is 90+ years old and I had a couple of spots with little clearance so I wrapped these spots witth kraft faced wall batt insulation, those spots were only 8-10" wide so they don't have a huge impact.



Running the system at very low pressure helps everything work better. When my pressuretrol got flaky I replaced it with a vaporstat and now run the system at 12oz's instead of the 2 PSI on the pressuretrol - this is not cheap and I would do it only if you have to replace the pressuretrol. I also replaced my thermostat with a Honeywell that does a great job with steam. I'm retired now and use a staged recovery so the system comes up in two stages, first by 3 degrees and later by 2 degrees. no bangs or other strange noises.



Make sure all the pipes in the basement are sloped so water can find it's way back to the boiler. Old houses sag and sometimes one or more radiator runs (or the steam main) end up with a dip or end up sloping the wrong way, don't depend on your eyes use a level. Any banging is usually caused by trapped water because of a dip or a pipe having the wrong slope.



It really does help to have good sized main vents so you clear out all the air fast, is there anyplace you might be able to drill and tap a hole for them? You might want to hire someone for that and don't try it in the middle of a heating season, just in case Mr Murphy pays you a visit. If that is impractical try large Gorton vent on the last radiator on each main and see how it works out.



My system has Hoffman 1A's and a couple of Ventrite #1 radiator vents on it. The Ventrites are probably 35 years old and have never caused a problem for me. I would not use the cheapo "Watts" adjustable bents you find in the big box stores.



If you don't already have it, pick up a copy of The Lost Art of Steam Heating available on this site, it will pay for itself 10X over.

good luck,



Bob

EHurley

Thank you and positioning main vents

Thank you, Danny, Chris, Nicholas, and Bob, I really appreciate your input and thoughts on my issues: it is a big help to me. Sorry for the delay in responding, I have purchased the venting booklet and will work on figuring out my air-capacity within my system and which Gorton vents are needed for the different radiators. I think I may explore the TRV option for the cold room a little down the road (the budget for this year is going to be mostly used up in buying the insulation), but it is good info and I’ll definitely explore them as an option down the road.



I am going to examine the pitch in my pipes.



A new question based on the feedback: I am going to take the advice of posting pictures (or do a diagram) to better show my system, but I am having a hard time visualizing where I should install the main vents – I seem to have three “branches” that come out of the near-boiler piping which, in turn, branch again, for example, the largest diameter pipe travels straight to the front of the house, tees off to literally the two corners of the house where a radiator is located. There is a condensate return pipe that also tees off and goes to the radiator as well. Should a main vent be located right before the tee or shortly before the branches reach the radiator?



I will post some pictures this evening, I wanted to be sure to communicate my gratitude before I let too much more time slip by!



Thank you again for taking the time to respond.



Sincerely,



Ed

BobC

Mains configuration

A steam main carries steam to different areas and the radiator feeds branch off this, there can be one or a number of them depending on the layout. Steam mains are usually 2, 2-1/2" or larger with radiator feeders being smaller (1, 1-1/4 or sometimes1-1/2") The ideal location for a main vent is about 18" past the last radiator takeoff but that isn't always possible. All pipe diameters are ID so the pipe appears larger because the steel walls are pretty robust.



Steam systems can be parallel (the steam and water flow in the same direction) where the main starts high above the boilerand drops slightly as it goes along, at the end it drops to the bottom of the boiler to feed the condensed steam back to the boiler. The air vent is after the last radiator takeoff and it can be close to the boiler or 20 feet away depending on the layout.



Steam systems can also be counterflow where the steam main slopes gently up as it runs away from the boiler. The condensed steam runs back through the steam main to return to the boiler (the condensed water runs in the opposite direction as the the steam), the air vent is usually near the end of the main after the last radiator takeoff, it is almost always pretty far away from the boiler.



Some systems use both parallel and counterflow mains on the same system, it's important to know which is which because the slopes are different.



My main vent is at the end of the main where it dives for the floor to become the return, that is a bad spot because it places the vent in an area where it can get slammed. I solved that by running a 16" lateral back along the main and putting the air vent there where it is isolated from any turbulence.



As you can tell this is not hard but it does get somewhat fussy. Heating Help has the "Lost Art of Steam Heating" on sale this week for $10 off, that book will make everything very easy to understand. I wish someone like Dan had written my textbooks when i was in school!



Bob